83 results on '"Ehlers MM"'
Search Results
2. Global diversity and antimicrobial resistance of typhoid fever pathogens: Insights from a meta-analysis of 13,000 Salmonella Typhi genomes.
- Author
-
Carey, ME, Dyson, ZA, Ingle, DJ, Amir, A, Aworh, MK, Chattaway, MA, Chew, KL, Crump, JA, Feasey, NA, Howden, BP, Keddy, KH, Maes, M, Parry, CM, Van Puyvelde, S, Webb, HE, Afolayan, AO, Alexander, AP, Anandan, S, Andrews, JR, Ashton, PM, Basnyat, B, Bavdekar, A, Bogoch, II, Clemens, JD, da Silva, KE, De, A, de Ligt, J, Diaz Guevara, PL, Dolecek, C, Dutta, S, Ehlers, MM, Francois Watkins, L, Garrett, DO, Godbole, G, Gordon, MA, Greenhill, AR, Griffin, C, Gupta, M, Hendriksen, RS, Heyderman, RS, Hooda, Y, Hormazabal, JC, Ikhimiukor, OO, Iqbal, J, Jacob, JJ, Jenkins, C, Jinka, DR, John, J, Kang, G, Kanteh, A, Kapil, A, Karkey, A, Kariuki, S, Kingsley, RA, Koshy, RM, Lauer, AC, Levine, MM, Lingegowda, RK, Luby, SP, Mackenzie, GA, Mashe, T, Msefula, C, Mutreja, A, Nagaraj, G, Nagaraj, S, Nair, S, Naseri, TK, Nimarota-Brown, S, Njamkepo, E, Okeke, IN, Perumal, SPB, Pollard, AJ, Pragasam, AK, Qadri, F, Qamar, FN, Rahman, SIA, Rambocus, SD, Rasko, DA, Ray, P, Robins-Browne, R, Rongsen-Chandola, T, Rutanga, JP, Saha, SK, Saha, S, Saigal, K, Sajib, MSI, Seidman, JC, Shakya, J, Shamanna, V, Shastri, J, Shrestha, R, Sia, S, Sikorski, MJ, Singh, A, Smith, AM, Tagg, KA, Tamrakar, D, Tanmoy, AM, Thomas, M, Thomas, MS, Thomsen, R, Thomson, NR, Tupua, S, Vaidya, K, Valcanis, M, Veeraraghavan, B, Weill, F-X, Wright, J, Dougan, G, Argimón, S, Keane, JA, Aanensen, DM, Baker, S, Holt, KE, Global Typhoid Genomics Consortium Group Authorship, Carey, ME, Dyson, ZA, Ingle, DJ, Amir, A, Aworh, MK, Chattaway, MA, Chew, KL, Crump, JA, Feasey, NA, Howden, BP, Keddy, KH, Maes, M, Parry, CM, Van Puyvelde, S, Webb, HE, Afolayan, AO, Alexander, AP, Anandan, S, Andrews, JR, Ashton, PM, Basnyat, B, Bavdekar, A, Bogoch, II, Clemens, JD, da Silva, KE, De, A, de Ligt, J, Diaz Guevara, PL, Dolecek, C, Dutta, S, Ehlers, MM, Francois Watkins, L, Garrett, DO, Godbole, G, Gordon, MA, Greenhill, AR, Griffin, C, Gupta, M, Hendriksen, RS, Heyderman, RS, Hooda, Y, Hormazabal, JC, Ikhimiukor, OO, Iqbal, J, Jacob, JJ, Jenkins, C, Jinka, DR, John, J, Kang, G, Kanteh, A, Kapil, A, Karkey, A, Kariuki, S, Kingsley, RA, Koshy, RM, Lauer, AC, Levine, MM, Lingegowda, RK, Luby, SP, Mackenzie, GA, Mashe, T, Msefula, C, Mutreja, A, Nagaraj, G, Nagaraj, S, Nair, S, Naseri, TK, Nimarota-Brown, S, Njamkepo, E, Okeke, IN, Perumal, SPB, Pollard, AJ, Pragasam, AK, Qadri, F, Qamar, FN, Rahman, SIA, Rambocus, SD, Rasko, DA, Ray, P, Robins-Browne, R, Rongsen-Chandola, T, Rutanga, JP, Saha, SK, Saha, S, Saigal, K, Sajib, MSI, Seidman, JC, Shakya, J, Shamanna, V, Shastri, J, Shrestha, R, Sia, S, Sikorski, MJ, Singh, A, Smith, AM, Tagg, KA, Tamrakar, D, Tanmoy, AM, Thomas, M, Thomas, MS, Thomsen, R, Thomson, NR, Tupua, S, Vaidya, K, Valcanis, M, Veeraraghavan, B, Weill, F-X, Wright, J, Dougan, G, Argimón, S, Keane, JA, Aanensen, DM, Baker, S, Holt, KE, and Global Typhoid Genomics Consortium Group Authorship
- Abstract
BACKGROUND: The Global Typhoid Genomics Consortium was established to bring together the typhoid research community to aggregate and analyse Salmonella enterica serovar Typhi (Typhi) genomic data to inform public health action. This analysis, which marks 22 years since the publication of the first Typhi genome, represents the largest Typhi genome sequence collection to date (n=13,000). METHODS: This is a meta-analysis of global genotype and antimicrobial resistance (AMR) determinants extracted from previously sequenced genome data and analysed using consistent methods implemented in open analysis platforms GenoTyphi and Pathogenwatch. RESULTS: Compared with previous global snapshots, the data highlight that genotype 4.3.1 (H58) has not spread beyond Asia and Eastern/Southern Africa; in other regions, distinct genotypes dominate and have independently evolved AMR. Data gaps remain in many parts of the world, and we show the potential of travel-associated sequences to provide informal 'sentinel' surveillance for such locations. The data indicate that ciprofloxacin non-susceptibility (>1 resistance determinant) is widespread across geographies and genotypes, with high-level ciprofloxacin resistance (≥3 determinants) reaching 20% prevalence in South Asia. Extensively drug-resistant (XDR) typhoid has become dominant in Pakistan (70% in 2020) but has not yet become established elsewhere. Ceftriaxone resistance has emerged in eight non-XDR genotypes, including a ciprofloxacin-resistant lineage (4.3.1.2.1) in India. Azithromycin resistance mutations were detected at low prevalence in South Asia, including in two common ciprofloxacin-resistant genotypes. CONCLUSIONS: The consortium's aim is to encourage continued data sharing and collaboration to monitor the emergence and global spread of AMR Typhi, and to inform decision-making around the introduction of typhoid conjugate vaccines (TCVs) and other prevention and control strategies. FUNDING: No specific funding was awarded f
- Published
- 2023
3. Assessment of Atopobium vaginae and Gardnerella vaginalis concentrations in a cohort of pregnant South African women
- Author
-
Redelinghuys, MJ, Ehlers, MM, Bezuidenhoudt, JE, Becker, PJ, and Kock, MM
- Published
- 2017
- Full Text
- View/download PDF
4. Additional file 1 of Comparison of targeted metagenomics and IS-Pro methods for analysing the lung microbiome
- Author
-
Goolam Mahomed, T, Peters, RPH, Pretorius, GHJ, Goolam Mahomed, A, Ueckermann, V, Kock, MM, and Ehlers, MM
- Abstract
Additional file 1: Table S1. Inclusion and exclusion criteria for COPD patients in this study. Table S2. Clinical characteristic of patients. Table S3. Comparison of the number of amplicons and operational taxonomic units for each sample for the targeted metagenomics and IS-Pro methods. Figure S1. Relative abundance of specific phyla in the sputum microbiome of COPD participants as detected by targeted metagenomics and IS-Pro methods (n = 23). The dots represent the different abundances of each sample, according to the different phyla. Phyla that are depicted with a single line on the y-axis were not present in any samples for that method. Figure S2. Bar plots showing the relative abundance of genera in the sputum microbiome of COPD participants as characterised by targeted metagenomics and IS-Pro methods (n = 23). The operational taxonomic units that could not be classified at a genus level are indicated as NA on the graph. Figure S3. The distribution of the unclassified operational taxonomic units (OTUs) at a class level of the sputum microbiome of COPD participants for targeted metagenomics and IS-Pro methods by phyla. At a class level, all the OTUs from targeted metagenomics could be classified.
- Published
- 2021
- Full Text
- View/download PDF
5. Contributors
- Author
-
Anderson, GK, primary, Arbord, JP, additional, Atkinson, B, additional, Barford, JP, additional, Barton, GW, additional, Bartram, Jamie, additional, Binkley, John, additional, Boon, Arthur G, additional, Bromley-Challenor, K C A, additional, Chan, E C S, additional, Cloete, TE, additional, Codony, Franscisc, additional, Curtis, Tom, additional, Drasar, BS, additional, Ehlers, MM, additional, Ekama, GA, additional, Fattal, Badri, additional, Feachem, R G A, additional, Fitzpatrick, Caroline S, additional, Foot, RJ, additional, Gale, Paul, additional, Godfree, A, additional, Gregory, John, additional, Grimason, AM, additional, Handley, Pauline S, additional, Hao, Oliver J, additional, Heritage, John, additional, Horan, Nigel, additional, Howard, Guy, additional, Huffman, Debra E, additional, Johnstone, David W M, additional, Kator, Howard, additional, Kelley, Joan, additional, Kerr, Charmain J, additional, Kinsey, Graham, additional, Knapp, JS, additional, Bihan, Yann Le, additional, Lessard, Paul, additional, Loewenthal, RE, additional, Madoni, Paolo, additional, Mara, DD, additional, Mas, J, additional, Melo, Luís F, additional, Mir, J, additional, Morató, J, additional, Morris, R, additional, Murchie, Peter, additional, Oragui, John, additional, Ortenberg, Esther, additional, Osborn, Keith S, additional, Paterson, Russell, additional, Payment, Pierre, additional, Pearson, Howard, additional, Pinfold, John, additional, Quintero-Betancourt, Walter, additional, Rhodes, Martha, additional, Ribas, F, additional, Rickard, Alex H, additional, Robinson, MS, additional, Robson, Geoff D, additional, Rose, Joan B, additional, Sallis, PJ, additional, Schroeder, Edward D, additional, Shuval, Hillel, additional, Simpson, JA, additional, Smith, HV, additional, Stott, Rebecca, additional, Taylor, Huw, additional, Teltsch, Benjamin, additional, Uyanik, S, additional, van Heerden, J., additional, Vincent, Alison J, additional, Wentzel, MC, additional, Wong, CH, additional, and Wuertz, Stefan, additional
- Published
- 2003
- Full Text
- View/download PDF
6. Assessment ofAtopobium vaginaeandGardnerella vaginalisconcentrations in a cohort of pregnant South African women
- Author
-
Redelinghuys, MJ, primary, Ehlers, MM, additional, Bezuidenhoudt, JE, additional, Becker, PJ, additional, and Kock, MM, additional
- Published
- 2017
- Full Text
- View/download PDF
7. Biolog identification of non-sorbitol fermenting bacteria isolated on E. coli O157 selective CT-SMAC agar
- Author
-
Müller, EE and Ehlers, MM
- Abstract
E. coli O157:H7 is recognised as an important human pathogen world-wide and has been associated with diseases such as haemorrhagic colitis (HC), haemolytic uraemic syndrome (HUS) and thrombotic thrombocytopaenic purpura (TTP). Accurate laboratory detection of E. coli O157:H7 is important for diagnostic purposes and to justify epidemiological data on E. coli O157:H7. A well-known phenotypic characteristic of E. coli O157:H7 bacteria is their inability to ferment sorbitol. This characteristic is often used to isolate these organisms from food and water using selective agar medium such as SMAC. However, the high number of false positive results obtained by a number of researchers when selectively screening for E. coli O157: H7 on CT-SMAC has prompted an investigation to determine which other sorbitol-negative bacteria also grow on CT-SMAC. The agar medium used for the investigation consisted of Sorbitol MacConkey agar (SMAC) supplemented with Cefiximetellurite (CT). All sorbitol-negative colonies obtained from CT-SMAC, after selective enrichment and IMS were identified using the Biolog microbial identification system. The majority of sorbitol-negative isolates identified were Burkholderia, Pseudomonas, Vibrio and Aeromonas spp. Only two E. coli O157:H7 isolates were identified with Biolog and confirmed with a polymerase chain reaction (PCR) specific for the shiga toxin 1 (Stx1) genes and with O157 and H7 antisera. The inability of the CT-SMAC agar medium to specifically select for E.coli O157:H7 was confirmed by the results of this study. These observations call for further improvement of affordable methods for the selective isolation of E. coli O157:H7 in the presence of large numbers of interfering bacteria capable of growing on CT-SMAC. Water SA Vol. 31 (2) 2005: pp.247-252
- Published
- 2007
8. Immunomagnetic separation of Escherichia coli O157:H7 from environmental and wastewater in South Africa
- Author
-
Muller, EE, Grabow, WOK, and Ehlers, MM
- Subjects
Escherichia coli O157:H7 ,Immunomagnetic separation ,River water ,Sewage - Abstract
