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This study evaluated the performance of the Xpert Carba-R assay for detecting the five common carbapenemases in carbapenemase-producing organisms in Johannesburg, South Africa between April 2021 and September 2021. The assay demonstrated 98% sensitivity and 97% specificity. It was also able to detect all the carbapenemases in double carbapenemase producers, as well as carbapenemases in non-fermenter organisms. The Xpert Carba-R assay, therefore, allows the rapid (< 1 h) and accurate identification of the common carbapenemases in pure bacterial cultures and rectal swabs. This assay can aid in the timeous institution of appropriate treatment and infection prevention and control measures. [ABSTRACT FROM AUTHOR]

Background: Correctional centres provide ideal conditions for tuberculosis (TB) transmission and disease progression. Despite the high TB incidence and incarceration rate in South Africa, data from South African correctional centres are scarce. Thus, the study evaluated TB diagnosis, treatment initiation and completion, and identified prevalent Mycobacterium tuberculosis strains among detainees entering a South African correctional centre. Methods: This study was a prospective observational study that enrolled participants between February and September 2017 from a correctional centre located in the Western Cape, South Africa. All adult male detainees who tested positive for TB during admission screening were eligible to participate in the study. Sputum samples from enrolled participants underwent smear microscopy and culture. Strain typing was performed on culture-positive samples. The time between specimen collection and diagnosis, the time between diagnosis and treatment initiation, and the proportion of detainees completing TB treatment at the correctional centre were calculated. Results: During the study period, 130 TB cases were detected through routine admission screening (126 male, 2 female, 2 juvenile). Out of the 126 eligible male detainees, 102 were enrolled in the study (81%, 102/126). All TB cases were detected within 30 hrs of admission screening. The majority (78%, 80/102) of participants started treatment within 48 hrs of TB diagnosis. However, only 8% (9/102) of participants completed treatment at the correction centre. Sputa from 90 of the 102 participants were available for smear and culture. There was a high smear positivity, with 49% (44/90) of isolates being smear positive. The Beijing family was the most frequent lineage (55.2%) in the study. Conclusion: The strengths of the current TB control efforts at the correctional centre include rapid detection of cases through admission screening and prompt treatment initiation. However, a high number of detainees exiting before treatment completion highlights the need to strengthen links between correctional TB services and community TB services to ensure detainees complete TB treatment after release and prevent TB transmission. [ABSTRACT FROM AUTHOR]

Background: The 2017–2018 listeriosis outbreak in South Africa warranted testing for Listeria monocytogenes in food products and processing environments. Diagnostic tests are needed to accurately differentiate L. monocytogenes from other Listeria species. Objective: The study assessed the performance of the commonly used tests in our setting to accurately identify L. monocytogenes. Methods: The study was conducted in a public health laboratory in South Africa. Cultured isolates from food and environmental samples were tested both prospectively and retrospectively between August 2018 and December 2018. Isolates were phenotypically identified using tests for detecting β-haemolysis, Christie-Atkins-Munch-Peterson, alanine arylamidase (AlaA), mannosidase, and xylose fermentation. Listeria monocytogenes isolates were identified using automated systems, Microscan Walkaway Plus 96, Vitek® MS, Vitek® 2 and Surefast Listeria monocytogenes PLUS PCR. All results were compared to whole-genome sequencing results. Results: β-haemolysis and Christie-Atkins-Munch-Peterson tests gave delayed positivity or were negative for L. monocytogenes and falsely positive for one strain of Listeria innocua. The AlaA enzyme and Colorex Listeria agar lacked specificity for L. monocytogenes identification. Based on a few phenotypic test results, an aberrant L. monocytogenes strain and Listeria seeligeri strain were reported. All automated platforms overcalled L. monocytogenes in place of other Listeria species. Conclusion: No test was ideal in differentiating Listeria species. This is an issue in resource-limited settings where these tests are currently used. Newer technologies based on enzyme-linked immunosorbent assay and other molecular techniques specific to L. monocytogenes detection need to be investigated. [ABSTRACT FROM AUTHOR]

