37 results on '"Sonda, T."'
Search Results
2. Relevance Analysis of keywords related to Sustainability
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Masui, K., Sonda, T., Seliger, Günther, editor, Khraisheh, Marwan M.K., editor, and Jawahir, I.S., editor
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- 2011
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3. Utilization of Polysaccharides Extracted from Tofu Processing Wastewater for Microencapsulation Processes in the Food Industry
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Sonda, T. S., primary, Sawi, Memuna K., primary, Nyamawa, Abigail, primary, and Sonda, M. S., primary
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- 2022
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4. Multicentre trial of ABO-incompatible kidney transplantation
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Ota, K., Takahashi, K., Agishi, T., Sonda, T., Oka, T., Ueda, S., Amemiya, H., Shiramizu, T., Okazaki, H., Akiyama, N., Hasegawa, A., Kawamura, T., Takagi, H., Ueno, A., Kootstra, Gauke, editor, Opelz, Gerhard, editor, Buurman, W. A., editor, van Hooff, J. P., editor, MacMaster, P., editor, and Wallwork, J., editor
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- 1992
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5. Meta-analysis of proportion estimates of extended-spectrum-beta-lactamase-producing Enterobacteriaceae in East Africa hospitals
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Sonda, T., Kumburu, H., van Zwetselaar, M., Alifrangis, M., Lund, O., Kibiki, G., Aarestrup, M. Frank F., Sonda, T., Kumburu, H., van Zwetselaar, M., Alifrangis, M., Lund, O., Kibiki, G., and Aarestrup, M. Frank F.
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- 2017
6. Prevalence and risk factors of CTX-M Enterobacteriaceae in hospitalised patients at a tertiary hospital in Kilimanjaro, Tanzania
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Sonda, T., Kumburu, H., van Zwetselaar, M., Alifrangis, M., Mmbaga, B., Lund, O., Aarestrup, F., Kibiki, G., Sonda, T., Kumburu, H., van Zwetselaar, M., Alifrangis, M., Mmbaga, B., Lund, O., Aarestrup, F., and Kibiki, G.
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- 2017
7. Patterns of infections, aetiological agents, and antimicrobial resistance at a tertiary care hospital in northern Tanzania
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Kumburu, H. H., Sonda, T., Mmbaga, B. T., Alifrangis, M., Lund, O., Kibiki, G., Aarestrup, F. M., Kumburu, H. H., Sonda, T., Mmbaga, B. T., Alifrangis, M., Lund, O., Kibiki, G., and Aarestrup, F. M.
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- 2017
8. Hospital epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in a tertiary care hospital in Moshi Tanzania as determined by whole genome sequencing
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Kumburu, H. H., Sonda, T., Leetcharoenphon, P., van Zwetselaar, M., Lukjancenko, O., Alifrangis, M., Lund, O., Mmbaga, B. T., Kibiki, G., Aarestrup, F. M., Kumburu, H. H., Sonda, T., Leetcharoenphon, P., van Zwetselaar, M., Lukjancenko, O., Alifrangis, M., Lund, O., Mmbaga, B. T., Kibiki, G., and Aarestrup, F. M.
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- 2017
9. Expert and Novice Users Model and their Application to the Design Process
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Kubo, M, Sonda, T, Iwanaga, K, Yamanaka, T, Terauchi, F, Kiritani, Y, Miyazawa, K, Nagamori, Y, Tamagaiki, Y, Kobayakawa, M, Popovic, Vesna, Kubo, M, Sonda, T, Iwanaga, K, Yamanaka, T, Terauchi, F, Kiritani, Y, Miyazawa, K, Nagamori, Y, Tamagaiki, Y, Kobayakawa, M, and Popovic, Vesna
- Abstract
This research was undertaken to provide the designers of interactive artifacts with more knowledge about the human users of these artifacts, and a better understanding of how they use them. Therefore the research explored differences and similarities between novice and expert users of interactive artifacts. In order to achieve this, protocol analysis was used to identify users’ cognitive categories, knowledge categories and knowledge representation. Based on the taxonomy proposed and differences identified, each cognitive category was modelled. The models are designed on the premises that knowledge — domain-specific knowledge in particular — plays a significant role in distinguishing a novice from an expert user, and the way in which they use technologically interactive devices. They also constitute the features that reflect the kind of processes, representations, strategies or knowledge organisation that may occur for each cognitive category during the interaction. The models contribute to the better understanding of the differences between the novice and expert users while they interact with artifacts. Their potential applications are: (a) as designers’ computer support tool to understand better the users of the artifact they design; (b) in design research in order to get better understanding how designers work; (c) for artifact useability assessment; (d) in education and design education in particular and (d) for different training procedures. This paper will explore the model applications to the design process. It will attempt to clarify how) the users’ model should be included in the design process.
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- 2003
10. Hospital epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in a tertiary care hospital in Moshi Tanzania as determined by whole genome sequencing
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Kumburu, H. H., Sonda, T., Leetcharoenphon, P., Zwetselaar, M., Oksana Lukjancenko, Alifrangis, M., Ole Lund, Mmbaga, B. T., Kibiki, G., and Frank Aarestrup
11. Whole genome sequencing-based characterization and determination of quinolone resistance among methicillin-resistant and methicillin-susceptible S. Aureus isolates from patients attending regional referral hospitals in Tanzania.
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Juma MA, Kumburu H, Wadugu B, Kuchaka D, Shayo M, Kimu P, Kanje LE, Beti M, van Zwetselaar M, Mmbaga B, and Sonda T
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- Tanzania, Humans, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Microbial Sensitivity Tests, Cross-Sectional Studies, Staphylococcus aureus genetics, Staphylococcus aureus drug effects, Staphylococcus aureus isolation & purification, Multilocus Sequence Typing, Drug Resistance, Bacterial genetics, Methicillin-Resistant Staphylococcus aureus genetics, Methicillin-Resistant Staphylococcus aureus drug effects, Methicillin-Resistant Staphylococcus aureus isolation & purification, Quinolones pharmacology, Whole Genome Sequencing methods, Staphylococcal Infections microbiology, Staphylococcal Infections drug therapy, Phylogeny
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Background: The emergence of multidrug-resistant termed Methicillin-resistant Staphylococcus aureus (MRSA) strain, driven by the acquisition of resistance gene mecA imposes a substantial challenge in the treatment and control of their related infections. Although quinolones have historically been effective against both MRSA and methicillin-susceptible S. aureus (MSSA) strains, the rising resistance to quinolones among S. aureus isolates, particularly in MRSA, has severely curtailed their potency and further narrowed down the therapeutic options. This study aimed to determine the burden of MRSA among isolates, as well as their resistance profile, genotypic characterization, and molecular relatedness through the construction of a phylogenetic tree., Materials and Methods: Archived clinical S. aureus isolates from a descriptive, cross-sectional study involving six regional referral hospitals in Dodoma, Songea, Kigoma, Kitete, and Morogoro in the mainland Tanzania and Mnazi Mmoja in Zanzibar were analyzed. Bacterial identification was performed using both classical microbiology and whole genome sequencing on Illumina Nextseq 550 Sequencer. Species identification was done using KmerFinder 3.2, Multilocus Sequence Typing using MLST 2.0, SCCmec typing using SCCmecFinder 1.2, resistance genes using ResFinder 4.1, and phylogenetic relatedness using CSI Phylogeny 1.4., Results: Out of the 140 isolates analyzed, 69 (49.3%) were identified as MRSA, with 57 (82.6%) exhibiting quinolone resistance. Conversely, 71 isolates were identified as MSSA, and none of them exhibited resistance to quinolones. Spa-typing revealed six spa types, with t355, t1476, and t498 being the most common. Moreover, all (69) MRSA were found to carry SCCmec type IV. The isolates exhibited 14 different sequence types (STs). Notably, ST152 was prevalent among MSSA (50 isolates, 70%), while ST8 was the predominant sequence type among MRSA (58 isolates, 84%). The antimicrobial resistance profile revealed at least three horizontally acquired resistance genes, with blaZ, dfrG, tet(K), and aac (6')-aph (2'') genes being highly prevalent., Conclusion: There is a high genetic diversity among the S. aureus isolates existing in Tanzania regional hospitals, with a concerning burden of quinolone resistance among MRSA isolates. The diversity in resistance genes among MRSA lineages emphasizes the necessity for the development of sustainable antimicrobial stewardship and surveillance to support evidence-based guidelines for managing and controlling MRSA infections in both community and hospital settings., Competing Interests: Declarations. Ethics approval and consent to participate: The ethical clearance to conduct was sought from the Kilimanjaro Christian Medical University College (KCMUCo) Research Ethics and Review Committee and the ethical clearance with certificate number PG.171/2023 was given. Permission to access the Biotech laboratory and the archived samples was granted by the KCRI administration. The parent study secured its ethical clearance from NIMR Tanzania with reference number NIMR/HQ/R.8a/Vol.IX/3273. Informed consent was obtained from all participants or their legal guardians before the use of their samples for research purposes. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)
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- 2024
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12. Whole genome-based antimicrobial resistance and virulence profiling of Staphylococcus aureus isolates from chronic leg ulcer patients in Kilimanjaro, Tanzania.