Recreational and drinking water supplies polluted with sewage have become an important source of E. coli O157:H7 infection. Immunomagnetic separation (IMS) has been extensively used for the isolation of E. coli O157:H7 from food and stool samples but not for samples such as wastewater. In this study the IMS method was used in combination with the E. coli O157:H7 selective media, immunoassays, biochemical tests and PCR, to assess the prevalence of E. coli O157:H7 in selected sewage and environmental water in South Africa. Environmental and wastewater were seeded with E. coli O157:H7 to determine the sensitivity and selectivity of the enrichment-IMS-selective agar method. Naturally occurring E. coli O157:H7 organisms were recovered from selected samples by means of IMS. The IMS concentrates were plated on three selective E. coli O157:H7 media. E. coli O157:H7 was detected in seeded sewage and river water samples with numbers as low as 1.2 cfu.ml-1. The IMS procedure was used to investigate the prevalence of E. coli O157:H7 in randomly selected sewage and river water samples in South Africa. A total of 91 sewage- and 40 river water samples were tested and 17.6% and 20% yielded suspected E. coli O157:H7 colonies on CT-SMAC agar medium respectively. PCR was used to confirm the presence of genes coding for Shiga toxin-1 (Stx1), Shiga toxin-2 (Stx2), enterocyte attaching and effacing genes (eaeA) and enterohaemolysin (hly). Standard immunoassay kits specific for the O157 and H7 antigen and a biochemical indole test were used for further E. coli O157:H7 confirmation. Three colonies from one sewage sample (1.1 % of all sewage samples) agglutinated with anti-E. coli O157 and H7 antiserum and contained the genes coding for Stx2, eaeA and hly. None of the colonies isolated from the river water samples were positive for E. coli O157:H7. CT-SMAC proved to have limited E. coli O157:H7 selective capabilities from samples such as sewage with high bacterial counts. Seeded sample experiments indicated that IMS is a suitable method for isolating E. coli O157:H7 from samples with high bacterial interference and low numbers of E. coli O157:H7. Evidence has been presented that the enrichment-IMS-selective agar procedure substantially increased the sensitivity of E. coli O157:H7 isolation compared to direct plating of test samples onto selective agar generally practised in the past. WaterSA Vol.29(4) 2003: 427-432
- Published
- 2004
9. Assessment of Atopobium vaginaeand Gardnerella vaginalisconcentrations in a cohort of pregnant South African women
- Author
-
Redelinghuys, MJ, Ehlers, MM, Bezuidenhoudt, JE, Becker, PJ, and Kock, MM
- Abstract
ObjectivesThe purpose of this cross-sectional study was to assess Atopobium vaginaeand Gardnerella vaginalisconcentrations in pregnant women of different age groups, gestational age groups, vaginal flora categories and HIV status, and also to determine which DNA concentrations best discriminated between bacterial vaginosis (BV)-positive and non-BV categories.MethodsSelf-collected vaginal swabs were obtained from 220 pregnant women attending an antenatal clinic in Pretoria, Gauteng, South Africa, from July 2012 to December 2012. BV was detected with the Nugent scoring system, and A. vaginaeand G. vaginalisDNA was quantified with a multiplex quantitative real-time PCR assay.ResultsMedian concentrations of A. vaginaeand G. vaginaliswere not significantly different among various age groups (A. vaginaep=0.98 and G. vaginalisp=0.18) or different trimesters (A. vaginaep=0.31 and G. vaginalisp=0.19), but differed significantly among the vaginal flora categories (A. vaginaep<0.001 and G. vaginalisp<0.001) and HIV status (A. vaginaep<0.001 and G. vaginalisp=0.004). The presence of A. vaginae(OR=5.8; 95% CI 1.34 to 25.21 and p value=0.02) but not that of G. vaginalis(OR=1.90; 95% CI 0.81 to 4.43 and p value=0.14) was associated with HIV infection. An A. vaginaeDNA concentration of ≥107copies/mL together with a positive G. vaginalisresult (≥100copies/mL) best discriminated between BV-positive (39/220) and non-BV categories (181/220) with a sensitivity of 85% (95% CI 0.70 to 0.94) and a specificity of 82% (95% CI 0.76 to 0.88).ConclusionsA. vaginaeand G. vaginaliswere present in high numbers and concentrations in this pregnant cohort. Threshold concentrations should be established for specific populations to ensure sensitive molecular assays for BV detection.
- Published
- 2017
- Full Text
- View/download PDF
10. Studies to distinguish between human and animal faecal pollution using F-RNA coliphages and faecal sterols
- Author
-
Sundram, A, primary, Jumanlal, N, additional, and Ehlers, MM, additional
- Published
- 2009
- Full Text
- View/download PDF
11. Evaluation of the CDC safe water-storage intervention to improve the microbiological quality of point-of-use drinking water in rural communities in South Africa
- Author
-
Potgieter, N, primary, Becker, PJ, additional, and Ehlers, MM, additional
- Published
- 2009
- Full Text
- View/download PDF
12. Genotyping of F-RNA coliphages isolated from wastewater and river water samples
- Author
-
Sundram, A, primary, Jumanlal, N, additional, and Ehlers, MM, additional
- Published
- 2007
- Full Text
- View/download PDF
13. Biolog for the determination of diversity in microbial communities
- Author
-
Van Heerden, J, primary, Korf, C, additional, Ehlers, MM, additional, and Cloete, TE, additional
- Published
- 2004
- Full Text
- View/download PDF
14. Epidemiology and antimicrobial resistance profiles of pathogenic Escherichia coli from commercial swine and poultry abattoirs and farms in South Africa: A One Health approach.
- Author
-
Ogundare ST, Fasina FO, Makumbi JP, van der Zel GA, Geertsma PF, Kock MM, Smith AM, and Ehlers MM
- Subjects
- Animals, South Africa epidemiology, Swine, One Health, Humans, Anti-Bacterial Agents pharmacology, Escherichia coli Infections epidemiology, Escherichia coli Infections veterinary, Escherichia coli Infections microbiology, Drug Resistance, Bacterial genetics, Abattoirs, Escherichia coli drug effects, Escherichia coli genetics, Poultry, Farms
- Abstract
Pathogenic Escherichia coli (PEC) are important foodborne bacteria that can cause severe illness in humans. The PECs thrive within the intestines of humans as well as animals and may contaminate multiple ecosystems, including food and water, via faecal transmission. Abattoir and farm employees are at high risk of PEC exposure, which could translate to community risk through person-to-person contact. To determine the epidemiology and resistome of PECs in Gauteng and Limpopo provinces of South Africa, 198 swine faecal samples, 220 poultry cloacal swabs, 108 human hand swabs, 11 run-off water samples from abattoirs and farms were collected from four swine and five poultry commercial abattoirs and two swine farms. One effluent sample each was collected from four wastewater treatment plants (WWTP) and a tertiary hospital setting. Phenotypic and genotypic techniques were used including polymerase chain reaction, pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). Results showed EHEC and EPEC prevalence was 4.1 % (22/542) and 20.8 % (113/542), respectively, with the O26 serogroup detected the most in PEC isolates. According to the PFGE dendrogram, isolates from poultry, human hand swabs and run-off water clustered together. Diverse virulence factors such as the novel stx2k subtype and eae genes were detected among the 36 representative PEC isolates according to WGS. The results showed that 66.7 % (24/36) of sequenced PECs presented with multi-drug resistance (MDR) to β-lactamase 13.9 % (5/36), aminoglycoside 61.1 % (22/36), tetracycline 41.7 % (15/36) and quinolones 38.9 % (14/36). No colistin nor carbapenem resistance was detected. Sequence types (STs) associated with MDR in this study were: ST752, ST189, ST206, ST10, ST48 and ST38. The findings highlight the threat of zoonotic pathogens to close human contacts and the need for enhanced surveillance to mitigate the spread of MDR foodborne PECs., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Samuel T. Ogundare reports financial support was provided by National Research Foundation. Anthony M Smith reports financial support was provided by United Kingdom Department of Health and Social Care. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
15. Molecular epidemiology of carbapenemase-producing Klebsiella pneumoniae in Gauteng South Africa.
- Author
-
Salvador-Oke KT, Pitout JDD, Peirano G, Strydom KA, Kingsburgh C, Ehlers MM, Ismail A, Takawira FT, and Kock MM
- Subjects
- South Africa epidemiology, Humans, Microbial Sensitivity Tests, Drug Resistance, Multiple, Bacterial genetics, Whole Genome Sequencing, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Klebsiella pneumoniae genetics, Klebsiella pneumoniae enzymology, Klebsiella pneumoniae drug effects, Klebsiella pneumoniae isolation & purification, beta-Lactamases genetics, beta-Lactamases metabolism, Bacterial Proteins genetics, Bacterial Proteins metabolism, Klebsiella Infections epidemiology, Klebsiella Infections microbiology, Molecular Epidemiology
- Abstract
Klebsiella pneumoniae multidrug-resistant (MDR) high-risk clones drive the spread of antimicrobial resistance (AMR) associated infections, resulting in limited therapeutic options. This study described the genomic characteristics of K. pneumoniae MDR high-risk clones in Gauteng, South Africa. Representative carbapenem-resistant [K. pneumoniae carbapenemase (KPC)-2, New-Delhi metallo-beta (β)-lactamase (NDM)-1, oxacillinase (OXA)-181, OXA-232, OXA-48, Verona integron-encoded metallo-β-lactamase (VIM)-1] K. pneumoniae isolates (n = 22) obtained from inpatient and outpatient's urine (n = 9) and inpatients rectal carriage (n = 13) were selected for short-read whole genome sequencing. Klebsiella pneumoniae population include sequence type (ST)-307 (n = 3), ST2497 (n = 5) and ST17 (n = 4). The ST17 strains were exclusively obtained from rectal screening. Ten isolates co-harboured carbapenemase genes including β-lactamase gene encoding KPC-2 + OXA-181, NDM-1 + OXA-48 and NDM-1 + OXA-181. One ST307 isolate (UP-KT-73CKP) co-harboured three carbapenemase genes (bla
NDM-1 + blaOXA-48 + blaOXA-181 ), while all the ST2497 strains co-harboured (blaNDM-1 + blaOXA-232 ). Phenotypically, hypermucoviscosity was observed in a single ST307 isolate. The ST307 isolate UP-KT-151UKP harboured colibactin genotoxins. The following mobile genetic elements were detected: plasmids [incompatibility group (Inc)-FIB(K), IncX3], and bacteriophages [e.g. Klebsi_ST16_OXA48phi5.4_NC_049450, Klebsi_3LV2017_NC_047817(36)]. The study highlights the importance of local genomic surveillance systems to characterise K. pneumoniae MDR high-risk clones. This data will aid in designing infection and prevention measures for limiting the spread of carbapenemase-producing K. pneumoniae in Gauteng, South Africa., (© 2024. The Author(s).)- Published
- 2024
- Full Text
- View/download PDF
16. Klebsiella pneumoniae with carbapenemases: high prevalence of sequence type 307 with bla OXA181 in South African community hospitals.
- Author
-
Salvador-Oke KT, Pitout JDD, Peirano G, Strydom KA, Kingsburgh C, Ehlers MM, and Kock MM
- Subjects
- Humans, South Africa epidemiology, Prevalence, Plasmids genetics, Drug Resistance, Multiple, Bacterial genetics, Microbial Sensitivity Tests, Urinary Tract Infections microbiology, Urinary Tract Infections epidemiology, Urinary Tract Infections drug therapy, Ceftazidime pharmacology, Ceftazidime therapeutic use, Azabicyclo Compounds pharmacology, Klebsiella pneumoniae genetics, Klebsiella pneumoniae drug effects, Klebsiella pneumoniae enzymology, beta-Lactamases genetics, Bacterial Proteins genetics, Klebsiella Infections microbiology, Klebsiella Infections epidemiology, Klebsiella Infections drug therapy, Hospitals, Community, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use
- Abstract
This study investigated the molecular characteristics of urinary carbapenemase-producing Klebsiella pneumoniae isolates (n = 194) in Gauteng, South Africa, using simple, cost-effective PCR methodologies. Extensively drug resistant (XDR) ST307 with bla
OXA-181 on IncX3 plasmids was endemic in Gauteng community hospitals leaving limited options for treating in- and outpatient urinary tract infections. High-level ceftazidime/avibactam resistance was detected among isolates harbouring blaOXA-48-like including blaOXA-181 . These findings highlighted the need for genomic methodologies suitable for lower- and middle-income countries to track XDR clones and plasmids in community hospitals. Such results will aid with treatment and stewardship strategies., (© 2024. The Author(s).)- Published
- 2024
- Full Text
- View/download PDF
17. Detection of the epidemic Pseudomonas aeruginosa AUST-03 (ST242) strain in people with cystic fibrosis in South Africa.