Introduction: Antimicrobial resistant bacterial infections are widespread globally and increases in antimicrobial resistance presents a major threat to public health. Pseudomonas aeruginosa is an opportunistic healthcare-associated pathogen with high rates of morbidity and mortality and an extensive range of resistance mechanisms. This study describes the antibiotic susceptibility profiles of P. aeruginosa isolates from patients with bacteraemia submitted by sentinel laboratories in South Africa from 2014 to 2015. Methodology: Organism identification and antimicrobial susceptibility testing were done using automated systems. Molecular methods were used to detect common resistance genes and mechanisms. Methodology: Organism identification and antimicrobial susceptibility testing were done using automated systems. Molecular methods were used to detect common resistance genes and mechanisms. Results: Overall the susceptibility was high for all antibiotics tested with a decrease over the two-year period. There was no change in the MIC50 and MIC90 breakpoints for all antibiotics from 2014 to 2015. The MIC50 was within the susceptible breakpoint range for most antibiotics and the MIC90 was within the susceptible breakpoint range for colistin only. Phenotypically carbapenem non-susceptible isolates harboured the following plasmid-mediated genes: blaVIM (n = 81, 12%) and blaGES (n = 6, 0.9%); blaNDM (n = 4, 0.6%) and blaOXA-48 and variants (n = 3, 0.45%). Porin deletions were observed in one meropenem non-susceptible isolate only, and multi-drug resistance efflux pumps were expressed in the majority of the non-susceptible isolates investigated. BlaVEB-1, blaIMP and blaKPC were not detected. Conclusion: The prevalence of resistance to commonly used antibacterial agents was low for P. aeruginosa isolates and similarly, tested resistance mechanisms were detected in a relatively small proportion of isolates. Findings in this study represent baseline information for understanding antimicrobial susceptibility patterns in P. aeruginosa isolates from blood. Our surveillance report may assist in contributing to hospital treatment guidelines. [ABSTRACT FROM AUTHOR]

A nosocomial outbreak of disease involving 5 patients, 4 of whom died, occurred in South Africa during September-October 2008. The first patient had been transferred from Zambia to South Africa for medical management. Three cases involved secondary spread of infection from the first patient, and 1 was a tertiary infection. A novel arenavirus was identified. The source of the first patient's infection remains undetermined. [ABSTRACT FROM AUTHOR]

Retrospective antibiotic surveillance data of selected invasive pathogens isolated from blood and cerebrospinal fluid at public sector hospitals in South Africa in 2007 are presented. Antimicrobial susceptibilities were determined according to the 2007 Clinical and Laboratory Standards Institute criteria. Klebsiella pneumoniae remains a highly resistant pathogen, with approximately half of all strains producing extended-spectrum beta-lactamases. All laboratories reported considerable resistance among Acinetobacter spp. Approximately 50-60% of Staphylococcus aureus isolates from blood were resistant to cloxacillin. Among Streptococcus pneumoniae isolates from blood and cerebrospinal fluid, resistance to penicillin ranged from 0% to 6% at most laboratories and 16-42% of isolates were classified with intermediate resistance to penicillin. Resistance to ceftriaxone in S. pneumoniae was rare. [ABSTRACT FROM AUTHOR]

The Global Action Plan on antimicrobial resistance calls for the use of antimicrobial medicines in human and animal health to be optimized, in tandem with a strengthening of the knowledge and evidence base through surveillance and research. However, there is a paucity of consumption data for African countries such as South Africa. Determining antimicrobial consumption data in low-resource settings remains a challenge. This article describes alternative mechanisms of assessing antimicrobial consumption data, such as the use of Intercontinental Marketing Services (IMS) data and contract data arising from tenders (an open Request for Proposal, RFP), as opposed to the international norms of daily defined doses per 100 patient-days or per 1000 population. Despite their limitations, these serve as indicators of antimicrobial exposure at the population level and represent an alternative method for ascertaining antimicrobial consumption in human health. Furthermore, South Africa has the largest antiretroviral treatment programme globally and carries a high burden of tuberculosis. This prompted the inclusion of antiretroviral and anti-tuberculosis antibiotic consumption data. Knowledge of antimicrobial utilization is imperative for meaningful future interventions. Baseline antimicrobial utilization data could guide future research initiatives that could provide a better understanding of the different measures of antibiotic use and the level of antibiotic resistance. [ABSTRACT FROM AUTHOR]