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Omar OS, Sengeruan LP, Kanje LE, van Zwetselaar M, Kuchaka DJ, Shayo MJ, Kumburu H, Sonda T, Mshana J, and Chugulu S
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- Humans, Tanzania, Male, Female, Virulence genetics, Middle Aged, Cross-Sectional Studies, Adult, Drug Resistance, Bacterial genetics, Microbial Sensitivity Tests, Chronic Disease, Aged, Genome, Bacterial, Staphylococcal Infections microbiology, Staphylococcal Infections drug therapy, Staphylococcal Infections epidemiology, Staphylococcus aureus genetics, Staphylococcus aureus drug effects, Staphylococcus aureus isolation & purification, Staphylococcus aureus pathogenicity, Anti-Bacterial Agents pharmacology, Whole Genome Sequencing, Virulence Factors genetics, Leg Ulcer microbiology
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Background: Chronic leg ulcers are hard to treat and can be a burden, particularly in resource-limited settings where diagnosis is a challenge. Staphylococcus aureus is among the common bacteria isolated from chronic wounds with a great impact on wound healing, particularly in patients with co-morbidities. Antimicrobial resistance genes and virulence factors in Staphylococcus aureus isolates were assessed to support healthcare professionals to make better therapeutic choices, and importantly to curb the development and spread of antibiotic resistance., Methods: A cross-sectional study involved both inpatients and outpatients with chronic leg ulcers was conducted from August 2022 to April 2023 in 2 health facilities in Kilimanjaro region in Tanzania. Antimicrobial susceptibility testing was done using the disk diffusion method. Further, whole genome sequencing was performed to study the genotypic characteristics of the isolates., Results: A total of 92 participants were recruited in which 9 participants were only positive for 10 Staphylococcus aureus isolates upon culture. Five STs among 9 isolates were identified. Most of them belonged to ST8 (44%), with 1 isolate does not belong to any ST. Additionally, 50% of the isolates were methicillin-resistant Staphylococcus aureus (MRSA). All S. aureus isolates had almost similar virulence factors such as hemolysin, proteases and evasions that promote toxin production, protease production and host immune evasion respectively. Moreover, all mecA positive S. aureus isolates were phenotypically susceptible to cefoxitin., Conclusion: Presence of mecA positive S. aureus isolates which are also phenotypically susceptible to cefoxitin implies the possibility of classifying MRSA as MSSA. This may result in the possible emergence of highly cefoxitin - resistant strains in health care and community settings when subsequently exposed to beta-lactam agents. Therefore, combination of whole genome sequencing and conventional methods is important in assessing bacterial resistance and virulence to improve management of patients., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024. Published by Elsevier B.V.)
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- 2024
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13. Genomic characterization of methicillin-resistant Staphylococcus aureus isolated from patients attending regional referral hospitals in Tanzania.
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Geofrey MA, Sauli E, Kanje LE, Beti M, Shayo MJ, Kuchaka D, van Zwetselaar M, Wadugu B, Mmbaga B, Mkumbaye SI, Kumburu H, and Sonda T
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- Humans, Tanzania epidemiology, Female, Male, Adult, Adolescent, Young Adult, Phylogeny, Middle Aged, Genomics, Cross-Sectional Studies, Referral and Consultation, Child, Bacterial Proteins genetics, Genome, Bacterial, Methicillin-Resistant Staphylococcus aureus genetics, Methicillin-Resistant Staphylococcus aureus isolation & purification, Staphylococcal Infections microbiology, Staphylococcal Infections epidemiology
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Background: Methicillin-resistant Staphylococcus aureus (MRSA) colonization increases the risk of subsequent infection by MRSA strain complex interlinking between hospital and community-acquired MRSA which increases the chance of drug resistance and severity of the disease., Objective: Genomic characterization of Staphylococcus aures strains isolated from patients attending regional referral hospitals in Tanzania., Methodology: A laboratory-based cross-sectional study using short read-based sequencing technology, (Nextseq550,Illumina, Inc. San diego, California, USA). The samples used were collected from patients attending selected regional referral hospitals in Tanzania under the SeqAfrica project. Sequences were analyzed using tools available in the center for genomic and epidemiology server, and visualization of the phylogenetic tree was performed in ITOL 6.0. SPSS 28.0 was used for statistical analysis., Results: Among 103 sequences of S. aureus, 48.5% (50/103) carry the mecA gene for MRSA. High proportions of MRSA were observed among participants aged between 18 and 34 years (52.4%), in females (54.3%), and among outpatients (60.5%). The majority of observed MRSA carried plasmids rep5a (92.0%), rep16 (90.0%), rep7c (90.0%), rep15 (82.0%), rep19 (80.0%) and rep10 (72.0%). Among all plasmids observed rep5a, rep16, rep20, and repUS70 carried the blaZ gene, rep10 carried the erm(C) gene and rep7a carried the tet(K) gene. MLST and phylogeny analysis reveal high diversity among MRSA. Six different clones were observed circulating at selected regional hospitals and MRSA with ST8 was dominant., Conclusion: The study reveals a significant presence of MRSA in Staphylococcus aureus strains from Tanzanian regional hospitals, with nearly half carrying the mecA gene. MRSA is notably prevalent among young adults, females, and outpatients, showing high genetic diversity and dominance of ST8. Various plasmids carrying resistance genes indicate a complex resistance profile, highlighting the need for targeted interventions to manage MRSA infections in Tanzania., (© 2024. The Author(s).)
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- 2024
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14. Short reads-based characterization of pathotype diversity and drug resistance among Escherichia coli isolated from patients attending regional referral hospitals in Tanzania.
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Kanje LE, Kumburu H, Kuchaka D, Shayo M, Juma MA, Kimu P, Beti M, van Zwetselaar M, Wadugu B, Mmbaga BT, Mkumbaye SI, and Sonda T
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- Tanzania, Humans, Drug Resistance, Bacterial genetics, Retrospective Studies, Anti-Bacterial Agents pharmacology, Microbial Sensitivity Tests, Referral and Consultation, Virulence Factors genetics, Escherichia coli genetics, Escherichia coli isolation & purification, Escherichia coli drug effects, Escherichia coli Infections microbiology, Escherichia coli Infections drug therapy
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Background: Escherichia coli is known to cause about 2 million deaths annually of which diarrhea infection is leading and typically occurs in children under 5 years old. Although Africa is the most affected region there is little information on their pathotypes diversity and their antimicrobial resistance., Objective: To determine the pathotype diversity and antimicrobial resistance among E. coli from patients attending regional referral hospitals in Tanzania., Materials and Methods: A retrospective cross-section laboratory-based study where a total of 138 archived E. coli isolates collected from 2020 to 2021 from selected regional referral hospitals in Tanzania were sequenced using the Illumina Nextseq550 sequencer platform. Analysis of the sequences was done in the CGE tool for the identification of resistance genes and virulence genes. SPSS version 20 was used to summarize data using frequency and proportion., Results: Among all 138 sequenced E. coli isolates, the most prevalent observed pathotype virulence genes were of extraintestinal E. coli UPEC fyuA gene 82.6% (114/138) and NMEC irp gene 81.9% (113/138). Most of the E. coli pathotypes observed exist as a hybrid due to gene overlapping, the most prevalent pathotypes observed were NMEC/UPEC hybrid 29.7% (41/138), NMEC/UPEC/EAEC hybrid 26.1% (36/138), NMEC/UPEC/DAEC hybrid 18.1% (25/138) and EAEC 15.2% (21/138). Overall most E. coli carried resistance gene to ampicillin 90.6% (125/138), trimethoprim 85.5% (118/138), tetracycline 79.9% (110/138), ciprofloxacin 76.1% (105/138) and 72.5% (100/138) Nalidixic acid. Hybrid pathotypes were more resistant than non-hybrid pathotypes., Conclusion: Whole genome sequencing reveals the presence of hybrid pathotypes with increased drug resistance among E. coli isolated from regional referral hospitals in Tanzania., (© 2024. The Author(s).)