- Author
-
Hamiwe T, White DA, Kwenda S, Ismail A, Klugman S, Van Bruwaene L, Goga A, Kock MM, Smith AM, and Ehlers MM
- Abstract
Introduction: Pseudomonas aeruginosa AUST-03 (ST242) has been reported to cause epidemics in people with CF (pwCF) from Australia and has been associated with multidrug resistance and increased morbidity and mortality. Here, we report an epidemic P. aeruginosa (AUST-03) strain in South African pwCF detected at a public hospital and characterize the genomic antibiotic resistance determinants., Methods: The P. aeruginosa AUST-03 (ST242) study isolates were analysed with whole genome sequencing using the Illumina NextSeq2000 platform. Raw sequencing reads were processed using the Jekesa pipeline and multilocus sequence typing and genomic antibiotic resistance characterization was performed using public databases. Genetic relatedness between the study isolates and global P. aeruginosa ST242 from public databases was determined using a maximum-likelihood phylogenetic tree. Antibiotic susceptibility testing was performed using the disk diffusion and broth microdilution techniques., Results: A total of 11 P. aeruginosa AUST-03 isolates were isolated from two children with CF. The majority (8/11) of these isolates were multidrug-resistant (MDR) or extensively drug resistant; and the multidrug efflux pumps MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY-OprM were the most clinically relevant antibiotic resistance determinants and were detected in all of the isolates. The study isolates were the most closely related to a 2020 P. aeruginosa AUST-03 (ST242) CF isolate from Russia., Conclusion: Epidemic MDR P. aeruginosa strains are present at South African public CF clinics and need to be considered when implementing segregation and infection control strategies to prevent possible spread and outbreaks., (© 2024 The Author(s). Pediatric Pulmonology published by Wiley Periodicals LLC.)
- Published
- 2024
- Full Text
- View/download PDF
18. Genomic epidemiology and molecular characteristics of bla NDM-1 -positive carbapenem-resistant Pseudomonas aeruginosa belonging to international high-risk clone ST773 in the Gauteng region, South Africa.
- Author
-
Jung H, Pitout JDD, Matsumura Y, Strydom KA, Kingsburgh C, Ehlers MM, and Kock MM
- Subjects
- Humans, Phylogeny, South Africa epidemiology, beta-Lactamases genetics, Carbapenems pharmacology, Genomics, Microbial Sensitivity Tests, Pseudomonas aeruginosa, Anti-Bacterial Agents pharmacology
- Abstract
Purpose: The emergence of carbapenem-resistant P. aeruginosa (CRPA) harbouring acquired carbapenemase genes (bla
VIM , blaIMP and blaNDM ) has become a global public health threat. Three CRPA isolates included in the study had an extensively drug-resistant phenotype with susceptibility to colistin only and were positive for the blaNDM-1 gene. The current study aimed to investigate the genomic epidemiology and molecular characteristics of the blaNDM-1 -positive CRPA isolates collected from the Gauteng region, South Africa., Methods: Short read whole genome sequencing (WGS) was performed to determine sequence types (STs), genetic relatedness, resistome, virulome and the genetic environment of the blaNDM-1 gene., Results: The WGS and phylogenetic analyses revealed that the study isolates belonged to an international high-risk clone ST773 and belonged to the same clade with eight blaNDM-1 -positive ST773 isolates from Hungary, India, Nigeria, South Korea and USA. The study isolates harboured a wide repertoire of intrinsic and acquired antibiotic resistance genes (ARGs) related with mobile genetic elements, porins and efflux pumps, as well as virulence factor genes. The clade-specific ARGs (blaNDM-1 , floR2/cmlA9, rmtB4, tetG) were found in a putative integrative and conjugative element (ICE) region similar to ICE6660-like., Conclusion: As ICE carrying the blaNDM-1 gene can easily spread to other P. aeruginosa isolates and other Gram-negative bacteria, the findings in this study highlight the need for appropriate management strategies and active surveillance of CRPA isolates in the Gauteng region, South Africa., (© 2024. The Author(s).)- Published
- 2024
- Full Text
- View/download PDF
19. Population structure of Salmonella enterica Typhi in Harare, Zimbabwe (2012-19) before typhoid conjugate vaccine roll-out: a genomic epidemiology study.
- Author
-
Thilliez G, Mashe T, Chaibva BV, Robertson V, Bawn M, Tarupiwa A, Takawira FT, Kock MM, Midzi S, Mwamakamba LW, Matheu J, Juru A, Kingsley RA, and Ehlers MM
- Subjects
- Humans, Vaccines, Conjugate, Zimbabwe epidemiology, Phylogeny, Salmonella typhi genetics, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Genomics, Typhoid Fever epidemiology, Typhoid Fever prevention & control, Salmonella enterica, Typhoid-Paratyphoid Vaccines pharmacology, Quinolones pharmacology
- Abstract
Background: The continued emergence of Salmonella enterica serovar Typhi, with ever increasing antimicrobial resistance, necessitates the use of vaccines in endemic countries. A typhoid fever outbreak in Harare, Zimbabwe, in 2018 from a multidrug resistant S Typhi with additional resistance to ciprofloxacin was the catalyst for the introduction of a typhoid conjugate vaccine programme. We aimed to investigate the emergence and evolution of antimicrobial resistance of endemic S Typhi in Zimbabwe and to determine the population structure, gene flux, and sequence polymorphisms of strains isolated before a typhoid conjugate vaccine programme to provide a baseline for future evaluation of the effect of the vaccination programme., Methods: In this genomic epidemiology study, we used short-read whole-genome sequencing of S Typhi isolated from clinical cases of typhoid fever in Harare, Zimbabwe, between Jan 1, 2012, and Feb 9, 2019, to determine the S Typhi population structure, gene flux, and sequence polymorphisms and reconstructed the evolution of antimicrobial resistance. Maximum likelihood time-scaled phylogenetic trees of Zimbabwe isolates in the context of global isolates obtained from the National Center for Biotechnology Information were constructed to infer spread and emergence of antimicrobial resistance., Findings: The population structure of S Typhi in Harare, Zimbabwe, from 2012 to 2019 was dominated by multidrug resistant genotype 4.3.1.1.EA1 (H58) that spread to Zimbabwe from neighbouring countries in around 2009 (95% credible interval 2008·5-2010·0). Acquisition of an IncN plasmid carrying antimicrobial resistance genes including a qnrS gene and a mutation in the quinolone resistance determining region of gyrA gene contributed to non-susceptibility and resistance to quinolone antibiotics. A minority population of antimicrobial susceptible S Typhi genotype 3.3.1 strains were present throughout., Interpretation: The currently dominant S Typhi population is genotype 4.3.1.1 that spread to Zimbabwe and acquired additional antimicrobial resistance though acquisition of a plasmid and mutation in the gyrA gene. This study provides a baseline population structure for future evaluation of the effect of the typhoid conjugate vaccine programme in Harare., Funding: Bill & Melinda Gates Foundation and the Biotechnology and Biological Sciences Research Council Institute Strategic Programme., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
20. Global diversity and antimicrobial resistance of typhoid fever pathogens: Insights from a meta-analysis of 13,000 Salmonella Typhi genomes.
- Author
-
Carey ME, Dyson ZA, Ingle DJ, Amir A, Aworh MK, Chattaway MA, Chew KL, Crump JA, Feasey NA, Howden BP, Keddy KH, Maes M, Parry CM, Van Puyvelde S, Webb HE, Afolayan AO, Alexander AP, Anandan S, Andrews JR, Ashton PM, Basnyat B, Bavdekar A, Bogoch II, Clemens JD, da Silva KE, De A, de Ligt J, Diaz Guevara PL, Dolecek C, Dutta S, Ehlers MM, Francois Watkins L, Garrett DO, Godbole G, Gordon MA, Greenhill AR, Griffin C, Gupta M, Hendriksen RS, Heyderman RS, Hooda Y, Hormazabal JC, Ikhimiukor OO, Iqbal J, Jacob JJ, Jenkins C, Jinka DR, John J, Kang G, Kanteh A, Kapil A, Karkey A, Kariuki S, Kingsley RA, Koshy RM, Lauer AC, Levine MM, Lingegowda RK, Luby SP, Mackenzie GA, Mashe T, Msefula C, Mutreja A, Nagaraj G, Nagaraj S, Nair S, Naseri TK, Nimarota-Brown S, Njamkepo E, Okeke IN, Perumal SPB, Pollard AJ, Pragasam AK, Qadri F, Qamar FN, Rahman SIA, Rambocus SD, Rasko DA, Ray P, Robins-Browne R, Rongsen-Chandola T, Rutanga JP, Saha SK, Saha S, Saigal K, Sajib MSI, Seidman JC, Shakya J, Shamanna V, Shastri J, Shrestha R, Sia S, Sikorski MJ, Singh A, Smith AM, Tagg KA, Tamrakar D, Tanmoy AM, Thomas M, Thomas MS, Thomsen R, Thomson NR, Tupua S, Vaidya K, Valcanis M, Veeraraghavan B, Weill FX, Wright J, Dougan G, Argimón S, Keane JA, Aanensen DM, Baker S, and Holt KE
- Subjects
- Humans, Anti-Bacterial Agents pharmacology, Travel, Drug Resistance, Bacterial genetics, Ciprofloxacin, Salmonella typhi genetics, Typhoid Fever epidemiology
- Abstract
Background: The Global Typhoid Genomics Consortium was established to bring together the typhoid research community to aggregate and analyse Salmonella enterica serovar Typhi (Typhi) genomic data to inform public health action. This analysis, which marks 22 years since the publication of the first Typhi genome, represents the largest Typhi genome sequence collection to date (n=13,000)., Methods: This is a meta-analysis of global genotype and antimicrobial resistance (AMR) determinants extracted from previously sequenced genome data and analysed using consistent methods implemented in open analysis platforms GenoTyphi and Pathogenwatch., Results: Compared with previous global snapshots, the data highlight that genotype 4.3.1 (H58) has not spread beyond Asia and Eastern/Southern Africa; in other regions, distinct genotypes dominate and have independently evolved AMR. Data gaps remain in many parts of the world, and we show the potential of travel-associated sequences to provide informal 'sentinel' surveillance for such locations. The data indicate that ciprofloxacin non-susceptibility (>1 resistance determinant) is widespread across geographies and genotypes, with high-level ciprofloxacin resistance (≥3 determinants) reaching 20% prevalence in South Asia. Extensively drug-resistant (XDR) typhoid has become dominant in Pakistan (70% in 2020) but has not yet become established elsewhere. Ceftriaxone resistance has emerged in eight non-XDR genotypes, including a ciprofloxacin-resistant lineage (4.3.1.2.1) in India. Azithromycin resistance mutations were detected at low prevalence in South Asia, including in two common ciprofloxacin-resistant genotypes., Conclusions: The consortium's aim is to encourage continued data sharing and collaboration to monitor the emergence and global spread of AMR Typhi, and to inform decision-making around the introduction of typhoid conjugate vaccines (TCVs) and other prevention and control strategies., Funding: No specific funding was awarded for this meta-analysis. Coordinators were supported by fellowships from the European Union (ZAD received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 845681), the Wellcome Trust (SB, Wellcome Trust Senior Fellowship), and the National Health and Medical Research Council (DJI is supported by an NHMRC Investigator Grant [GNT1195210])., Competing Interests: MC, ZD, DI, AA, MA, MC, KC, JC, BH, KK, MM, CP, SV, HW, AA, AA, SA, JA, PA, BB, AB, JC, Kd, AD, Jd, PD, CD, SD, ME, LF, DG, GG, MG, AG, CG, MG, RH, RH, YH, JH, OI, JI, JJ, CJ, DJ, JJ, GK, AK, AK, AK, SK, RK, RK, AL, ML, RL, SL, GM, TM, CM, AM, GN, SN, SN, TN, SN, EN, IO, SP, AP, FQ, FQ, SR, SR, DR, PR, RR, TR, JR, SS, SS, KS, MS, JS, JS, VS, JS, RS, SS, MS, AS, AS, KT, DT, AT, MT, MT, RT, NT, ST, KV, MV, BV, FW, JW, GD, SA, JK, DA, SB, KH No competing interests declared, NF NAF chairs the Wellcome Surveillance and Epidemiology of Drug Resistant Infections (SEDRIC) group, which has a focus on antimicrobial resistance. This could be perceived as relevant although not a direct conflict, IB IB has consulted to BlueDot and the NHL Players' Association, AP AJP is chair of the UK Department of Health and Social Care's (DHSC) Joint Committee on Vaccination and Immunisation (JCVI) but does not take part in the JCVI COVID-19 committee. He was a member of WHO SAGE until 2022. AJPs employer, Oxford University has entered into a partnership with AstraZeneca for development of a COVID-19 vaccine. AJP has provided advice to Shionogi & Co., Ltd on development of a COVID19 vaccine, (© 2023, Carey et al.)