Most investigations into the distribution of methicillin resistant Staphylococcus aureus (MRSA) have focused exclusively on bloodborne infections within individual health care institutions for shorter time periods. This has limited the analysis of a community-spread pathogen to snapshots within the hospital domain. Therefore, in this study we determined the demographic and geographical patterns of MRSA infections and their fluctuation in 10 years within all public hospitals in Gauteng, South Africa. A retrospective analysis of S. aureus samples was done by deduplicating samples in two groups. The sample groups were placed into subsets with respect to demographic and geographical fields and compared across the studied period. Logistic regression was utilized to determine odds ratios for resistant infections in univariate and multivariable configurations. A total of 66,071 unique infectious events were identified from the 148,065 samples received over a 10-year period, out of which 14,356 were identified as bacteremia. MRSA bacteremia rates in Gauteng peaked in 2015 and have since decreased. Within Gauteng, metropolitan areas have the greatest burden of MRSA with children under 5 years of age and males being most affected. Medical wards have the highest S. aureus bacteremia rates, while intensive care units have the highest MRSA bacteremia rates. Patient age, admitting ward, and geographical district are the most important associated factors of resistance. MRSA acquisition rates have shown tremendous growth since 2009 but have since spiked and subsequently decreased. This may be due to the initiation of the National Guidelines on Antimicrobial Stewardship and Infectious Disease Surveillance. Further studies to determine the trajectory of infections are required to support these claims. IMPORTANCE S. aureus is the leading cause of a variety of devastating clinical conditions, including infective endocarditis, bacteremia, and pleuropulmonary infections. It is an important pathogen responsible for substantial morbidity and mortality. MRSA is a variant of interest originally responsible for difficult to treat hospital-acquired infections that has since achieved community spread throughout the world. Most investigations into the distribution of MRSA have focused exclusively on bloodborne infections within individual health care institutions for shorter periods. This has limited the analysis of a community-spread pathogen to snapshots within the hospital domain. This study sought to determine the demographic and geographical patterns of MRSA infections as well as how these have fluctuated over time within all public hospitals. This will also help in understanding the epidemiology and resistance trends of S. aureus, which will help clinicians to understand the clinical prospective and policy makers to design guidelines and strategies for treating such infections., Competing Interests: The authors declare no conflict of interest.

Objectives: In this study, we examined the impact of epigenetic modifications on host gene functioning by assessing the expression of seven candidate genes in three separate groups including healthy, multidrug-resistant (MDR) TB-HIV co-infected and HIV-1 positive individuals., Methods: Ten patients with MDR TB and HIV-1 co-infection on TB and HIV therapy and a cohort comprised of 10 newly diagnosed individuals with HIV-1 infection were recruited from the TB and HIV clinics at the Charlotte Maxeke Johannesburg Academic Hospital. Notably, the HIV-1 positive individuals were not placed on antiretroviral therapy (ART) at the time of recruitment and blood collection. A third group consisting of 10 healthy participants without MDR TB or HIV infection was recruited from the University of the Witwatersrand. Blood samples collected from all three cohorts were employed for extraction of plasma, total RNA and genomic DNA., Results: Our data indicated that the expression of DNA methyltransferase 1 (DNMT1) and Ten-eleven translocation methylcytosine dioxygenase 1 (TET1) genes was significantly increased in HIV-1 positive patients and was lowest in MDR TB-HIV co-infected patients. By contrast, histone acetyltransferase (HAT), histone deacetylase (HDAC), protein tyrosine kinase (PtkA) and protein tyrosine phosphatase (PtpA) mRNA expression levels were substantially enhanced in HIV-1 infected and were lowest in healthy individuals. Conversely, Dicer expression levels were comparable among all three study groups., Conclusion: Promising preliminary data emanating from this investigation may potentially be used for generation of novel vaccines and therapeutic compounds capable of neutralising MDR TB-HIV and HIV-1 infection., (Copyright © 2020. Published by Elsevier Ltd.)