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- 2024
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15. Antimicrobial resistance and heterogeneity of Neisseria gonorrhoeae isolated from patients attending sexually transmitted infection clinics in Lusaka, Zambia.
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Sarenje KL, van Zwetselaar M, Kumburu H, Sonda T, Mmbaga B, Ngalamika O, Maimbolwa MC, Siame A, Munsaka S, and Kwenda G
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- Humans, Neisseria gonorrhoeae genetics, Multilocus Sequence Typing, Zambia epidemiology, Cross-Sectional Studies, Drug Resistance, Bacterial genetics, Tetracycline, Ciprofloxacin, Penicillins, Microbial Sensitivity Tests, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Gonorrhea drug therapy, Gonorrhea epidemiology, Gonorrhea microbiology
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Background: Antimicrobial resistance (AMR) of Neisseria gonorrhoeae is a threat to public health as strains have developed resistance to antimicrobials available for the treatment of gonorrhea. Whole genome sequencing (WGS) can detect and predict antimicrobial resistance to enhance the control and prevention of gonorrhea. Data on the molecular epidemiology of N. gonorrhoeae is sparse in Zambia. This study aimed to determine the genetic diversity of N. gonorrhoeae isolated from patients attending sexually transmitted infection (STI) clinics in Lusaka, Zambia., Methods: A cross-sectional study that sequenced 38 N. gonorrhoeae isolated from 122 patients with gonorrhea from 2019 to 2020 was conducted. The AMR profiles were determined by the E-test, and the DNA was extracted using the NucliSens easyMaG magnetic device. Whole genome sequencing was performed on the Illumina NextSeq550 platform. The Bacterial analysis pipeline (BAP) that is readily available at: https://cge.cbs.dtu.dk/services/CGEpipeline-1.1 was used for the identification of the species, assembling the genome, multi-locus sequence typing (MLST), detection of plasmids and AMR genes. Phylogeny by single nucleotide polymorphisms (SNPs) was determined with the CCphylo dataset., Results: The most frequent STs with 18.4% of isolates each were ST
7363 , ST1921 and ST1582 , followed by ST1583 (13%), novel ST17026 (7.9%), ST1588 (7.9%), ST1596 (5.3%), ST11181 (5.3%), ST11750 (2.6/%) and ST11241 (2.6%) among the 38 genotyped isolates. The blaTeM-1B and tetM (55%) was the most prevalent combination of AMR genes, followed by blaTeM-1B (18.4%), tetM (15.8%), and the combination of blaTeM-1B, ermT, and tetL was 2.6% of the isolates. The AMR phenotypes were predicted in ciprofloxacin, penicillin, tetracycline, azithromycin, and cefixime. The combination of mutations 23.7% was gryA (S91F), parC (E91G), ponA (L421) and rpsJ (V57M), followed by 18.4% in gyrA (S91F), ponA (L421P), rpsJ (V57M), and 18.4% in gyrA (D95G, S91F), ponA (L421P), and rpsJ (V57M). The combinations in gyrA (D95G, S91F) and rpsJ (V57M), and gyrA (D95G, S91F), parC (E91F), ponA (L421P) and rpsJ (V57M) were 13.2% each of the isolates. Plasmid TEM-1 (84.2%), tetM (15.8%), and gonococcal genetic island (GGI) was detected in all isolates., Conclusion: This study revealed remarkable heterogeneity of N. gonorrhoeae with blaTEM-1 , tetM, ponA, gyrA, and parC genes associated with high resistance to penicillin, tetracycline, and ciprofloxacin demanding revision of the standard treatment guidelines and improved antimicrobial stewardship in Zambia., (© 2024. The Author(s).)- Published
- 2024
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16. Complete genome sequence of Brucella abortus isolated from a human blood culture sample in Tanzania.
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Mbwambo GA, van Zwetselaar M, Sonda T, Lukambagire AS, Njau JS, Wadugu B, Ignass IP, Amani NB, Hugho EA, Rubach MP, Sakasaka P, Oisso RS, Mkenda N, Shirima G, Ashford RT, Haydon DT, Maro VP, Kazwala RR, Kumburu HH, Mmbaga BT, and Halliday JEB
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Brucella abortus causes infections in humans and livestock. Bacterial isolates are challenging to obtain, and very little is known about the genomic epidemiology of this species in Africa. Here, we report the complete genome sequence of a Brucella abortus isolate cultured from a febrile human in northern Tanzania., Competing Interests: The authors declare no conflict of interest.
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- 2024
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17. Mortality associated with third-generation cephalosporin resistance in Enterobacterales bloodstream infections at eight sub-Saharan African hospitals (MBIRA): a prospective cohort study.
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Aiken AM, Rehman AM, de Kraker MEA, Madrid L, Kebede M, Labi AK, Obeng-Nkrumah N, Nyamwaya B, Kagucia E, Cocker D, Kawaza K, Lester R, Iregbu KC, Medugu N, Nwajiobi-Princewill PI, Dramowski A, Sonda T, Hemed A, Fwoloshi S, Ojok D, Scott JAG, and Whitelaw A
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- Infant, Newborn, Humans, Prospective Studies, Cephalosporin Resistance, Cohort Studies, Hospital Mortality, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Escherichia coli, Hospitals, Cephalosporins pharmacology, Cephalosporins therapeutic use, Sepsis drug therapy
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Background: Bacteria of the order Enterobacterales are common pathogens causing bloodstream infections in sub-Saharan Africa and are frequently resistant to third-generation cephalosporin antibiotics. Although third-generation cephalosporin resistance is believed to lead to adverse outcomes, this relationship is difficult to quantify and has rarely been studied in this region. We aimed to measure the effects associated with resistance to third-generation cephalosporins in hospitalised patients with Enterobacterales bloodstream infection in Africa., Methods: We conducted a prospective, matched, parallel cohort study at eight hospitals across sub-Saharan Africa. We recruited consecutive patients of all age groups with laboratory-confirmed Enterobacterales bloodstream infection and matched them to at least one patient without bloodstream infection on the basis of age group, hospital ward, and admission date. Date of infection onset (and enrolment) was defined as the day of blood sample collection for culturing. Patients infected with bacteria with a cefotaxime minimum inhibitory concentration of 1 mg/L or lower were included in the third-generation cephalosporin-susceptible (3GC-S) cohort, and the remainder were included in the third-generation cephalosporin-resistant (3GC-R) cohort. The primary outcomes were in-hospital death and death within 30 days of enrolment. We used adjusted multivariable regression models to first compare patients with bloodstream infection against matched patients within the 3GC-S and 3GC-R cohorts, then compared estimates between cohorts., Findings: Between Nov 1, 2020, and Jan 31, 2022, we recruited 878 patients with Enterobacterales bloodstream infection (221 [25·2%] to the 3GC-S cohort and 657 [74·8%] to the 3GC-R cohort) and 1634 matched patients (420 [25·7%] and 1214 [74·3%], respectively). 502 (57·2%) bloodstream infections occurred in neonates and infants (age 0-364 days). Klebsiella pneumoniae (393 [44·8%] infections) and Escherichia coli (224 [25·5%] infections) were the most common Enterobacterales species identified. The proportion of patients who died in hospital was higher in patients with bloodstream infection than in matched controls in the 3GC-S cohort (62 [28·1%] of 221 vs 22 [5·2%] of 420; cause-specific hazard ratio 6·79 [95% CI 4·06-11·37] from Cox model) and the 3GC-R cohort (244 [37·1%] of 657 vs 115 [9·5%] of 1214; 5·01 [3·96-6·32]). The ratio of these cause-specific hazard ratios showed no significant difference in risk of in-hospital death in the 3GC-R cohort versus the 3GC-S cohort (0·74 [0·42-1·30]). The ratio of relative risk of death within 30 days (0·82 [95% CI 0·53-1·27]) also indicated no difference between the cohorts., Interpretation: Patients with bloodstream infections with Enterobacterales bacteria either resistant or susceptible to third-generation cephalosporins had increased mortality compared with uninfected matched patients, with no differential effect related to third-generation cephalosporin-resistance status. However, this finding does not account for time to appropriate antibiotic treatment, which remains clinically important to optimise. Measures to prevent transmission of Enterobacterales could reduce bloodstream infection-associated mortality from both drug-resistant and drug-susceptible bacterial strains in Africa., Funding: Bill & Melinda Gates Foundation., Competing Interests: Declaration of interests JAGS declares research grants (paid to their institution) from the Wellcome Trust; UK Medical Research Council; UK National Institute for Health and Care Research; UK Foreign, Commonwealth & Development Office; Bill & Melinda Gates Foundation; and the EU. All other authors 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.)