- Published
- 2023
- Full Text
- View/download PDF
21. Faecal carriage of ESBL producing and colistin resistant Escherichia coli in avian species over a 2-year period (2017-2019) in Zimbabwe.
- Author
-
Takawira FT, Pitout JDD, Thilliez G, Mashe T, Gutierrez AV, Kingsley RA, Peirano G, Matheu J, Midzi SM, Mwamakamba LW, Gally DL, Tarupiwa A, Mukavhi L, Ehlers MM, Mtapuri-Zinyowera S, and Kock MM
- Subjects
- Animals, Anti-Bacterial Agents pharmacology, beta-Lactamases genetics, Chickens microbiology, Colistin, Escherichia coli genetics, Phylogeny, Poultry, Zimbabwe, Escherichia coli Infections microbiology, Escherichia coli Infections veterinary, Escherichia coli Proteins genetics
- Abstract
Introduction: Extended spectrum beta-lactamase (ESBL) producing Escherichia coli have become widespread among food producing animals. These strains serve as a reservoir of antibiotic resistance genes (ARGs) and act as a possible source of infection to humans as transmission can occur by direct or indirect contact., Methods: This study investigated the faecal carriage of ESBL producing and colistin resistant E. coli in poultry over a 2-year period (2017-2019) from Zimbabwe. A total of 21 ESBL positive isolates from poultry cloacal specimens were selected for whole genome sequencing from animal E. coli isolates bio-banked at the National Microbiology Reference laboratory using phenotypic susceptibility testing results from the National Escherichia coli Surveillance Program to provide representation of different geographical regions and year of isolation. Cloacal swabs were collected from 3000 broiler live birds from farm 1 and from farm 2, 40 backyard chickens and 10 ducks were sampled. Antimicrobial susceptibility and ESBL testing were performed as per Clinical Laboratory Standards Institute guidelines. Whole genome sequencing of ESBL producing isolates was used to determine sequence types (STs), ARGs, and phylogroups., Results: Twenty-one of the included E. coli isolates were confirmed as ESBL producers. Three defined sequence type clonal complexes (CCs) were identified (ST10CC, ST155CC and ST23CC), with ST10CC associated with the most antibiotic resistant profile. The ESBL phenotype was linked to the presence of either cefotaximase-Munich-14 (CTX-M-14) or CTX-M-79. Plasmid mediated quinolone resistant determinants identified were qnrB19 and qnrS1 and one ST10CC isolate from farm 1 broiler chickens harbored a mobile colistin resistance gene ( mcr-1 ). Phylogenetic groups most identified were B1, A and unknown., Discussions: The avian ESBL producing E. coli belonged to a diverse group of strains. The detection of several ARGs highlights the importance of implementing enhanced control measures to limit the spread in animals, environment, and humans. This is the first report of mcr-1 in Zimbabwe, which further underscores the importance of the One Health approach to control the spread and development of AMR., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Takawira, Pitout, Thilliez, Mashe, Gutierrez, Kingsley, Peirano, Matheu, Midzi, Mwamakamba, Gally, Tarupiwa, Mukavhi, Ehlers, Mtapuri-Zinyowera and Kock.)
- Published
- 2022
- Full Text
- View/download PDF
22. Multiclonal human origin and global expansion of an endemic bacterial pathogen of livestock.
- Author
-
Yebra G, Harling-Lee JD, Lycett S, Aarestrup FM, Larsen G, Cavaco LM, Seo KS, Abraham S, Norris JM, Schmidt T, Ehlers MM, Sordelli DO, Buzzola FR, Gebreyes WA, Gonçalves JL, Dos Santos MV, Zakaria Z, Rall VLM, Keane OM, Niedziela DA, Paterson GK, Holmes MA, Freeman TC, and Fitzgerald JR
- Subjects
- Female, Humans, Cattle, Animals, Livestock genetics, Genome, Host Specificity, Staphylococcus aureus genetics, Staphylococcal Infections epidemiology, Staphylococcal Infections veterinary, Staphylococcal Infections genetics
- Abstract
Most new pathogens of humans and animals arise via switching events from distinct host species. However, our understanding of the evolutionary and ecological drivers of successful host adaptation, expansion, and dissemination are limited. Staphylococcus aureus is a major bacterial pathogen of humans and a leading cause of mastitis in dairy cows worldwide. Here we trace the evolutionary history of bovine S. aureus using a global dataset of 10,254 S. aureus genomes including 1,896 bovine isolates from 32 countries in 6 continents. We identified 7 major contemporary endemic clones of S. aureus causing bovine mastitis around the world and traced them back to 4 independent host-jump events from humans that occurred up to 2,500 y ago. Individual clones emerged and underwent clonal expansion from the mid-19th to late 20th century coinciding with the commercialization and industrialization of dairy farming, and older lineages have become globally distributed via established cattle trade links. Importantly, we identified lineage-dependent differences in the frequency of host transmission events between humans and cows in both directions revealing high risk clones threatening veterinary and human health. Finally, pangenome network analysis revealed that some bovine S. aureus lineages contained distinct sets of bovine-associated genes, consistent with multiple trajectories to host adaptation via gene acquisition. Taken together, we have dissected the evolutionary history of a major endemic pathogen of livestock providing a comprehensive temporal, geographic, and gene-level perspective of its remarkable success.
- Published
- 2022
- Full Text
- View/download PDF
23. Diversity of the gut, vaginal and oral microbiome among pregnant women in South Africa with and without pre-eclampsia.
- Author
-
Geldenhuys J, Redelinghuys MJ, Lombaard HA, Ehlers MM, Cowan D, and Kock MM
- Abstract
Background: Changes in microbial communities are a known characteristic of various inflammatory diseases and have been linked to adverse pregnancy outcomes, such as preterm birth. However, there is a paucity of information regarding the taxonomic composition and/or diversity of microbial communities in pre-eclampsia. The aim of this study was to determine the diversity of the gut, vaginal and oral microbiome in a cohort of South African pregnant women with and without pre-eclampsia. The diversity of the gut, vaginal and oral microbiome was determined by targeted next generation sequencing (NGS) of the V3 and V4 region of the 16S rRNA gene on the Illumina MiSeq platform., Results: In this study population, pre-eclampsia was associated with a significantly higher alpha diversity ( P = 0.0472; indicated by the Shannon index) in the vaginal microbiome accompanied with a significant reduction in Lactobacillus spp. ( P = 0.0275), compared to normotensive pregnant women. Lactobacillus iners was identified as the predominant species of the vaginal microbiome in both cohorts. High inter-individual variation in alpha diversity was observed in the gut and oral microbiome in both cohorts. Although differences in the relative abundance of bacteria at all phylogenetic levels were observed, overall microbial composition of the gut, oral and vaginal microbiome was not significantly different in the pre-eclampsia cohort compared to the normotensive cohort., Conclusion: Collectively, a reduction of Lactobacillus spp., and predominance of L. iners in pregnant women with pre-eclampsia could suggest an unstable vaginal microbiome that might predispose pregnant women to develop pre-eclampsia. The lack of significant structural changes in the gut, oral and vaginal microbiome does not suggest that the characterized communities play a role in pre-eclampsia, but could indicate a characteristic unique to the study population. The current study provided novel information on the diversity of the gut, oral and vaginal microbiome among pregnant women in South Africa with and without pre-eclampsia. The current study provides a baseline for further investigations on the potential role of microbial communities in pre-eclampsia., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Geldenhuys, Redelinghuys, Lombaard, Ehlers, Cowan and Kock.)
- Published
- 2022
- Full Text
- View/download PDF
24. Molecular epidemiology of extended-spectrum beta-lactamase-producing extra-intestinal pathogenic Escherichia coli strains over a 2-year period (2017-2019) from Zimbabwe.
- Author
-
Takawira FT, Pitout JD, Thilliez G, Mashe T, Gutierrez AV, Kingsley RA, Peirano G, Matheu J, Midzi SM, Mwamakamba LW, Gally DL, Tarupiwa A, Mukavhi L, Ehlers MM, Mtapuri-Zinyowera S, and Kock MM
- Abstract
This study was designed to characterize extended-spectrum beta-lactamase (ESBL)-producing extra-intestinal pathogenic Escherichia coli (E.coli) (ExPEC) associated with urinary tract infections in nine different geographic regions of Zimbabwe over a 2-year period (2017-2019). A total of 48 ESBL-positive isolates from urine specimen were selected for whole-genome sequencing from 1246 Escherichia coli isolates biobanked at the National Microbiology Reference laboratory using phenotypic susceptibility testing results from the National Escherichia coli Surveillance Programme to provide representation of different geographical regions and year of isolation. The majority of ESBL E. coli isolates produced cefotaximase-Munich (CTX-M)-15, CTX-M-27, and CTX-M-14. In this study, sequence types (ST) 131 and ST410 were the most predominant antimicrobial-resistant clones and responsible for the increase in ESBL-producing E. coli strains since 2017. Novel ST131 complex strains were recorded during the period 2017 to 2018, thus showing the establishment and evolution of this antimicrobial-resistant ESBL clone in Zimbabwe posing an important public health threat. Incompatibility group F plasmids were predominant among ST131 and ST410 isolates with the following replicons recorded most frequently: F1:A2:B20 (9/19, 47%), F2:A1: B (5/19, 26%), and F1:A1:B49 (8/13, 62%). The results indicate the need for continuous tracking of different ESBL ExPEC clones on a global scale, while targeting specific STs (e.g. ST131 and ST410) through control programs will substantially decrease the spread of ESBLs among ExPEC., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2021
- Full Text
- View/download PDF
25. Lung microbiome of stable and exacerbated COPD patients in Tshwane, South Africa.
- Author
-
Goolam Mahomed T, Peters RPH, Allam M, Ismail A, Mtshali S, Goolam Mahomed A, Ueckermann V, Kock MM, and Ehlers MM
- Subjects
- Aged, Biodiversity, Disease Progression, Female, Humans, Male, Metagenome, Metagenomics, Middle Aged, Risk Factors, South Africa epidemiology, Sputum microbiology, Lung microbiology, Microbiota, Pulmonary Disease, Chronic Obstructive diagnosis, Pulmonary Disease, Chronic Obstructive etiology
- Abstract
Chronic obstructive pulmonary disease (COPD) is characterised by the occurrence of exacerbations triggered by infections. The aim of this study was to determine the composition of the lung microbiome and lung virome in patients with COPD in an African setting and to compare their composition between the stable and exacerbated states. Twenty-four adult COPD patients were recruited from three hospitals. Sputum was collected and bacterial DNA was extracted. Targeted metagenomics was performed to determine the microbiome composition. Viral DNA and RNA were extracted from selected samples followed by cDNA conversion. Shotgun metagenomics sequencing was performed on pooled DNA and RNA. The most abundant phyla across all samples were Firmicutes and Proteobacteria. The following genera were most prevalent: Haemophilus and Streptococcus. There were no considerable differences for alpha and beta diversity measures between the disease states. However, a difference in the abundances between disease states was observed for: (i) Serratia (3% lower abundance in exacerbated state), (ii) Granulicatella (2.2% higher abundance in exacerbated state), (iii) Haemophilus (5.7% higher abundance in exacerbated state) and (iv) Veillonella (2.5% higher abundance in exacerbated state). Virome analysis showed a high abundance of the BeAn 58058 virus, a member of the Poxviridae family, in all six samples (90% to 94%). This study is among the first to report lung microbiome composition in COPD patients from Africa. In this small sample set, no differences in alpha or beta diversity between stable and exacerbated disease state was observed, but an unexpectedly high frequency of BeAn 58058 virus was observed. These observations highlight the need for further research of the lung microbiome of COPD patients in African settings., (© 2021. The Author(s).)
- Published
- 2021
- Full Text
- View/download PDF
26. Evaluation of the rapid ResaPolymyxin Acinetobacter / Pseudomonas NP test for rapid colistin resistance detection in lactose non-fermenting Gram-negative bacteria.