Background: An outbreak of listeriosis was identified in South Africa in 2017. The source was unknown., Methods: We conducted epidemiologic, trace-back, and environmental investigations and used whole-genome sequencing to type Listeria monocytogenes isolates. A case was defined as laboratory-confirmed L. monocytogenes infection during the period from June 11, 2017, to April 7, 2018., Results: A total of 937 cases were identified, of which 465 (50%) were associated with pregnancy; 406 of the pregnancy-associated cases (87%) occurred in neonates. Of the 937 cases, 229 (24%) occurred in patients 15 to 49 years of age (excluding those who were pregnant). Among the patients in whom human immunodeficiency virus (HIV) status was known, 38% of those with pregnancy-associated cases (77 of 204) and 46% of the remaining patients (97 of 211) were infected with HIV. Among 728 patients with a known outcome, 193 (27%) died. Clinical isolates from 609 patients were sequenced, and 567 (93%) were identified as sequence type 6 (ST6). In a case-control analysis, patients with ST6 infections were more likely to have eaten polony (a ready-to-eat processed meat) than those with non-ST6 infections (odds ratio, 8.55; 95% confidence interval, 1.66 to 43.35). Polony and environmental samples also yielded ST6 isolates, which, together with the isolates from the patients, belonged to the same core-genome multilocus sequence typing cluster with no more than 4 allelic differences; these findings showed that polony produced at a single facility was the outbreak source. A recall of ready-to-eat processed meat products from this facility was associated with a rapid decline in the incidence of L. monocytogenes ST6 infections., Conclusions: This investigation showed that in a middle-income country with a high prevalence of HIV infection, L. monocytogenes caused disproportionate illness among pregnant girls and women and HIV-infected persons. Whole-genome sequencing facilitated the detection of the outbreak and guided the trace-back investigations that led to the identification of the source., (Copyright © 2020 Massachusetts Medical Society.)

Introduction: We aimed to obtain an in-depth understanding on recent antimicrobial resistance trends and molecular epidemiology trends of S. aureus bacteraemia (SAB)., Methods: Thirteen academic centres in South Africa were included from June 2010 until July 2012. S. aureus susceptibility testing was performed on the MicroScan Walkaway. Real-time PCR using the LightCycler 480 II was done for mecA and nuc. SCCmec and spa-typing were finalized with conventional PCR. We selected one isolate per common spa type per province for multilocus sequence typing (MLST)., Results: S. aureus from 2709 patients were included, and 1231 (46%) were resistant to methicillin, with a significant decline over the three-year period (p-value = 0.003). Geographical distribution of MRSA was significantly higher in Gauteng compared to the other provinces (P<0.001). Children <5 years were significantly associated with MRSA with higher rates compared to all other age groups (P = 0.01). The most prevalent SCCmec type was SCCmec type III (531 [41%]) followed by type IV (402 [31%]). Spa-typing discovered 47 different spa-types. The five (87%) most common spa-types were t037, t1257, t045, t064 and t012. Based on MLST, the commonest was ST612 clonal complex (CC8) (n = 7) followed by ST5 (CC5) (n = 4), ST36 (CC30) (n = 4) and ST239 (CC8) (n = 3)., Conclusions: MRSA rate is high in South Africa. Majority of the isolates were classified as SCCmec type III (41%) and type IV (31%), which are typically associated with hospital and community- acquired infections, respectively. Overall, this study reveals the presence of a variety of hospital-acquired MRSA clones in South Africa dominance of few clones, spa 037 and 1257. Monitoring trends in resistance and molecular typing is recommended to detect changing epidemiological trends in AMR patterns of SAB.

Mycobacterium kansasii (M. kansasii) is a major cause of non-tuberculous mycobacterial pulmonary disease in the South African gold-mining workforce, but the source of infection and molecular epidemiology are unknown. This study investigated the presence of M. kansasii in gold and coal mine and associated hostel water supplies and compared the genetic diversity of clinical and environmental isolates of M. kansasii. Five M. kansasii and ten other potentially pathogenic mycobacteria were cultured mainly from showerhead biofilms. Polymerase chain reaction-restriction analysis of the hsp65 gene on 196 clinical and environmental M. kansasii isolates revealed 160 subtype I, eight subtype II and six subtype IV strains. Twenty-two isolates did not show the typical M. kansasii restriction patterns, suggesting that these isolates may represent new subtypes of M. kansasii. In contrast to the clonal population structure found amongst the subtype I isolates from studies in other countries, DNA fingerprinting of 114 clinical and three environmental subtype I isolates demonstrated genetic diversity amongst the isolates. This study demonstrated that showerheads are possible sources of M. kansasii and other pathogenic non-tuberculous mycobacterial infection in a gold-mining region, that subtype I is the major clinical isolate of M. kansasii strain and that this subtype exhibits genetic diversity.