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- 2023
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18. Molecular Characterization of Staphylococcus aureus Isolated from Raw Milk and Humans in Eastern Tanzania: Genetic Diversity and Inter-Host Transmission.
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Mzee T, Kumburu H, Kazimoto T, Leekitcharoenphon P, van Zwetselaar M, Masalu R, Mlaganile T, Sonda T, Wadugu B, Mushi I, Aarestrup FM, and Matee M
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Staphylococcus aureus is a common cause of infection in humans and animals, including bovine mastitis, globally. The objective of this study was to genetically characterize a collection of S. aureus isolates recovered from milk and nasal swabs from humans with and without animal contact (bovine = 43, human = 12). Using whole genome sequencing (NextSeq550), isolates were sequence typed, screened for antimicrobial resistance and virulence genes and examined for possible inter-species host transmission. Multi locus sequence typing (MLST) and single nucleotide polymorphism (SNP)-based phylogeny revealed 14 different sequence types, including the following six novel sequence types: ST7840, 7841, 7845, 7846, 7847, and 7848. The SNP tree confirmed that MLST clustering occurred most commonly within CC97, CC5477, and CC152. ResFinder analysis revealed five common antibiotic resistance genes, namely tet (K), blaZ , dfrG , erm ©, and str , encoding for different antibiotics. mecA was discovered in one human isolate only. Multidrug resistance was observed in 25% of the isolates, predominantly in CC152 (7/8) and CC121 (3/4). Known bovine S. aureus (CC97) were collected in humans and known human S. aureus lineages (CC152) were collected in cattle; additionally, when these were compared to bovine-isolated CC97 and human-isolated CC152, respectively, no genetic distinction could be observed. This is suggestive of inter-host transmission and supports the need for surveillance of the human-animal interface.
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- 2023
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19. Circumstances for treatment and control of invasive Enterobacterales infections in eight hospitals across sub-Saharan Africa: a cross-sectional study.
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Aiken AM, Nyamwaya B, Madrid L, Edessa D, Labi AK, Obeng-Nkrumah N, Mwabaya W, Chimenya M, Cocker D, Iregbu KC, Princewill-Nwajiobi PIP, Dramowski A, Sonda T, Mmbaga BT, Ojok D, Fwoloshi S, Scott JAG, and Whitelaw A
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- Humans, Cross-Sectional Studies, Anti-Bacterial Agents therapeutic use, Hospitals, Africa South of the Sahara, Bacterial Infections drug therapy, Sepsis drug therapy
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Background: Bloodstream infections caused by Enterobacterales show high frequency of antimicrobial resistance (AMR) in many Low- and Middle-Income Countries. We aimed to describe the variation in circumstances for management of such resistant infections in a group of African public-sector hospitals participating in a major research study. Methods: We gathered data from eight hospitals across sub-Saharan Africa to describe hospital services, infection prevention and antibiotic stewardship activities, using two WHO-generated tools. We collected monthly cross-sectional data on availability of antibiotics in the hospital pharmacies for bloodstream infections caused by Enterobacterales. We compared the availability of these antibiotics to actual patient-level use of antibiotics in confirmed Enterobacterales bloodstream infections (BSI). Results: Hospital circumstances for institutional management of resistant BSI varied markedly. This included self-evaluated infection prevention level (WHO-IPCAF score: median 428, range 155 to 687.5) and antibiotic stewardship activities (WHO stewardship toolkit questions: median 14.5, range 2 to 23). These results did not correlate with national income levels. Across all sites, ceftriaxone and ciprofloxacin were the most consistently available antibiotic agents, followed by amoxicillin, co-amoxiclav, gentamicin and co-trimoxazole. There was substantial variation in the availability of some antibiotics, especially carbapenems, amikacin and piperacillin-tazobactam with degree of access linked to national income level. Investigators described out-of-pocket payments for access to additional antibiotics at 7/8 sites. The in-pharmacy availability of antibiotics correlated well with actual use of antibiotics for treating BSI patients. Conclusions: There was wide variation between these African hospitals for a range of important circumstances relating to treatment and control of severe bacterial infections, though these did not all correspond to national income level. For most antibiotics, patient-level use reflected in-hospital drug availability, suggesting external antibiotics supply was infrequent. Antimicrobial resistant bacterial infections could plausibly show different clinical impacts across sub-Saharan Africa due to this contextual variation., Competing Interests: No competing interests were disclosed., (Copyright: © 2023 Aiken AM et al.)
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- 2023
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20. Plasmid characterization in bacterial isolates of public health relevance in a tertiary healthcare facility in Kilimanjaro region, Tanzania.
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Sengeruan LP, van Zwetselaar M, Kumburu H, Aarestrup FM, Kreppel K, Sauli E, and Sonda T
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- Escherichia coli genetics, Plasmids genetics, Tanzania epidemiology, Tertiary Healthcare, Klebsiella pneumoniae genetics, Public Health
- Abstract
Objectives: Plasmids are infectious double stranded DNA molecules that are found within bacteria. Horizontal gene transfer promotes successful spread of different types of plasmids within or among bacteria species, making their detection an important task for guiding clinical treatment. We used whole genome sequenced data to determine the prevalence of plasmid replicon types in clinical bacterial isolates, the presence of resistance and virulence genes in plasmid replicon types, and the relationship between resistance and virulence genes within each plasmid replicon., Methods: All bacterial sequences were de novo assembled using Unicycler before extraction of plasmids. Assembly graphs were submitted to Gplas+plasflow for plasmid contigs prediction. The predicted plasmid contigs were validated using PlasmidFinder., Results: A total of 159 (56.2%) out of 283 bacterial isolates were found to carry plasmid replicons, with Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus being the most prevalent plasmid carriers. A total of 26 (86.7%) multiple-replicon types were found to carry both resistance and virulence genes compared to 4 (13.3%) single plasmid replicons. No statistically significant correlation was found between the number of antibiotic resistance and virulence genes in multiple-replicon types (r = - 0.14, P > 0.05)., Conclusion: Our findings show a relatively high proportion of plasmid replicon-carrying isolates suggesting selection pressure due to antibiotic use in the hospital. Co-occurrence of antibiotic resistance and virulence genes in clinical isolates is a public health problem warranting attention., Competing Interests: Declaration of Competing Interest None declared., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2022
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21. Using WGS to identify antibiotic resistance genes and predict antimicrobial resistance phenotypes in MDR Acinetobacter baumannii in Tanzania.