- Author
-
Jung H, Pitout JDD, Mitton BC, Strydom KA, Kingsburgh C, Coetzee J, Ehlers MM, and Kock M
- Subjects
- Acinetobacter baumannii drug effects, Drug Resistance, Multiple, Humans, Indicators and Reagents chemistry, Oxazines chemistry, Polymyxins chemistry, Pseudomonas aeruginosa drug effects, Xanthenes chemistry, Anti-Bacterial Agents pharmacology, Colistin pharmacology, Gram-Negative Bacteria drug effects, Microbial Sensitivity Tests standards
- Abstract
Introduction. Colistin is one of the last-resort antibiotics for treating multidrug-resistant (MDR) or extensively drug-resistant (XDR) lactose non-fermenting Gram-negative bacteria such as Pseudomonas aeruginosa and Acinetobacter baumannii . Gap Statement. As the rate of colistin resistance is steadily rising, there is a need for rapid and accurate antimicrobial susceptibility testing methods for colistin. The Rapid ResaPolymyxin Acinetobacter / Pseudomonas NP test has recently been developed for rapid detection of colistin resistance in P. aeruginosa and A. baumannii . Aim. The present study aimed to evaluate the performance of the Rapid ResaPolymyxin Acinetobacter / Pseudomonas NP test in comparison with the reference broth microdilution (BMD) method. Methodology. The Rapid ResaPolymyxin Acinetobacter / Pseudomonas NP test was performed using a total of 135 P . aeruginosa (17 colistin-resistant and 118 colistin-susceptible) and 66 A. baumannii isolates (32 colistin-resistant and 34 colistin-susceptible), in comparison with the reference BMD method. Results. The categorical agreement of the Rapid ResaPolymyxin Acinetobacter / Pseudomonas NP test with the reference BMD method was 97.5 % with a major error rate of 0 % (0/152) and a very major error (VME) rate of 10.2 %. The VME rate was higher (23.5 %) when calculated separately for P. aeruginosa isolates. The overall sensitivity and specificity were 89.8 and 100 %, respectively. Conclusion. The Rapid ResaPolymyxin Acinetobacter / Pseudomonas NP test performed better for A. baumannii than for P. aeruginosa .
- Published
- 2021
- Full Text
- View/download PDF
27. Erratum Erratum to: Salmonella enterica serovar Typhi H58 clone has been endemic in Zimbabwe from 2012 to 2019.
- Author
-
Mashe T, Leekitcharoenphon P, Mtapuri-Zinyowera S, Kingsley RA, Robertson V, Tarupiwa A, Kock MM, Makombe EP, Chaibva BV, Manangazira P, Phiri I, Nyadundu S, Chigwena CT, Mufoya LP, Thilliez G, Midzi S, Mwamakamba LW, Hamblion EL, Matheu J, Jensen JD, Aarestrup FM, Hendriksen RS, and Ehlers MM
- Published
- 2021
- Full Text
- View/download PDF
28. In vitro antibacterial activity of Loxostylis alata extracts and isolated compounds against Salmonella species.
- Author
-
Gado DA, Abdalla MA, Ahmed AS, Madikizela B, Nkadimeng SM, Ehlers MM, and McGaw LJ
- Subjects
- Anti-Bacterial Agents pharmacology, Humans, Microbial Sensitivity Tests, Phytotherapy, Anacardiaceae, Plant Extracts pharmacology, Salmonella drug effects
- Abstract
Background: Owing to antibiotic resistance, alternative antimicrobials from medicinal plants are receiving attention as leads for anti-infective agents. This study aimed to investigate selected tree species and their constituents for activity against bacterial foodborne pathogens, particularly Salmonella serovars., Methods: Antibacterial activity of ten plant species was determined by serial microdilution against bacteria implicated in causing gastrointestinal ailments. Active compounds were isolated from Loxostylis alata using bioassay-guided fractionation. Antioxidant activity was determined using free-radical scavenging assays. Cytotoxicity and genotoxicity of the extracts was ascertained on Vero cells, and using the Ames assay respectively., Results: Extracts had low to moderate MIC values from 0.04 to 2.5 mg/mL. Protorhus longifolia and Loxostylis alata were most active and L. alata had the highest selectivity index value (2.51) against Salmonella Typhimurium, as well as high antioxidant activity. Cytotoxicity values ranged from 0.02 to 0.47 mg/mL, while tested extracts were not genotoxic. Bioactive compounds isolated from L. alata included delicaflavone and a polymethoxyflavone., Conclusions: The Loxostylis alata leaf extract had strong activity against Salmonella serovars but isolated compounds were less active, indicating likely synergistic effects. Extracts of L. alata are promising candidates for development of antimicrobial preparations or food additives against microbial contamination.
- Published
- 2021
- Full Text
- View/download PDF
29. Salmonella enterica serovar Typhi H58 clone has been endemic in Zimbabwe from 2012 to 2019.
- Author
-
Mashe T, Leekitcharoenphon P, Mtapuri-Zinyowera S, Kingsley RA, Robertson V, Tarupiwa A, Kock MM, Makombe EP, Chaibva BV, Manangazira P, Phiri I, Nyadundu S, Chigwena CT, Mufoya LP, Thilliez G, Midzi S, Mwamakamba LW, Hamblion EL, Matheu J, Jensen JD, Aarestrup FM, Hendriksen RS, and Ehlers MM
- Subjects
- Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Clone Cells, Humans, Microbial Sensitivity Tests, Phylogeny, Zimbabwe epidemiology, Drug Resistance, Multiple, Bacterial genetics, Salmonella typhi genetics
- Abstract
Background: Typhoid fever, caused by S. enterica ser. Typhi, continues to be a substantial health burden in developing countries. Little is known of the genotypic diversity of S. enterica ser. Typhi in Zimbabwe, but this is key for understanding the emergence and spread of this pathogen and devising interventions for its control., Objectives: To report the molecular epidemiology of S. enterica ser. Typhi outbreak strains circulating from 2012 to 2019 in Zimbabwe, using comparative genomics., Methods: A review of typhoid cases records from 2012 to 2019 in Zimbabwe was performed. The phylogenetic relationship of outbreak isolates from 2012 to 2019 and emergence of antibiotic resistance was investigated by whole-genome sequence analysis., Results: A total 22 479 suspected typhoid cases, 760 confirmed cases were reported from 2012 to 2019 and 29 isolates were sequenced. The majority of the sequenced isolates were predicted to confer resistance to aminoglycosides, β-lactams, phenicols, sulphonamides, tetracycline and fluoroquinolones (including qnrS detection). The qnrS1 gene was associated with an IncN (subtype PST3) plasmid in 79% of the isolates. Whole-genome SNP analysis, SNP-based haplotyping and resistance determinant analysis showed that 93% of the isolates belonged to a single clade represented by multidrug-resistant H58 lineage I (4.3.1.1), with a maximum pair-wise distance of 22 SNPs., Conclusions: This study has provided detailed genotypic characterization of the outbreak strain, identified as S. Typhi 4.3.1.1 (H58). The strain has reduced susceptibility to ciprofloxacin due to qnrS carried by an IncN (subtype PST3) plasmid resulting from ongoing evolution to full resistance., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2021
- Full Text
- View/download PDF
30. Klebsiella pneumoniae ST307 with OXA-181: threat of a high-risk clone and promiscuous plasmid in a resource-constrained healthcare setting.
- Author
-
Strydom KA, Chen L, Kock MM, Stoltz AC, Peirano G, Nobrega DB, Lowe M, Ehlers MM, Mbelle NM, Kreiswirth BN, and Pitout JDD
- Subjects
- Bacterial Proteins genetics, Clone Cells, Delivery of Health Care, Humans, Plasmids genetics, South Africa, beta-Lactamases genetics, Klebsiella Infections epidemiology, Klebsiella pneumoniae genetics
- Abstract
Introduction: Klebsiella pneumoniae with OXA-48-like enzymes were introduced into Tshwane Tertiary Hospital (TTH) (Pretoria, South Africa) during September 2015, causing nosocomial outbreaks., Methods: PCR methodologies and WGS were used to characterize K. pneumoniae with carbapenemases (n = 124) from TTH (July 2015-December 2016)., Results: PCR was used to track K. pneumoniae ST307 with OXA-181 among 60% of carbapenemase-positive isolates in different wards/units over time and showed the transmission of IncX3 plasmids to other K. pneumoniae clones. WGS identified different ST307 clades: 307_OXA181 (consisting of two lineages, A and B) with OXA-181 on IncX3 plasmids (named p72_X3_OXA181) and clade 307_VIM with VIM-1 on IncFII plasmids. Clade 307_OXA181 lineage B was responsible for the rapid increase and transmission of OXA-181 K. pneumoniae in various wards/units throughout TTH, while the numbers of clade 307_OXA181 lineage A and clade 307_VIM remained low. Separate outbreaks were due to K. pneumoniae ST17 and ST29 with p72_X3_OXA181 plasmids., Conclusions: The high-risk clone K. pneumoniae ST307 with OXA-181 rapidly spread to different wards/units despite infection and prevention measures. ST307 clades and lineages seemingly acted differently in outbreak situations. This study also highlighted the threat of promiscuous plasmids such as p72_X3_OXA181., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2020
- Full Text
- View/download PDF
31. Growth Forms of Gardnerella spp. and Lactobacillus spp. on Vaginal Cells.
- Author
-
Jung H, Ehlers MM, Peters RPH, Lombaard H, Redelinghuys MJ, Bezuidenhoudt JE, and Kock MM
- Subjects
- Adolescent, Adult, Aged, Biofilms, Female, Gardnerella isolation & purification, HIV Infections complications, Humans, Lactobacillus isolation & purification, Middle Aged, Pregnancy, Pregnancy Complications, Infectious diagnosis, Pregnancy Complications, Infectious microbiology, South Africa epidemiology, Urinary Tract Infections complications, Vagina microbiology, Vaginal Discharge complications, Vaginal Smears, Vaginosis, Bacterial complications, Young Adult, Gardnerella physiology, Lactobacillus physiology, Vaginosis, Bacterial diagnosis, Vaginosis, Bacterial microbiology
- Abstract
Bacterial vaginosis (BV) is a common vaginal condition in women of reproductive age. During BV development, BV-associated bacteria may form a polymicrobial biofilm, which predispose women to recurrent BV. The aim of the study was to investigate the growth forms of Gardnerella spp. and Lactobacillus spp. and to determine the association between the bacterial growth forms and clinical characteristics [urinary tract infection (UTI) symptoms, human immunodeficiency virus (HIV) infection and abnormal vaginal discharge] in women attending a tertiary hospital in Pretoria, South Africa. A first-void urine specimen was collected from 196 women and BV was diagnosed using the Nugent scoring and the Ison-Hay criteria (vaginal smear microscopy). Fluorescence in situ hybridisation (FISH) was performed to classify the growth forms ["dispersed" or "biofilm"]. Bacterial cells were categorized as "dispersed" if cells were scattered separately and as "biofilm" if bacterial aggregates on the vaginal epithelial cells were observed. BV was detected in 52 women (52/196; 27%) and in these women, Gardnerella spp. were predominantly present in biofilms (46/52; 88% for Nugent scoring; and 45/50; 90% for Ison-Hay criteria), whereas Lactobacillus spp. were predominantly present in a dispersed form (38/52; 73% for Nugent scoring; and 37/50; 74% for Ison-Hay criteria). The odds of having BV increased when Gardnerella biofilms were present ( p < 0.001), whereas the opposite was observed for Lactobacillus biofilms ( p = 0.001). Neither Gardnerella spp. or Lactobacillus spp. (both dispersed or biofilms) had an association with the presence of UTI symptoms, HIV coinfection or abnormal vaginal discharge. In conclusion, this study demonstrated and confirmed that Gardnerella biofilms are associated with BV and that Lactobacillus spp. may form biofilms to protect against BV., (Copyright © 2020 Jung, Ehlers, Peters, Lombaard, Redelinghuys, Bezuidenhoudt and Kock.)
- Published
- 2020
- Full Text
- View/download PDF
32. Molecular characteristics and genotypic diversity of enterohaemorrhagic Escherichia coli O157:H7 isolates in Gauteng region, South Africa.