South Africa implemented Xpert MTB/RIF as the initial diagnostic test for pulmonary tuberculosis (TB). Xpert MTB/RIF's accuracy for diagnosing extrapulmonary tuberculosis (EPTB) was investigated. EPTB specimens (n = 7,916) from hospitalized patients received over a 6-month period at a high-throughput TB referral laboratory in Johannesburg were investigated. Large-volume specimens were centrifuged, tissue biopsy specimens homogenized, and all specimens checked for growth of contaminating bacteria on blood agar. Contaminated samples received NALC-NaOH (N-acetyl-l-cysteine-sodium hydroxide) decontamination prior to liquid culture. Residual specimens (volumes > 1 ml) after inoculation of culture (n = 1,175) were tested using the Xpert MTB/RIF sputum protocol. Using culture as the reference, Xpert MTB/RIF's overall sensitivity was 59% (95% confidence interval [95% CI], 53% to 65%) and specificity was 92% (CI, 90% to 94%), with the highest sensitivities of 91% (95% CI, 78% to 97%) for pus, 80% (95% CI, 56% to 94%) for lymph node aspirates, and 51% (95% CI, 44% to 58%) for fluids (ascitic, 59%; pleural, 47%). A difference in sensitivities was noticed between specimens classified as having a thick (87% [95% CI, 76% to 94%]) versus clear (watery) (48% [95% CI, 36% to 61%]) appearance. This was unchanged with traces of blood (52% [95% CI, 44% to 60%]) or precentrifugation (57% [95% CI, 28% to 82%]) among clear specimens. Xpert MTB/RIF generated an additional 124 specimen results that were contaminated by Mycobacterial Growth Indicator Tubes (MGIT; 10.5%) and diagnosed rifampin (RIF) resistance earlier (9.6% [25/260]). Xpert MTB/RIF's performance on EPTB specimens provides very promising results and should be considered for incorporation into national TB guidelines. Xpert MTB/RIF is less affected by contaminating bacteria and reduces laboratory labor and diagnostic delay compared to traditional methods., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

Numerous reports have documented isolated transmission events or clonal outbreaks of multidrug-resistant Mycobacterium tuberculosis strains, but knowledge of their epidemic spread remains limited. In this study, we evaluated drug resistance, strain diversity, and clustering rates in patients diagnosed with multidrug-resistant (MDR) tuberculosis (TB) at the National Health Laboratory Service (NHLS) Central TB Laboratory in Johannesburg, South Africa, between March 2004 and December 2007. Phenotypic drug susceptibility testing was done using the indirect proportion method, while each isolate was genotyped using a combination of spoligotyping and 12-MIRU typing (12-locus multiple interspersed repetitive unit typing). Isolates from 434 MDR-TB patients were evaluated, of which 238 (54.8%) were resistant to four first-line drugs (isoniazid, rifampin, ethambutol, and streptomycin). Spoligotyping identified 56 different strains and 28 clusters of variable size (2 to 71 cases per cluster) with a clustering rate of 87.1%. Ten clusters included 337 (77.6%) of all cases, with strains of the Beijing genotype being most prevalent (16.4%). Combined analysis of spoligotyping and 12-MIRU typing increased the discriminatory power (Hunter Gaston discriminatory index [HGDI] = 0.962) and reduced the clustering rate to 66.8%. Resolution of Beijing genotype strains was further enhanced with the 24-MIRU-VNTR (variable-number tandem repeat) typing method by identifying 15 subclusters and 19 unique strains from twelve 12-MIRU clusters. High levels of clustering among a variety of strains suggest a true epidemic spread of MDR-TB in the study setting, emphasizing the urgency of early diagnosis and effective treatment to reduce transmission within this community.

Objective: To write a guideline for the management and prevention of nosocomial infections in South Africa in view of the following: Nosocomial infections are a common and increasing problem globally, including South Africa. Widely varying standards of prevention and management of these important infections. Increasing and emerging antimicrobial resistance among commonly isolated pathogens. The significant economic burden of these infections on the health care system as well as their impact on patient morbidity and mortality. The main aims of the guideline are to provide recommendations for the initial choice of antimicrobial agents and the appropriate management of these infections encompassing the following conditions: (i) nosocomial pneumonia, health care-associated pneumonia and ventilator-associated pneumonia; (ii) nosocomial bloodstream infections; (iii) nosocomial intravascular infections; (iv) nosocomial urinary tract infections; (v) nosocomial intra-abdominal infections; and (vi) nosocomial surgical skin and soft-tissue infections., Evidence: Working group of clinicians from relevant disciplines, following detailed literature review., Recommendations: These include details of the likely pathogens, an appropriate diagnostic approach, antibiotic treatment options and appropriate preventive strategies., Endorsement: The guideline document was endorsed by the South African Thoracic Society, the Critical Care Society of Southern Africa and the Federation of Infectious Diseases Societies of Southern Africa.