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Kumburu HH, Sonda T, van Zwetselaar M, Leekitcharoenphon P, Lukjancenko O, Mmbaga BT, Alifrangis M, Lund O, Aarestrup FM, and Kibiki GS
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- Acinetobacter Infections epidemiology, Adult, Aged, Aged, 80 and over, Bacterial Proteins genetics, Bacterial Proteins metabolism, Child, Female, Genome, Bacterial, Humans, Male, Middle Aged, Mutation, Tanzania epidemiology, Whole Genome Sequencing, Young Adult, Acinetobacter Infections microbiology, Acinetobacter baumannii drug effects, Anti-Bacterial Agents pharmacology, Drug Resistance, Multiple, Bacterial
- Abstract
Background: Reliable phenotypic antimicrobial susceptibility testing can be a challenge in clinical settings in low- and middle-income countries. WGS is a promising approach to enhance current capabilities., Aim: To study diversity and resistance determinants and to predict and compare resistance patterns from WGS data of Acinetobacter baumannii with phenotypic results from classical microbiological testing at a tertiary care hospital in Tanzania., Methods and Results: MLST using Pasteur/Oxford schemes yielded eight different STs from each scheme. Of the eight, two STs were identified to be global clones 1 (n = 4) and 2 (n = 1) as per the Pasteur scheme. Resistance testing using classical microbiology determined between 50% and 92.9% resistance across all drugs. Percentage agreement between phenotypic and genotypic prediction of resistance ranged between 57.1% and 100%, with coefficient of agreement (κ) between 0.05 and 1. Seven isolates harboured mutations at significant loci (S81L in gyrA and S84L in parC). A number of novel plasmids were detected, including pKCRI-309C-1 (219000 bp) carrying 10 resistance genes, pKCRI-43-1 (34935 bp) carrying two resistance genes and pKCRI-49-1 (11681 bp) and pKCRI-28-1 (29606 bp), each carrying three resistance genes. New ampC alleles detected included ampC-69, ampC-70 and ampC-71. Global clone 1 and 2 isolates were found to harbour ISAba1 directly upstream of the ampC gene. Finally, SNP-based phylogenetic analysis of the A. baumannii isolates revealed closely related isolates in three clusters., Conclusions: The validity of the use of WGS in the prediction of phenotypic resistance can be appreciated, but at this stage is not sufficient for it to replace conventional antimicrobial susceptibility testing in our setting., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.)
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- 2019
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22. Prevalence and associated risk factors for Kaposi's sarcoma among HIV-positive patients in a referral hospital in Northern Tanzania: a retrospective hospital-based study.
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Semango GP, Charles RM, Swai CI, Mremi A, Amsi P, Sonda T, Shao ER, Mavura DR, Joosten LAB, Sauli E, and Nyindo M
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- Adolescent, Adult, Age Factors, CD4 Lymphocyte Count, Child, Child, Preschool, Cross-Sectional Studies, Female, HIV Infections immunology, Humans, Infant, Infant, Newborn, Male, Prevalence, Referral and Consultation, Retrospective Studies, Risk Factors, Sex Factors, Tanzania, Young Adult, HIV Infections complications, Sarcoma, Kaposi epidemiology
- Abstract
Background: Kaposi's sarcoma (KS) is a multifocal angioproliferative tumor involving blood and lymphatic vessels, caused by Human Herpes Virus-8 (HHV-8). KS is an important AIDS-defining tumor with high prevalence in Sub-Saharan Africa, including Tanzania which has high HIV and HHV-8 sero-prevalence. It is critically important to monitor the prevalence of AIDS-defining tumors, such as KS, in the age of HIV/AIDS. We studied the prevalence of KS and associated risk factors among HIV-positive patients at Kilimanjaro Christian Medical Centre (KCMC), a referral hospital in northern Tanzania, over the period from January 2012 to December 2015., Methods: This was a retrospective hospital-based cross-sectional study to determine the prevalence of KS among HIV/AIDS patients between 2012 and 2015. The study included 1100 HIV patients' data which were collected at the Infectious Disease Clinic (IDC) from patients' files. Stata version 13 (StataCorp LP, Texas 77,845 USA) was used for all statistical analyses. The prevalence of KS was calculated across levels of a number of categorical variables. Logistic regression was performed to determine relative risk of KS for all characteristics. We included all variables with p-values ≤10% in the multivariate analysis, including ART use, as this is considered to have an influence on KS. In the multivariate analysis, statistical significance was established based on a two-tailed p-value ≤5%. All patients' notes were kept confidential as per the Helsinki declaration., Results: Our results revealed a 4.6% prevalence of KS at KCMC hospital, between January 2012 and December 2015, 51(4.6%) patients were diagnosed with KS out of 1100 HIV-positive patients. The study further revealed that KS in HIV patients was most associated with low CD4 cell count (less than or equal to 200 cells/μl). Moreover, women were more likely than men to diagnosed with KS, with higher odds significantly associated with KS (OR 0.42, p < 0.009). Increased age, above 35 years, among the HIV seropositive patients was significantly associated with KS (OR 25.67, p < 0.007). HIV patients who were none smokers were more likely to suffer from KS compared to HIV smokers (OR 0.41, p < 0.010)., Conclusion: KS remains a common malignant vascular tumor commonly associated with HIV/AIDS in Tanzania. Our study highlights the need for continued efforts to combat HIV, as well as associated diseases such as KS. Continued availability of ART (Anti-Retroviral Therapy) to HIV/AIDS patients, and test reagents for CD4 cell count and viral load determination are important measures to alleviate the suffering of these patients. Furthermore, studies to gather more evidence on ART resistance are highly needed to guide treatment choices.
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- 2018
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23. Molecular epidemiology of virulence and antimicrobial resistance determinants in Klebsiella pneumoniae from hospitalised patients in Kilimanjaro, Tanzania.
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Sonda T, Kumburu H, van Zwetselaar M, Alifrangis M, Mmbaga BT, Lund O, Kibiki GS, and Aarestrup FM
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- Adult, Aged, Aged, 80 and over, Anti-Bacterial Agents pharmacology, Child, Cross-Sectional Studies, Drug Resistance, Bacterial drug effects, Female, Hospitals, Humans, Klebsiella Infections drug therapy, Klebsiella Infections epidemiology, Klebsiella pneumoniae genetics, Male, Middle Aged, Molecular Epidemiology, Phylogeny, Plasmids genetics, Tanzania, Virulence genetics, beta-Lactamases genetics, Drug Resistance, Bacterial genetics, Klebsiella Infections microbiology, Klebsiella pneumoniae drug effects, Klebsiella pneumoniae pathogenicity
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This study aimed to use whole-genome sequencing to determine virulence and antimicrobial resistance genes in K. pneumoniae isolated from patients in a tertiary care hospital in Kilimanjaro. K. pneumoniae isolates from patients attending Kilimanjaro Christian Medical Centre between August 2013 and August 2015 were fully genome-sequenced and analysed locally. Sequence analysis was done for identification of virulence and AMR genes. Plasmid and multi-locus sequence typing and capsular or capsular (K) typing were performed and phylogeny was done to ascertain K. pneumoniae relatedness. Stata 13 (College Station, TX, 77845, USA) was used to determine Cohen's kappa coefficient of agreement between the phenotypically tested and sequence-predicted resistance. A total of 16 (47.1%) sequence types (STs) and 10 (29.4%) K types were identified in 30 (88.2%) and 17 (50.0%) of all analysed isolates, respectively. K. pneumoniae ST17 were 6 (17.6%). The commonest determinants were bla
CTX-M-15 in 16 (47.1%) isolates, blaSHV in 30 (88.2%), blaOXA-1 in 8 (23.5%) and blaTEM-1 in 18 (52.9%) isolates. Resistance genes for aminoglycosides were detected in 21 (61.8%) isolates, fluoroquinolones in 13 (38.2%) and quinolones 34 (100%). Ceftazidime and ceftriaxone showed the strongest agreement between phenotype- and sequence-based resistance results: 93.8%, kappa = 0.87 and p = 0.0002. Yersiniabactin determinant was detected in 12 (35.3%) of K. pneumoniae. The proportion of AMR and virulence determinants detected in K. pneumoniae is alarming. WGS-based diagnostic approach has showed promising potentials in clinical microbiology, hospital outbreak source tracing virulence and AMR detection at KCMC.- Published
- 2018
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24. Whole genome sequencing reveals high clonal diversity of Escherichia coli isolated from patients in a tertiary care hospital in Moshi, Tanzania.