- Author
-
Bolukaoto JY, Kock MM, Strydom KA, Mbelle NM, and Ehlers MM
- Subjects
- Electrophoresis, Gel, Pulsed-Field, Escherichia coli O157 isolation & purification, Multilocus Sequence Typing, South Africa, Escherichia coli O157 genetics, Feces microbiology, Fresh Water microbiology, Genetic Variation, Genotype, Sewage microbiology, Wastewater microbiology
- Abstract
Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 is one of the major foodborne and waterborne pathogens causing severe diseases and outbreaks worldwide. There is scarcity of EHEC O157:H7 data in South Africa. This study was carried out to determine the molecular characteristics and genotypic diversity of EHEC O157:H7 isolates in the Gauteng region, South Africa. Samples were cultured on selective chromogenic media. Antibiotic susceptibility profile of isolates was determined using the VITEK®-2 automated system. Isolates were characterised using multiplex PCR assays and the genetic diversity was determined using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). A total of 520 samples of which 270 environmental water samples and 250 stool specimens were collected and analysed. Overall, EHEC O157:H7 was recovered from 2.3% (12/520) of samples collected. Environmental water samples and clinical stool specimens showed a prevalence of 4.07% (11/270) and 0.4% (1/250) respectively. Antibiotic susceptibility profile varied from isolates with full susceptibility to isolates with resistance to multiple antibiotics. Most resistance was detected to the penicillins, specifically ampicillin (7/12), amoxicillin (3/12) and piperacillin/Tazobactam (3/12) followed by one of the folate inhibitors, trimethoprim (3/12) and the carbapenems, imipenem and meropenem (2/12) each. Three isolates harboured a combination of Shiga-toxins (Stx)-2, intimin (eae) and enterohaemolysin (hlyA) genes, while two isolates harboured the Stx-1, Stx-2 and hlyA genes. The PFGE performed showed that EHEC O157:H7 isolates were genetically diverse, with two minor pulsotypes and eight singletons. The MLST analysis identified three sequence types (STs) (ST10, ST11 and ST1204) that have been previously reported associated with outbreaks. The STs identified in this study pose a potential public health risk to consumers of untreated environmental water and closed human contacts. There is necessity to enhance surveillance in reducing the propagation of this bacterium which is a public health problem., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
33. Klebsiella pneumoniae ST307 with bla OXA-181, South Africa, 2014-2016.
- Author
-
Lowe M, Kock MM, Coetzee J, Hoosien E, Peirano G, Strydom KA, Ehlers MM, Mbelle NM, Shashkina E, Haslam DB, Dhawan P, Donnelly RJ, Chen L, Kreiswirth BN, and Pitout JDD
- Subjects
- Bacterial Proteins genetics, Communicable Diseases, Emerging epidemiology, Communicable Diseases, Emerging genetics, Communicable Diseases, Emerging microbiology, Evolution, Molecular, Genome, Bacterial, Humans, Klebsiella Infections epidemiology, Klebsiella pneumoniae genetics, Molecular Epidemiology, Phylogeny, South Africa epidemiology, Klebsiella Infections microbiology, Klebsiella pneumoniae enzymology, beta-Lactam Resistance genetics, beta-Lactamases genetics
- Abstract
Klebsiella pneumoniae sequence type (ST) 307 is an emerging global antimicrobial drug-resistant clone. We used whole-genome sequencing and PCR to characterize K. pneumoniae ST307 with oxacillinase (OXA) 181 carbapenemase across several private hospitals in South Africa during 2014-2016. The South Africa ST307 belonged to a different clade (clade VI) with unique genomic characteristics when compared with global ST307 (clades I-V). Bayesian evolution analysis showed that clade VI emerged around March 2013 in Gauteng Province, South Africa, and then evolved during 2014 into 2 distinct lineages. K. pneumoniae ST307 clade VI with OXA-181 disseminated over a 15-month period within 42 hospitals in 23 cities across 6 northeastern provinces, affecting 350 patients. The rapid expansion of ST307 was most likely due to intrahospital, interhospital, intercity, and interprovince movements of patients. This study highlights the importance of molecular surveillance for tracking emerging antimicrobial clones.
- Published
- 2019
- Full Text
- View/download PDF
34. Occurrence of enterococci harbouring clinically important antibiotic resistance genes in the aquatic environment in Gauteng, South Africa.
- Author
-
Hamiwe T, Kock MM, Magwira CA, Antiabong JF, and Ehlers MM
- Subjects
- Anti-Bacterial Agents pharmacology, Enterococcus genetics, Hospitals, Microbial Sensitivity Tests, Sewage microbiology, South Africa, Wastewater microbiology, Drug Resistance, Bacterial genetics, Enterococcus isolation & purification, Genes, Bacterial, Water Microbiology standards, Water Purification methods
- Abstract
The development of antibiotic resistance and dissemination of its determinants is an emerging public health problem as it compromises treatment options of infections that were, until recently, treatable. Investigation of outbreaks of vancomycin resistant enterococci (VRE) suggests that the environment serves as a significant reservoir for antibiotic resistance genes (ARGs). However, there is a paucity of data regarding the presence of ARGs in the water sources in South Africa. In this study, water samples collected from wastewater treatment plants (WWTPs), surface water and hospital sewage were screened for enterococci harbouring genes conferring resistance to four classes of antibiotics. Enterococci isolates harbouring ARGs were detected in raw influent and treated wastewater discharge from WWTPs and hospital sewage water. Plasmid and transposon encoded ermB (macrolide), tetM and tetL (tetracycline) as well as aph(3')-IIIa (aminoglycosides) genes were frequently detected among the isolates, especially in E. faecalis. The presence of enterococci harbouring ARGs in the treated wastewater suggest that ARGs are discharged into the environment where their proliferation could be perpetuated. Among the enterococci clonal complexes (CCs) recovered from wastewater were E. faecium CC17 (ST18), which is frequently associated with hospital outbreaks and a novel E. faecalis sequence type (ST), ST780., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
35. Identification and characterization of Staphylococcus devriesei isolates from bovine intramammary infections in KwaZulu-Natal, South Africa.
- Author
-
Schmidt T, Kock MM, and Ehlers MM
- Subjects
- Animals, Cattle, DNA Fingerprinting, Female, Genes, Bacterial genetics, Genes, Essential genetics, Mastitis, Bovine epidemiology, Phylogeny, Sequence Analysis, DNA, South Africa epidemiology, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Staphylococcal Infections epidemiology, Staphylococcal Infections microbiology, Mastitis, Bovine microbiology, Staphylococcal Infections veterinary, Staphylococcus genetics, Staphylococcus isolation & purification
- Abstract
Background: Coagulase-negative staphylococci (CoNS) are among the leading bacterial causes of bovine mastitis in many dairy-producing countries. Among the challenges associated with the specific diagnosis of CoNS infections is the biochemical heterogeneity of the species in the genus and the unavailability of accurate, cost-effective and up-to-date diagnostic tests. A previous study investigating the diversity of CoNS associated with cases of bovine mastitis in South Africa, resulted in six CoNS isolates which could not be identified despite the use of a combination of different molecular assays. The identification and characterisation of the isolates was pursued further in this study., Results: The six CoNS isolates in question were identified by sequencing multiple housekeeping genes (dnaJ, hsp60, rpoB, 16S rRNA) and characterized through the use of matrix-assisted laser/desorption ionization time of flight mass spectrometry (MALDI-TOF MS) and the Biolog GEN III Microplate™ bacterial identification system. Sequencing of housekeeping genes identified the isolates as S. devriesei. This Staphylococcus species was only described in 2010 and this is the first report documenting the isolation of S. devriesei from cases of bovine IMIs in South Africa. Analysis of mass spectra generated by the six isolates showed intra-species variation which was also observed when evaluating the metabolic profiles of the isolates using the Biolog GEN III system. Neither the MALDI-TOF MS nor the Biolog database are currently populated with data relating to S. devriesei, resulting in the isolates not being identified, in the case of MALDI-TOF MS analysis, or mis-identified as was observed with the Biolog GEN III system., Conclusions: The phenotyping data collected during this investigation provides useful information concerning Staphylococcus devriesei which could be used to populate user system databases thereby ensuring the accurate identification of isolates in future. The availability of improved diagnostics will in turn facilitate studies to elucidate the epidemiology, pathogenicity and true prevalence of this species in dairy herds.
- Published
- 2018
- Full Text
- View/download PDF
36. Experiences of Older Adults After Hip Fracture: An Integrative Review.
- Author
-
Ehlers MM, Nielsen CV, and Bjerrum MB
- Subjects
- Aged, Aged, 80 and over, Cost of Illness, Hip Fractures rehabilitation, Humans, Activities of Daily Living psychology, Hip Fractures complications, Quality of Life psychology
- Abstract
Purpose: The aim of the study was to identify and synthesize scientific evidence on older adults' experience after hip fracture in relation to their physical and mental health, functional performance, and participation and to determine which personal or social factors influence functional capacity after hip fracture., Design: Integrative review., Methods: Eleven qualitative or quantitative papers published between 2001 and 2015 were analyzed using integrative review methodology as described by Whittemore and Knafl., Results: Older adults experienced pain and decline in personal and instrumental activities of daily living and used adaptation strategies to cope with the hip fracture., Conclusion: Hip fracture affected the older adults' mobility, body image, mental health, and capacity for participation., Clinical Relevance: Pain measurement tools focusing on various perspectives of health as well as rehabilitation programs focusing on changes in body function and body image and increased awareness of vulnerability in older adults may promote functional capacity after hip fracture.
- Published
- 2018
- Full Text
- View/download PDF
37. Genetic relatedness of Staphylococcus aureus isolates obtained from cystic fibrosis patients at a tertiary academic hospital in Pretoria, South Africa.
- Author
-
Goolam Mahomed T, Kock MM, Masekela R, Hoosien E, and Ehlers MM
- Subjects
- Adolescent, Adult, Bacterial Toxins genetics, Child, Child, Preschool, Electrophoresis, Gel, Pulsed-Field methods, Exotoxins genetics, Female, Genotype, Humans, Infant, Male, Methicillin Resistance drug effects, Methicillin-Resistant Staphylococcus aureus genetics, Microbial Sensitivity Tests, Molecular Epidemiology, Multilocus Sequence Typing methods, South Africa, Staphylococcal Infections microbiology, Tertiary Care Centers, Virulence Factors genetics, Cystic Fibrosis microbiology, Staphylococcus aureus genetics, Staphylococcus aureus pathogenicity
- Abstract
Cystic fibrosis (CF) is an inherited recessive disease that affects mucocillary clearance in the lung, allowing it to be colonised with bacteria such as Staphylococcus aureus. To survive in the CF lung S. aureus adapts both phenotypically and genotypically, through various mechanisms. In this study, multiple specimens were collected from the participants and were processed routinely and were additionally cultured in chromogenic media. Multiplex PCR assays were employed to detect methicillin resistance and selected virulence and quaternary ammonium compound (qac) genes. Genetic relatedness of the S. aureus was determined using agr, SCCmec and spa typing as well as pulsed field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Thirty-three S. aureus isolates were isolated, of which 51% (17/33) were methicillin resistant S. aureus (MRSA). The virulence and qac genes were more prevalent in MRSA than the methicillin sensitive S. aureus (MSSA) isolates. The PFGE analysis showed nine distinct pulsotypes while MLST showed eight sequence types. All the STs detected in this study, except for ST508 have been previously isolated from CF patients according to the literature. This study showed a genetically diverse S. aureus population with a high prevalence of virulence genes among the MRSA isolates from the CF clinic.
- Published
- 2018
- Full Text
- View/download PDF
38. Disruption in the Regulation of Immune Responses in the Placental Subtype of Preeclampsia.
- Author
-
Geldenhuys J, Rossouw TM, Lombaard HA, Ehlers MM, and Kock MM
- Abstract
Preeclampsia is a pregnancy-specific disorder, of which one of its major subtypes, the placental subtype is considered a response to an ischemic placental environment, impacting fetal growth and pregnancy outcome. Inflammatory immune responses have been linked to metabolic and inflammatory disorders as well as reproductive failures. In healthy pregnancy, immune regulatory mechanisms prevent excessive systemic inflammation. However, in preeclampsia, the regulation of immune responses is disrupted as a result of aberrant activation of innate immune cells and imbalanced differentiation of T-helper cell subsets creating a cytotoxic environment in utero . Recognition events that facilitate immune interaction between maternal decidual T cells, NK cells, and cytotrophoblasts are considered an indirect cause of the incomplete remodeling of spiral arteries in preeclampsia. The mechanisms involved include the activation of immune cells and the subsequent secretion of cytokines and placental growth factors affecting trophoblast invasion, angiogenesis, and eventually placentation. In this review, we focus on the role of excessive systemic inflammation as the result of a dysregulated immune system in the development of preeclampsia. These include insufficient control of inflammation, failure of tolerance toward paternal antigens at the fetal-maternal interface, and subsequent over- or insufficient activation of immune mediators. It is also possible that external stimuli, such as bacterial endotoxin, may contribute to the excessive systemic inflammation in preeclampsia by stimulating the release of pro-inflammatory cytokines. In conclusion, a disrupted immune system might be a predisposing factor or result of placental oxidative stress or excessive inflammation in preeclampsia. Preeclampsia can thus be considered a hyperinflammatory state associated with defective regulation of the immune system proposed as a key element in the pathological events of the placental subtype of this disorder.