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Sonda T, Kumburu H, van Zwetselaar M, Alifrangis M, Mmbaga BT, Aarestrup FM, Kibiki G, and Lund O
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- Amoxicillin-Potassium Clavulanate Combination pharmacology, Cross-Sectional Studies, Escherichia coli classification, Escherichia coli genetics, Genome, Bacterial genetics, Humans, Microbial Sensitivity Tests, Multilocus Sequence Typing, Phylogeny, Tanzania epidemiology, Trimethoprim, Sulfamethoxazole Drug Combination pharmacology, Virulence Factors, Whole Genome Sequencing, beta-Lactamases genetics, Anti-Bacterial Agents pharmacology, Drug Resistance, Multiple, Bacterial genetics, Escherichia coli drug effects, Escherichia coli isolation & purification, Escherichia coli Infections epidemiology, Hospitals statistics & numerical data, Tertiary Care Centers statistics & numerical data, beta-Lactam Resistance genetics
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Background: Limited information regarding the clonality of circulating E. coli strains in tertiary care hospitals in low and middle-income countries is available. The purpose of this study was to determine the serotypes, antimicrobial resistance and virulence genes. Further, we carried out a phylogenetic tree reconstruction to determine relatedness of E. coli isolated from patients in a tertiary care hospital in Tanzania., Methods: E. coli isolates from inpatients admitted at Kilimanjaro Christian Medical Centre between August 2013 and August 2015 were fully genome-sequenced at KCMC hospital. Sequence analysis was done for identification of resistance genes, Multi-Locus Sequence Typing, serotyping, and virulence genes. Phylogeny reconstruction using CSI Phylogeny was done to ascertain E. coli relatedness. Stata 13 (College Station, Texas 77,845 USA) was used to determine Cohen's kappa coefficient of agreement between the phenotypically tested and whole genome sequence predicted antimicrobial resistance., Results: Out of 38 E. coli isolates, 21 different sequence types (ST) were observed. Eight (21.1%) isolates belonged to ST131; of which 7 (87.5.%) were serotype O25:H4. Ten (18.4%) isolates belonged to ST10 clonal complex; of these, four (40.0%) were ST617 with serotype O89:H10. Twenty-eight (73.7%) isolates carried genes encoding beta-lactam resistance enzymes . On average, agreement across all drugs tested was 83.9%. Trimethoprim/sulphamethoxazole (co-trimoxazole) showed moderate agreement: 45.8%, kappa =15% and p = 0.08. Amoxicillin-clavulanate showed strongest agreement: 87.5%, kappa = 74% and p = 0.0001. Twenty-two (57.9%) isolates carried virulence factors for host cells adherence and 25 (65.7%) for factors that promote E. coli immune evasion by increasing survival in serum. The phylogeny analysis showed that ST131 clustering close together whereas ST10 clonal complex had a very clear segregation of the ST617 and a mix of the rest STs., Conclusion: There is a high diversity of E. coli isolated from patients admitted to a tertiary care hospital in Tanzania. This underscores the necessity to routinely screen all bacterial isolates of clinical importance in tertiary health care facilities. WGS use for laboratory-based surveillance can be an effective early warning system for emerging pathogens and resistance mechanisms in LMICs., Competing Interests: This study was granted ethical approval by the KCMC Research Ethics Committee and the National Institute for Medical Research with approval numbers 893 and NIMR/HQ/R.8a/Vol.IX/2080 respectively. A written informed consent was obtained from each participant or from parents or guardians of children before enrolment into the study.The authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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- 2018
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25. Prevalence and risk factors for CTX-M gram-negative bacteria in hospitalized patients at a tertiary care hospital in Kilimanjaro, Tanzania.
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Sonda T, Kumburu H, van Zwetselaar M, Alifrangis M, Mmbaga BT, Lund O, Aarestrup FM, and Kibiki G
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- Adult, Comorbidity, Cross-Sectional Studies, Female, Genome, Bacterial, Gram-Negative Bacteria drug effects, Gram-Negative Bacterial Infections drug therapy, Humans, Male, Middle Aged, Prevalence, Public Health Surveillance, Risk Factors, Tanzania epidemiology, Whole Genome Sequencing, beta-Lactam Resistance, Cross Infection, Gram-Negative Bacteria genetics, Gram-Negative Bacterial Infections epidemiology, Gram-Negative Bacterial Infections microbiology, Tertiary Care Centers, beta-Lactamases genetics
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Emergence and spread of extended spectrum beta-lactamase (ESBL)-producing gram-negative bacteria, mainly due to CTX-M, is a major global public health problem. Patients infected with ESBL-producing gram-negative bacteria have an increased risk of treatment failure and death. We investigated the prevalence and risk factors for CTX-M gram-negative bacteria isolated from clinical specimens of patients hospitalized at a tertiary care hospital in Kilimanjaro, Tanzania. Isolated gram-negative bacteria from inpatients admitted at Kilimanjaro Christian Medical Centre (KCMC) between August 2013 and August 2015 were fully genome sequenced. The prevalence of ESBL-producing gram-negative bacteria was determined based on the presence of bla
CTX-M . The odds ratio (OR) and risk factors for ESBL-producing gram-negative bacteria due to CTX-M were assessed using logistic regression models. The overall CTX-M prevalence (95% CI) was 13.6% (10.1-18.1). Adjusted for other factors, the OR of CTX-M gram-negative bacteria for patients previously hospitalized was 0.26 (0.08-0.88), p = 0.031; the OR for patients currently on antibiotics was 4.02 (1.29-12.58), p = 0.017; the OR for patients currently on ceftriaxone was 0.14 (0.04-0.46), p = 0.001; and the OR for patients with wound infections was 0.24 (0.09-0.61), p = 0.003. The prevalence of ESBL-producing gram-negative bacteria due to CTX-M in this setting is relatively low compared to other previous reports in similar settings. However, to properly stop further spread in the hospital, we recommend setting up a hospital surveillance system that takes full advantage of the available next-generation sequencing facility to routinely screen for all types of bacterial resistance genes.- Published
- 2018
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26. Aeromonas caviae mimicking Vibrio cholerae infectious enteropathy in a cholera-endemic region with possible public health consequences: two case reports.
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van Zwetselaar M, Nyombi B, Sonda T, Kumburu H, Chamba N, Dekker MCJ, Kilonzo KG, Urasa SJ, and Mmbaga BT
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- Acetaminophen therapeutic use, Adult, Anti-Bacterial Agents therapeutic use, Ciprofloxacin therapeutic use, Diagnosis, Differential, Doxycycline therapeutic use, Female, Humans, Intraabdominal Infections drug therapy, Metronidazole therapeutic use, Middle Aged, Tanzania, Young Adult, Aeromonas caviae isolation & purification, Cholera, Endemic Diseases, Intraabdominal Infections diagnosis, Public Health, Vibrio cholerae
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Background: Aeromonas species have been documented to yield false positive results in microbiological tests for Vibrio cholerae. They share many biochemical properties with Vibrio species, with which they were jointly classified in the family Vibrionaceae until genotypic information provided new insights. Aeromonas species are increasingly associated with gastrointestinal infections, albeit with great apparent variation in pathogenicity and virulence both between and within species of the genus. We report two cases with clinically mild cholera-like symptoms, at a time when a cholera outbreak was unfolding in other regions of the country (Tanzania). These are the first cases to be reported with Aeromonas mimicking cholera in our area., Case Presentation: Two patients were admitted at the isolation unit designated by the Kilimanjaro Christian Medical Centre for emerging infectious diseases and provided informed consent about regular stool analysis and culture under the provisional diagnosis of gastroenteritis. The first patient was a 23-year-old black African woman with a 2-day history of watery diarrhea and vomiting associated with a temperature of 39.7 °C. The second patient was a 47-year-old black African woman with a 2-day history of diarrhea and vomiting with a temperature of 37.7 °C, and she was hemodynamically stable. Both patients were isolated in a specific area for infection control and treated with fluids and orally administered rehydration solution, ciprofloxacin, metronidazole, and paracetamol. Stool culture was done. The isolated colonies were reported as V. cholerae and transferred to the research laboratory of Kilimanjaro Clinical Research Institute for confirmation using whole genome sequencing. Microbiological testing determined colonies isolated from stool to be V. cholerae, and warranted the conclusion "presumptive cholera." Whole genome sequencing, however, established the presence of Aeromonas caviae rather than V. cholerae., Conclusions: The co-existence of Aeromonas species with V. cholerae in cholera-endemic regions suggests the possibility that a proportion of suspected cholera cases may be Aeromonas infections. However, with close to no epidemiological data available on Aeromonas infection in cases of diarrhea and dysentery in Sub-Saharan Africa, it is not currently possible to establish the extent of misdiagnosis to any degree of certainty. Whole genome sequencing was shown to readily exclude V. cholerae as the etiological agent and establish the presence of Aeromonas species.
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- 2018
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27. Hospital Epidemiology of Methicillin-Resistant Staphylococcus aureus in a Tertiary Care Hospital in Moshi, Tanzania, as Determined by Whole Genome Sequencing.
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Kumburu HH, Sonda T, Leekitcharoenphon P, van Zwetselaar M, Lukjancenko O, Alifrangis M, Lund O, Mmbaga BT, Kibiki G, and Aarestrup FM
- Subjects
- Anti-Bacterial Agents therapeutic use, Chloramphenicol therapeutic use, Humans, Methicillin-Resistant Staphylococcus aureus drug effects, Molecular Epidemiology methods, Phylogeny, Polymorphism, Single Nucleotide genetics, Staphylococcal Infections drug therapy, Tanzania epidemiology, Tertiary Care Centers, Vancomycin therapeutic use, Whole Genome Sequencing methods, Methicillin-Resistant Staphylococcus aureus genetics, Staphylococcal Infections epidemiology, Staphylococcal Infections microbiology
- Abstract
Objective: To determine molecular epidemiology of methicillin-resistant S. aureus in Tanzania using whole genome sequencing., Methods: DNA from 33 Staphylococcus species was recovered from subcultured archived Staphylococcus isolates. Whole genome sequencing was performed on Illumina Miseq using paired-end 2 × 250 bp protocol. Raw sequence data were analyzed using online tools., Results: Full susceptibility to vancomycin and chloramphenicol was observed. Thirteen isolates (43.3%) resisted cefoxitin and other antimicrobials tested. Multilocus sequence typing revealed 13 different sequence types among the 30 S. aureus isolates, with ST-8 ( n = seven, 23%) being the most common. Gene detection in S . aureus stains were as follows: mecA , 10 (33.3%); pvl , 5 (16.7%); tst , 2 (6.7%). The SNP difference among the six Tanzanian ST-8 MRSA isolates ranged from 24 to 196 SNPs and from 16 to 446 SNPs when using the USA300_FPR3757 or the USA500_2395 as a reference, respectively. The mutation rate was 1.38 × 10
-11 SNPs/site/year or 1.4 × 10-6 SNPs/site/year as estimated by USA300_FPR3757 or the USA500_2395, respectively., Conclusion: S. aureus isolates causing infections in hospitalized patients in Moshi are highly diverse and epidemiologically unrelated. Temporal phylogenetic analysis provided better resolution on transmission and introduction of MRSA and it may be important to include this in future routines.- Published
- 2018
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28. Exploring the Role of IL-32 in HIV-Related Kaposi Sarcoma.
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Semango G, Heinhuis B, Plantinga TS, Blokx WAM, Kibiki G, Sonda T, Mavura D, Masenga EJ, Nyindo M, van der Ven AJAM, and Joosten LAB
- Subjects
- Apoptosis genetics, Chemokines, CXC metabolism, Cyclooxygenase 2 metabolism, Cytokines metabolism, Disease Progression, HIV Infections complications, HIV Infections pathology, Humans, Sarcoma, Kaposi pathology, Sarcoma, Kaposi virology, Signal Transduction physiology, Skin pathology, Skin virology, Skin Neoplasms pathology, Skin Neoplasms virology, HIV Infections metabolism, Interleukins metabolism, Sarcoma, Kaposi metabolism, Skin metabolism, Skin Neoplasms metabolism
- Abstract
The intracellular proinflammatory mediator IL-32 is associated with tumor progression; however, the mechanisms remain unknown. We studied IL-32 mRNA expression as well as expression of other proinflammatory cytokines and mediators, including IL-1α, IL-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, the proangiogenic and antiapoptotic enzyme cyclooxygenase-2, the IL-8 receptor C-X-C chemokine receptor (CXCR) 1, and the intracellular kinase focal adhesion kinase-1. The interaction of IL-32 expression with expression of IL-6, TNF-α, IL-8, and cyclooxygenase-2 was also investigated. Biopsy specimens of 11 HIV-related, 7 non-HIV-related Kaposi sarcoma (KS), and 7 normal skin tissues (NSTs) of Dutch origin were analyzed. RNA was isolated from the paraffin material, and gene expression levels of IL-32 α, β, and γ isoforms, IL1a, IL1b, IL6, IL8, TNFA, PTGS2, CXCR1, and PTK2 were determined using real-time quantitative PCR. Significantly higher expression of IL-32β and IL-32γ isoforms was observed in HIV-related KS biopsy specimens compared with non-HIV-related KS and NST. The splicing ratio of the IL-32 isoforms showed IL-32γ as the highest expressed isoform, followed by IL-32β, in HIV-related KS cases compared with non-HIV-related KS and NST. Our data suggest a possible survival mechanism by the splicing of IL-32γ to IL-32β and also IL-6, IL-8, and CXCR1 signaling pathways to reverse the proapoptotic effect of the IL-32γ isoform, leading to tumor cell survival and thus favoring tumor progression., (Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)
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- 2018
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29. Patterns of infections, aetiological agents and antimicrobial resistance at a tertiary care hospital in northern Tanzania.
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Kumburu HH, Sonda T, Mmbaga BT, Alifrangis M, Lund O, Kibiki G, and Aarestrup FM
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- Adult, Anti-Bacterial Agents therapeutic use, Bacteria isolation & purification, Bacterial Infections drug therapy, Female, Humans, Male, Microbial Sensitivity Tests, Middle Aged, Tanzania, Anti-Bacterial Agents pharmacology, Bacteria growth & development, Bacterial Infections microbiology, Drug Resistance, Bacterial, Drug Resistance, Multiple, Tertiary Care Centers
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Objective: To determine the causative agents of infections and their antimicrobial susceptibility at a tertiary care hospital in Moshi, Tanzania, to guide optimal treatment., Methods: A total of 590 specimens (stool (56), sputum (122), blood (126) and wound swabs (286)) were collected from 575 patients admitted in the medical and surgical departments. The bacterial species were determined by conventional methods, and disc diffusion was used to determine the antimicrobial susceptibility pattern of the bacterial isolates., Results: A total of 249 (42.2%) specimens were culture-positive yielding a total of 377 isolates. A wide range of bacteria was isolated, the most predominant being Gram-negative bacteria: Proteus spp. (n = 48, 12.7%), Escherichia coli (n = 44, 11.7%), Pseudomonas spp. (n = 40, 10.6%) and Klebsiella spp (n = 38, 10.1%). Wound infections were characterised by multiple isolates (n = 293, 77.7%), with the most frequent being Proteus spp. (n = 44, 15%), Pseudomonas (n = 37, 12.6%), Staphylococcus (n = 29, 9.9%) and Klebsiella spp. (n = 28, 9.6%). All Staphylococcus aureus tested were resistant to penicillin (n = 22, 100%) and susceptible to vancomycin. Significant resistance to cephalosporins such as cefazolin (n = 62, 72.9%), ceftriaxone (n = 44, 51.8%) and ceftazidime (n = 40, 37.4%) was observed in Gram-negative bacteria, as well as resistance to cefoxitin (n = 6, 27.3%) in S. aureus., Conclusion: The study has revealed a wide range of causative agents, with an alarming rate of resistance to the commonly used antimicrobial agents. Furthermore, the bacterial spectrum differs from those often observed in high-income countries. This highlights the imperative of regular generation of data on aetiological agents and their antimicrobial susceptibility patterns especially in infectious disease endemic settings. The key steps would be to ensure the diagnostic capacity at a sufficient number of sites and implement structures to routinely exchange, compare, analyse and report data. Sentinel sites (hospitals) across the country (and region) should report on a representative subset of bacterial species and their susceptibility to drugs at least annually. A central organising body should collate the data and report to relevant national and international stakeholders., (© 2017 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.)
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- 2017
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30. Naturally Acquired Antibody Responses to a Synthetic Malaria Antigen AS202.11.