- Published
- 2018
- Full Text
- View/download PDF
39. Acinetobacter baumannii : Epidemiological and Beta-Lactamase Data From Two Tertiary Academic Hospitals in Tshwane, South Africa.
- Author
-
Lowe M, Ehlers MM, Ismail F, Peirano G, Becker PJ, Pitout JDD, and Kock MM
- Abstract
Acinetobacter baumannii is an opportunistic pathogen that is increasingly responsible for hospital-acquired infections. The increasing prevalence of carbapenem resistant A. baumannii has left clinicians with limited treatment options. Last line antimicrobials (i.e., polymyxins and glycylcyclines) are often used as treatment options. The aim of this study was to determine the prevalence of selected β-lactamase genes from A. baumannii isolates obtained from patients with hospital-acquired infections and to determine the genetic relationship and epidemiological profiles among clinical A. baumannii isolates collected from two tertiary academic hospitals in the Tshwane region, South Africa (SA). Multiplex-PCR (M-PCR) assays were performed to detect selected resistance genes. The collected isolates' genetic relatedness was determined by using pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The acquired oxacillinase (OXA) genes, notably bla
OXA-23-like were prevalent in the A. baumannii isolates. The M-PCR assays showed that the isolates collected from hospital A contained the OXA-23-like (96%; n = 69/72) genes and the isolates collected from hospital B contained the OXA-23-like (91%; n = 63/69) and OXA-58-like (4%; n = 3/69) genes. Colistin resistance was found in 1% of the isolates ( n = 2/141) and tigecycline intermediate resistance was found in 6% of the isolates ( n = 8/141). The A. baumannii isolates were genetically diverse. Molecular epidemiological data showed that specific sequence types (STs) (ST106, ST229, ST258 and ST208) were established in both hospitals, while ST848 was established in hospital A and ST502, ST339 and the novel ST1552 were established in hospital B. ST848 (established in hospital A) was predominately detected in ICU wards whereas ST208, ST339 and the novel ST1552 (established in hospital B) were detected in ICUs and the general wards. The origin of the A. baumannii isolates in the hospitals may be due to the dissemination and adaptation of a diverse group of successful clones. Poor infection control and prevention strategies and possibly the overuse of antimicrobials contributed to the establishment of these A. baumannii clones in the studied hospitals.- Published
- 2018
- Full Text
- View/download PDF
40. Molecular Epidemiology of Staphylococcus epidermidis Implicated in Catheter-Related Bloodstream Infections at an Academic Hospital in Pretoria, South Africa.
- Author
-
Ehlers MM, Strasheim W, Lowe M, Ueckermann V, and Kock MM
- Abstract
Staphylococcus epidermidis is one of the most prevalent pathogens implicated in catheter-related bloodstream infections (CRBSI) at an academic hospital in Pretoria, South Africa. Little is known about the clonality and the prevalence of antibiotic resistance and virulence genes in S. epidermidis (e.g., ica AB, IS 256, mec A, and qac A/B). A total of 508 intravascular catheters (IVCs) from 331 patients were submitted for culture from May to October 2013. Only 50% ( n = 253/508) of the IVCs were accompanied by blood cultures (BCs) taken within 48 h. Forty-four percent (44%; n = 112/253) of IVCs were colonised, of which 26% ( n = 65/253) were associated with a CRBSI. We identified S. epidermidis as the causal agent in 31% ( n = 20/65) of the CRBSI cases. Fifty-nine S. epidermidis isolates were obtained, 23 isolates were cultured from 22 IVCs and 36 isolates were cultured from 36 BCs. All S. epidermidis isolates were resistant to β-lactams (100%; n = 59/59), followed by high levels of resistance toward erythromycin (86%; n = 51/59) and gentamicin (81%; n = 49/59). The mec A gene was prevalent in all the (100%, n = 59/59) isolates. Isolates contained the IS 256 element (83%, n = 49/59), the ica AB gene (81%, n = 48/59) and, the qac A/B gene (81%, n = 48/59). All 48 isolates were qac A positive upon restriction enzyme digestion of the qac A/B amplicons. Phenotypic resistance toward 0.5% (m/v) chlorhexidine was not observed. Staphylococcal Cassette Chromosome (SCC) mec typing showed that SCC mec type IV (31%; n = 18/59) was the most prevalent. The remaining SCC mec elements were highly diverse. Pulsed-field gel electrophoresis (PFGE) showed that S. epidermidis isolates from individual patients were mostly clonal. Multilocus sequencing typing (MLST) of 10 sequenced isolates showed that sequence type (ST) 2 (40%; n = 4/10) was the most frequently detected, followed by ST54 (20%; n = 2/10), ST28 (10%; n = 1/10), ST59 (10%; n = 1/10) and ST490 (10%; 1/10). One isolate was newly assigned to ST596. These S. epidermidis infections can be attributed to patients' skin microflora or to poor infection control practices. Currently, S. epidermidis strains circulating in the studied hospital are multidrug-resistant and highly adaptive to environmental changes.
- Published
- 2018
- Full Text
- View/download PDF
41. Trends in the Genetic Background of Methicillin-Resistant Staphylococcus Aureus Clinical Isolates in a South African Hospital: An Institutional-Based Observational Study.
- Author
-
Antiabong JF, Kock MM, Maphanga TG, Salawu AM, Mbelle NM, and Ehlers MM
- Abstract
Background: This study sought to understand the epidemio-ecological dynamics of MRSA isolates associated with a South African hospital over a period spanning year 2007-8 (a previous study reported in 2009) and year 2010-11 (this study)., Methods: One hundred and ninety three isolates were characterised by molecular fingerprinting methods including pulsed field gel electrophoresis (PFGE), spa typing, agr -typing, SCC mec -typing, and multilocus sequence typing (MLST). The Vitek-2 automated antibiogram of representative isolates was also performed., Results: Our data shows that the distribution of MRSA strains among the different clinical conditions was rarely dependent on the genetic backbone or genotype. Compared to the previous survey in 2009, CA-MRSA isolates increased by 31% while HA-MRSA isolates decreased by 17%. An increase in genetic diversity was also revealed including the detection of three pandemic clonal complexes ( spa type t012-ST36/CC30, spa type t037-ST239/CC8, spa type t891-ST22/CC22 and spa type t1257-ST612/CC8). Majority of the genotypes were classified as Spa Cluster B-SCC mec I- agr I 19.2%; (37/193) Spa Cluster A-SCC mercury - agr I 14.5%; (28/193)., Conclusion: This study reveals that increased diversity in MRSA genetic background was associated with resistance to frontline antibiotics. Also, an increase was recorded in the CA-MRSA/HA-MRSA ratio within a 5-year period despite the continuous dominance of the HA-MRSA genotype.
- Published
- 2017
- Full Text
- View/download PDF
42. Etiology of bacterial vaginosis and polymicrobial biofilm formation.
- Author
-
Jung HS, Ehlers MM, Lombaard H, Redelinghuys MJ, and Kock MM
- Subjects
- Bacterial Adhesion, Female, Humans, Microbiota physiology, Bacteria, Anaerobic growth & development, Bacteria, Anaerobic pathogenicity, Biofilms growth & development, Vagina microbiology, Vaginosis, Bacterial microbiology
- Abstract
Microorganisms in nature rarely exist in a planktonic form, but in the form of biofilms. Biofilms have been identified as the cause of many chronic and persistent infections and have been implicated in the etiology of bacterial vaginosis (BV). Bacterial vaginosis is the most common form of vaginal infection in women of reproductive age. Similar to other biofilm infections, BV biofilms protect the BV-related bacteria against antibiotics and cause recurrent BV. In this review, an overview of BV-related bacteria, conceptual models and the stages involved in the polymicrobial BV biofilm formation will be discussed.
- Published
- 2017
- Full Text
- View/download PDF
43. What are the short-term and long-term effects of occupation-focused and occupation-based occupational therapy in the home on older adults' occupational performance? A systematic review.
- Author
-
Nielsen TL, Petersen KS, Nielsen CV, Strøm J, Ehlers MM, and Bjerrum M
- Subjects
- Adult, Humans, Outcome Assessment, Health Care, Randomized Controlled Trials as Topic, Task Performance and Analysis, Activities of Daily Living, Independent Living, Occupational Therapy methods
- Abstract
Background: There is a lack of evidence-based knowledge about the effectiveness of home-based OT for older adults aimed at improving occupational performance by practicing activities and tasks., Aim: This review synthesizes and discusses evidence for the effectiveness of occupation-focused and occupation-based OT for older adults at home., Material and Methods: Peer-reviewed quantitative papers were included., Participants: ≥ 60-year-old adults with functional limitations., Intervention: OT aiming at improving occupational performance, primarily through the practice of activities and tasks., Outcome: Occupational performance., Context: Home. Three reviewers critically appraised 13 of 995 detected papers. Extracted data were presented and summarized descriptively., Results: Eight high-quality papers showed that occupation-focused and occupation-based OT using cognitive, behavioral and environmental strategies may significantly improve occupational performance in older, home-dwelling adults with physical health problems. Maintaining achieved improvements was a consistent challenge., Conclusions and Significance: Evidence suggests that older adults' occupational performance can be significantly improved through low-intensity occupation-focused and occupation-based intervention. It is recommended to develop and test high-intensity OT programs and maintenance programs.
- Published
- 2017
- Full Text
- View/download PDF
44. Diversity of Multidrug Efflux Genes and Phenotypic Evaluation of the In vitro Resistance Dynamics of Clinical Staphylococcus Aureus Isolates Using Methicillin; a Model β-lactam.
- Author
-
Antiabong JF, Kock MM, Bellea NM, and Ehlers MM
- Abstract
Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) across the world often leave clinicians with little or no choice of treatment options. The multi-drug efflux (MDE) genes are bacterial survival mechanisms responsible for the pumping out of antibiotics and other biocides from the cytoplasm. Whilst effort is being made in the development of antibiotic adjuvants such as efflux pumps inhibitors, information is needed on the diversity of these MDEs in the circulating S. aureus and on the growth dynamics of the clinical isolates in response to antibiotics is not regularly examined., Methods: Here, we evaluated the diversity of MDEs in cinical S. aureus recovered in a tertiary academic hospital, Pretoria, South African hospital using PCR and also employed visual minimum inhibitory concentration and quantitative analysis of spectrophometric measurements of bacterial growth in the presence of a model β lactam antibiotic (methicillin), to phenotypically elucidate the resistance pattern of these isolates in response to methicillin., Results: Three major distribution patterns of MDEs were observed in the clinical isolates evaluated. Moreover, nor A, nor B and tet 38 were present in 98.9% of the isolates while other MDE were present in different proportions ranging from 40 to 98.6% of the isolates. In addition, S. aureus isolates, be it of MRSA or MSSA genotype did not habour the same set of MDEs despite being recovered from the same hospital setting. Finally, we showed that MSSA displayed phenotypic resistance to methicilllin despite the non-detection of the mec A resistance gene., Conclusions: Our data suggest that the growth of S. aureus may be enhanced by β lactams (methicillin) and that MSSA may also display resistance to methicillin and perhaps other β lactam antibiotics. The high prevalence of MDEs suggestive of resistance to a broad spectrum of biocides and fluoroquinolones are particularly disturbing.
- Published
- 2017
- Full Text
- View/download PDF
45. Molecular Characterization of Staphylococcus aureus Isolated from Bovine Mastitis and Close Human Contacts in South African Dairy Herds: Genetic Diversity and Inter-Species Host Transmission.