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Nazareth R, Horumpende P, Sonda T, Ndaro A, Mollel E, Paul E, Athanase E, and Chilongola J
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Background: A major challenge to malaria vaccine development is identification of protective epitopes and respective protective immune responses., Objective: To characterize naturally acquired Immunoglobulin G (IgG) responses to the synthetic peptide AS202.11, a malaria vaccine candidate., Methodology: This community based cross-sectional study enrolled 320 participants aged 1 year and above. Demographic information was recorded through interviews. Detection of P. falciparum infection was done by microscopy, malaria rapid diagnostic test, and polymerase chain reaction. ELISA was used to detect IgG antibody. Data was analyzed using STATA., Results: The overall AS202.11 IgG seropositivity was 78.8% (73.9-82.9). Seropositivity by age categories was ≤12 years [74.3% (67.4-80.2)], 13-40 years [85.3% (76.5-91.1)], and >40 years [82.6% (68.7-91.1)]. Compared to the ≤ 12-year-old group, aORs for the other groups were 2.22 (1.14-4.32), p = 0.019, and 1.87 (0.81-4.35), p = 0.143, for the 13-40-year-old and >40-year-old groups, respectively. The 13-40-year-old group had more seropositive individuals compared to the ≤ 12-year-old group., Conclusion: We report a high degree of recognition of AS202.11 by IgG elicited by field P. falciparum strains, suggesting its close similarity to native P. falciparum antigens and possible suitability of the peptide as a future malaria vaccine candidate.
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- 2017
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31. Meta-analysis of proportion estimates of Extended-Spectrum-Beta-Lactamase-producing Enterobacteriaceae in East Africa hospitals.
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Sonda T, Kumburu H, van Zwetselaar M, Alifrangis M, Lund O, Kibiki G, and Aarestrup FM
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Background: A high proportion of Extended-Spectrum-Beta-Lactamase (ESBL) producing Enterobacteriaceae is causing common infections in all regions of the world. The burden of antibiotic resistance due to ESBL in East Africa is large but information is scarce and thus it is unclear how big the problem really is. To gain insight into the magnitude and molecular epidemiology of ESBL-producing Enterobacteriaceae in East Africa a literature search was performed in PubMed on 31 July 2015 to retrieve articles with relevant information on ESBL., Methods and Results: Meta-analysis was performed to determine overall proportion estimate of ESBL-producing Enterobacteriaceae. A total of 4076 bacterial isolates were included in the analysis. The overall pooled proportion of ESBL-producing Enterobacteriaceae among included surveys done in East African hospitals was found to be 0.42 (95 % CI: 0.34-0.50). Heterogeneity (I(2)) between countries' proportions in ESBL was significantly high (96.95 % and p < 0.001). The frequently detected genes encoding ESBL were CTX-M, TEM, SHV and OXA while the most infrequent reported genes were KPC and NDM., Conclusion: The available studies show a very wide variation in resistance due to ESBL between countries. This highlights a need for active surveillance systems which can help understand the actual epidemiology of ESBL, aid in formulating national or regional guidelines for proper screening of ESBL, and support developing standardized approaches for managing patients colonized with ESBL.
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- 2016
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32. Benchtop Whole-Genome Sequencing for Identification of Nosocomial Outbreaks in Tanzania.
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Sonda T, Kumburu H, Zwetselaar Mv, Ahrenfeldt J, Alifrangis M, Lund O, Kibiki G, and Aarestrup FM
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- Disease Outbreaks, Humans, Tanzania epidemiology, Cross Infection epidemiology, Sequence Analysis, DNA methods
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- 2016
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33. [Eating disorder and cyclothymic temperament: cross-sectional study about 107 Tunisian students].
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Jaweher M, sonda T, uta O, Inès F, Rim S, Imene B, and Abdelaziz J
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- Adult, Cross-Sectional Studies, Cyclothymic Disorder complications, Feeding and Eating Disorders complications, Female, Humans, Male, Prevalence, Socioeconomic Factors, Students statistics & numerical data, Tunisia epidemiology, Young Adult, Cyclothymic Disorder epidemiology, Feeding and Eating Disorders epidemiology
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- 2014
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34. The Gap Between Knowledge and Practice of Risky Sexual Behaviors for HIV Among University Students and Staff in Moshi Town in Tanzania.
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Kwigizile E, Shao E, Mtango G, Sonda T, Moshi J, and Chilongola J
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Knowledge on HIV spread is important in combating HIV/AIDS, however its impact can only be realized if put into practice. This study was carried out in a Higher Learning Institution in Moshi Township in Kilimanjaro Region to assess the level of awareness of university communities about HIV/AIDs and its link with practice of risky sexual behaviors (RSB). We have found an adequate level of knowledge on the spread, risk behaviors and methods for protection leading to attendance to voluntary testing and counseling by 61% of respondents. Conversely, we have observed great extent of practice of RSBs including early sexual debut (16.7 years), having multiple and extramarital partners, involvement in practices that lead to unprotected sexual intercourse. We report an obvious gap between knowledge and behavior. This study therefore recommends that serious operational interventions must be put in place targeting the most sexually active groups, the youth in preliminary schools to sensitize on RSBs and ways to avoid them before they are engaged in sexual activities., Competing Interests: Conflict of interests: the authors declare no potential conflict of interests.
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- 2013
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35. Effects of the molecular properties of mixed solvents on the elution of alkyl benzoates in RPLC.
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Yasuda M, Sonda T, Hiraoka T, Horita A, and Tabata M
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- Chromatography, High Pressure Liquid standards, Hazardous Substances analysis, Hydrogen Bonding, Syzygium chemistry, Benzoates isolation & purification, Chromatography, High Pressure Liquid methods, Solvents chemistry
- Abstract
The retention behavior and mechanism of methyl, ethyl, propyl, isopropyl, buthyl and isobuthyl benzoates have been studied at different eluent compositions of aqueous mixtures with water-soluble organic solvents (methanol, ethanol, 1-propanol, 2-propanol, acetonitrile (AN), 1,4-dioxane and tetrahydrofuran (THF)) in RPLC. The retention of the solutes is discussed based on the solvent composition, solvent polarity (ETN value), preferential solvation, hydrogen bonding and solvent clusters of the eluents. The smaller ETN values and the larger preferential solvation of the mixed solvent eluted the solutes faster. The IR spectra of HDO suggested that the solvents, except for methanol and ethanol, break the hydrogen bonding between water molecules, resulting in fast elution of the solutes. Based upon the results, we chose an optimum solvent composition for the separation of benzoates and applied it to the determination of the benzoates in clove.
- Published
- 2003
- Full Text
- View/download PDF
36. Effects of pH and metal ions on antioxidative activities of catechins.
- Author
-
Kumamoto M, Sonda T, Nagayama K, and Tabata M
- Subjects
- Antioxidants chemistry, Antioxidants metabolism, Catechin analogs & derivatives, Catechin chemistry, Catechin metabolism, Catechols chemistry, Catechols metabolism, Catechols pharmacology, Humans, Hydrogen-Ion Concentration, Linoleic Acid metabolism, Metals chemistry, Metals metabolism, Molecular Structure, Oxidation-Reduction, Pyrogallol chemistry, Pyrogallol metabolism, Pyrogallol pharmacology, Tea chemistry, Antioxidants pharmacology, Catechin pharmacology, Metals pharmacology
- Abstract
The Effects of pH on antioxidative activities of catechol, pyrogallol, and four catechins, and effects of metal ions (Al3+, Ca2+, Cd2+, Co2+, Cr3+, Cu2+, Fe2+, Fe3+, K+, Mg2+, Mn2+, Na+, and Zn2+) on antioxidative activities of (-)-epigallocatechin gallate (EGCG) were studied by an oxygen electrode method. The antioxidative activities of catechins were high and constant at pH 6-12, but decreased in acidic and strong alkaline solutions. Copper(II) ion the most strongly increased the antioxidative activity of EGCG among these metal ions examined, but iron(II) ion largely inhibited the antioxidative activity of EGCG. These effects are discussed considering the formation of metal complexes with catechins and the change in oxidation potentials.
- Published
- 2001
- Full Text
- View/download PDF
37. Evaluation of the antioxidative activity of tea by an oxygen electrode method.
- Author
-
Kumamoto M and Sonda T
- Subjects
- Catechin chemistry, Catechin pharmacology, Electrodes, Evaluation Studies as Topic, Molecular Structure, Tea drug effects, Antioxidants metabolism, Catechin metabolism, Oxygen metabolism, Tea metabolism
- Abstract
The antioxidative activity was studied for 25 kinds of tea and catechins by a new evaluation method using an oxygen electrode. The concentration of catechins in 6 types of green tea was analyzed by HPLC. The result indicates that the antioxidative activity of green tea depends to some extent on the amount of catechins present.
- Published
- 1998
- Full Text
- View/download PDF
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