- Author
-
Schmidt T, Kock MM, and Ehlers MM
- Abstract
Staphylococcus aureus is one of the most common etiological agents of contagious bovine mastitis worldwide. The purpose of this study was to genetically characterize a collection of S. aureus isolates (bovine = 146, human = 12) recovered from cases of bovine mastitis and nasal swabs of close human contacts in the dairy environment. Isolates were screened for a combination of clinically significant antimicrobial and virulence gene markers whilst the molecular epidemiology of these isolates and possible inter-species host transmission was investigated using a combination of genotyping techniques. None of the isolates under evaluation tested positive for methicillin or vancomycin resistance encoding genes. Twenty seven percent of the bovine S. aureus isolates tested positive for one or more of the pyrogenic toxin superantigen (PTSAg) genes with the sec and sell genes predominating. Comparatively, 83% of the human S. aureus isolates tested positive for one or more PTSAg genes with a greater variety of genes being detected. Genomic DNA macrorestriction followed by pulsed-field gel electrophoresis (PFGE) of the bovine isolates generated 58 electrophoretic patterns which grouped into 10 pulsotypes at an 80% similarity level. The majority of the bovine isolates, 93.2% (136/146), clustered into four major pulsotypes. Seven sequence types (ST) were identified among the representative bovine S. aureus isolates genotyped, including: ST8 (CC8), ST97 (CC97), ST351 (CC705), ST352 (CC97), ST508 (CC45), ST2992 (CC97) and a novel sequence type, ST3538 (CC97). Based on PFGE analysis, greater genetic diversity was observed among the human S. aureus isolates. Bovine and human isolates from three sampling sites clustered together and were genotypically indistinguishable. Two of the isolates, ST97 and ST352 belong to the common bovine lineage CC97, and their isolation from close human contacts suggests zoonotic transfer. In the context of this study, the third isolate, ST8 (CC8), is believed to be a human clone which has transferred to a dairy cow and has subsequently caused mastitis. The detection of indistinguishable S. aureus isolates from bovine and human hosts at three of the sampling sites is suggestive of bacterial transmission and supports the need for vigilant monitoring of staphylococcal populations at the human-animal interface.
- Published
- 2017
- Full Text
- View/download PDF
46. Normal flora and bacterial vaginosis in pregnancy: an overview.
- Author
-
Redelinghuys MJ, Ehlers MM, Dreyer AW, and Kock MM
- Subjects
- Bacteria classification, Bacteria genetics, Female, Humans, Microbiota, Pregnancy, Bacteria isolation & purification, Pregnancy Complications microbiology, Vaginosis, Bacterial microbiology
- Abstract
The female genital tract is an intricate, yet balanced ecosystem that hosts a variety of different residential microflora. The physiological changes that occur during pregnancy may disrupt this balanced ecosystem and predispose women to a potentially pathogenic microbiota. Bacteria that are associated with bacterial vaginosis (BV) are opportunistic pathogens that frequently form part of this microbiota. The overgrowth of and infections with these bacteria are linked to poor obstetric outcomes and increased transmission of other reproductive tract infections (RTIs). These infections increase women's susceptibility of acquiring HIV, the rates of HIV shedding and the development of acquired immune deficiency syndrome (AIDS) in HIV-infected patients. It is unknown how the plethora of bacterial species associated with BV contributes to the dynamics of this condition. The use of high-throughput methods have led to the in-depth investigation of different BV-related bacterial species and the functional capabilities of these species. However, the pathogenesis of BV is still poorly defined and the role of individual BV-related bacterial species in specific pregnancy complications is unclear and controversial. The majority of BV infections are asymptomatic and successful diagnosis is complicated by the lack of reliable and standardized diagnostic tests.
- Published
- 2016
- Full Text
- View/download PDF
47. High prevalence of oxacillinases in clinical multidrug-resistant Acinetobacter baumannii isolates from the Tshwane region, South Africa - an update.
- Author
-
Lowings M, Ehlers MM, Dreyer AW, and Kock MM
- Subjects
- Acinetobacter Infections epidemiology, Acinetobacter Infections microbiology, Acinetobacter baumannii genetics, Adolescent, Adult, Aged, Anti-Bacterial Agents therapeutic use, Bacteremia microbiology, Child, Child, Preschool, Colistin pharmacology, Colistin therapeutic use, Electrophoresis, Gel, Pulsed-Field, Humans, Infant, Infant, Newborn, Intensive Care Units, Middle Aged, Multilocus Sequence Typing, Multiplex Polymerase Chain Reaction, South Africa epidemiology, Young Adult, beta-Lactam Resistance genetics, Acinetobacter baumannii drug effects, Acinetobacter baumannii isolation & purification, Anti-Bacterial Agents pharmacology, Drug Resistance, Multiple, Bacterial genetics, beta-Lactamases genetics
- Abstract
Background: Acinetobacter baumannii is an important hospital-acquired pathogen in healthcare facilities that frequently causes bacteraemia and ventilator-associated pneumonia in intensive care units. Acinetobacter baumannii can be isolated from various sites in the hospital environment like medical equipment, bed linen, medical personnel and indwelling catheters. It is difficult to treat A. baumannii infections because of their highly resistant antimicrobial profiles. The purpose of this study was to determine the prevalence of β-lactamase genes in multidrug-resistant (MDR) clinical A. baumannii isolates using Multiplex-PCR (M-PCR) assays., Methods: One hundred MDR A. baumannii isolates were collected from the diagnostic division of the Department of Medical Microbiology after routine analysis of the submitted specimens. All collected isolates were identified and tested for susceptibility using the VITEK 2® system (bioMérieux, France). Six isolates were excluded from this study because the isolates were incorrectly identified as A. baumannii with the VITEK 2® system (bioMérieux, France). Molecular tests, namely M-PCR assays, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were performed. MLST analyses were performed on representative isolates from the four major pulsotypes (≥5 isolates with 80 % similarity) and selective isolates from each minor pulsotype., Results: All the A. baumannii isolates showed 100 % resistance to ampicillin, amoxicillin, cefuroxime, cefuroximine axetil, cefoxitin, cefotaxime and nitrofurantoin. Seven percent of the isolates were resistant to amikacin. Two percent of the isolates were classified as having intermediate susceptibility to tigecycline. A. baumannii isolates showed an antibiotic resistance profile of 67 % and higher to antibiotics, such as ceftazidime, cefepime, imipenem, meropenem, gentamicin, ciprofloxacin and trimethoprim/sulfamethoxazole. None of the isolates were resistant to colistin. The M-PCR assays showed that 99 % of the isolates contained the OXA-51 gene and 77 % contained the OXA-23 gene. None of the isolates contained the GES, GIM, IMP, KPC, NDM, OXA-24, OXA-58, PER, SIM, SPM, VEB and VIM genes. Representative A. baumannii isolates were grouped into five existing sequence types (ST): ST106, ST258, ST339, ST502, ST758 and ST848. Isolates belonging to the pan-European clonal lineages I and II (EUI and EUII) were identified., Conclusion: The high prevalence of MDR A. baumannii isolates has a severe impact on available treatment choices and this in return impacts on treatment outcomes in the studied healthcare facilities. The most dominant ST among the collected isolates was ST758, member of the EUI group. The presence of the OXA-23 gene was not restricted to a specific ST. Continuous research and surveillance is necessary to monitor the circulating β-lactamase genes in clinical settings to guide infection control policies in order to try and curb the spread of this bacterium.
- Published
- 2015
- Full Text
- View/download PDF
48. A cross-sectional study on the relationship of age, gestational age and HIV infection to bacterial vaginosis and genital mycoplasma infection.
- Author
-
Redelinghuys MJ, Ehlers MM, Dreyer AW, Lombaard H, Olorunju SA, and Kock MM
- Subjects
- Adolescent, Adult, Cross-Sectional Studies, Female, Humans, Logistic Models, Multivariate Analysis, Pregnancy, Qualitative Research, Risk Factors, South Africa, Tertiary Care Centers, Vagina microbiology, Young Adult, Age Factors, Gestational Age, HIV Infections epidemiology, Mycoplasma genetics, Mycoplasma Infections epidemiology, Pregnancy Complications diagnosis, Vaginosis, Bacterial epidemiology
- Abstract
Objectives: Pregnant women are especially at risk of developing complications when infected with reproductive tract infections (RTIs). The objective of this study was to determine the prevalence of bacterial vaginosis (BV) and genital mycoplasmas in pregnant women and investigate the associations between BV, genital mycoplasmas, HIV infection, age and gestational age., Design: Cross-sectional study with descriptive and analytical components., Setting: Antenatal clinic of a tertiary academic hospital in South Africa., Participants: 220 pregnant women older than 18 were included in the study and provided self-collected vaginal swabs., Primary and Secondary Outcomes: BV and genital mycoplasma colonisation and/or infection in women of differing age, gestational period and HIV status., Results: The prevalence of BV was 17.7% (39/220) (95% CI 12.9 to 23.4), intermediate vaginal flora (IVF) 15% (33/220) (95% CI 10.56 to 20.42), and the overall prevalence of genital mycoplasmas was 84% (185/220) (95% CI 78.47 to 88.58). BV was significantly associated with HIV infection with an OR of 2.84 (95% CI 1.08 to 7.46 and p value=0.034). However, BV was inversely associated with gestational age with an OR of 0.08 (95% CI 0.01 to 0.42 and p value=0.003) for second trimester pregnancies and an OR of 0.03 (95% CI 0.01 to 0.17 and p value<0.001) for third trimester pregnancies using the first trimester as reference. IVF was significantly associated with HIV infection with an OR of 2.7 (95% CI 1.07 to 6.79 and p value=0.035) but not with age or gestational age. Genital mycoplasmas were not significantly associated with age, gestational age, HIV status, BV flora or IVF., Conclusions: The high infection rate of genital mycoplasmas and the association of BV with HIV found in this study reiterate the importance of screening for these RTIs in high-risk groups such as pregnant women., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)
- Published
- 2015
- Full Text
- View/download PDF
49. Diversity and antimicrobial susceptibility profiling of staphylococci isolated from bovine mastitis cases and close human contacts.
- Author
-
Schmidt T, Kock MM, and Ehlers MM
- Subjects
- Animals, Bacterial Proteins genetics, Biodiversity, Cattle, Female, Humans, Milk microbiology, Penicillin-Binding Proteins genetics, South Africa, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Staphylococcal Infections drug therapy, Staphylococcal Infections veterinary, Staphylococcus classification, Staphylococcus drug effects, Staphylococcus genetics, Staphylococcus aureus isolation & purification, Drug Resistance, Multiple, Bacterial, Genes, Bacterial, Mastitis, Bovine drug therapy, Staphylococcus isolation & purification
- Abstract
The objectives of this study were to examine the diversity of Staphylococcus spp. recovered from bovine intramammary infections and humans working in close contact with the animals and to evaluate the susceptibility of the staphylococcal isolates to different antimicrobials. A total of 3,387 milk samples and 79 human nasal swabs were collected from 13 sampling sites in the KwaZulu-Natal province of South Africa. In total, 146 Staph. aureus isolates and 102 coagulase-negative staphylococci (CNS) were recovered from clinical and subclinical milk samples. Staphylococcusaureus was isolated from 12 (15.2%) of the human nasal swabs and 95 representative CNS were recovered for further characterization. The CNS were identified using multiplex-PCR assays, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and tuf gene sequencing. Seven Staphylococcus spp. were identified among the CNS of bovine origin, with Staph.chromogenes (78.4%) predominating. The predominant CNS species recovered from the human nasal swabs was Staph.epidermidis (80%) followed by Staph.chromogenes (6.3%). The antimicrobial susceptibility of all staphylococcal isolates was evaluated using disk diffusion and was supplemented by screening for specific antimicrobial resistance genes. Ninety-eight (67.1%) Staph.aureus isolates of bovine origin were pansusceptible; 39 (26.7%) isolates were resistant to a single class, and 7 (4.8%) isolates were resistant to 2 classes of antimicrobials. Two Staph. aureus (1.4%) isolates were multidrug-resistant. Resistance to penicillin was common, with 28.8% of the bovine and 75% of the human Staph. aureus isolates exhibiting resistance. A similar observation was made with the CNS, where 37.3% of the bovine and 89.5% of the human isolates were resistant to penicillin. Multidrug-resistance was common among the human CNS, with 39% of the isolates exhibiting resistance to 3 or more classes of antimicrobials. The antimicrobial susceptibility results suggest that resistance among staphylococci causing bovine intramammary infections in South Africa is uncommon and not a significant cause for concern. In contrast, antimicrobial resistance was frequently observed in staphylococcal isolates of human origin, highlighting a possible reservoir of resistance genes. Continued monitoring of staphylococcal isolates is warranted to monitor changes in the susceptibility of isolates to different classes of antimicrobials., (Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
50. Draft Genome Sequences of Five Clinical Methicillin-Resistant Staphylococcus aureus Isolates and a Methicillin-Resistant Staphylococcus epidermidis Isolate.
- Author
-
Biswas RK, Kock MM, Adelowotan T, Strasheim W, Mahomed TG, Salawu A, and Ehlers MM
- Abstract
We report the complete draft genome sequences of five individually isolated strains of methicillin-resistant Staphylococcus aureus (MRSA) and a Staphylococcus epidermidis strain. These clinically important isolates have staphylococcal cassette chromosome mec type A, while Panton-Valentine leukocidin (PVL) toxin coding genes were present in MRSA isolates only., (Copyright © 2015 Biswas et al.)
- Published
- 2015
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.