Department of Epidemiology and Biostatistics, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
Tanzania Field Epidemiology and Laboratory Training Program, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
PLoS One. 2022 Mar 25;17(3):e0265868. doi: 10.1371/journal.pone.0265868. eCollection 2022.
Cholera continues to cause morbidity and mortality in developing countries, including Tanzania. Since August 2015, Tanzania Mainland has experienced cholera outbreaks affecting 26 regions and a 1.6% case fatality rate. The current study determined the virulence factors, genetic relatedness and antimicrobial susceptibility patterns of the Vibrio cholerae isolated from different regions in Tanzania.
A cross-sectional study that involved the genetic characterization of V. cholerae isolates from eleven regions in Tanzania was carried out. There were 99 V. cholerae isolates collected between January 2016 and December 2017. The study perfomed a Multi-locus Variable-number tandem-repeat analysis for genetic relatedness and Mismatch Amplification Mutation Analysis polymerase chain reaction for analyzing toxin genes. All the isolates were tested for antimicrobial susceptibility using the Kirby Bauer disk diffusion method. Data were generally analyzed using Microsoft excel, where genetic relatedness was analyzed using eBurst software v3.
All isolates were V. cholerae O1. Ogawa was the most predominant 97(98%) serotype. Isolates were genetically related with a small genetic diversity and were positive for ctxA, tcpA El Tor virulence genes. All isolates (100%) were sensitive to doxycycline, trimethoprim-sulphamethoxazole, tetracycline, ceftriaxone, and chloramphenicol, while 87.8% were sensitive to ciprofloxacin. A high resistance rate (100%) was detected towards erythromycin, nalidixic acid, amoxicillin, and ampicillin.
The V.cholerae O1 serotypes Ogawa, El Tor variant predominantly caused cholera outbreaks in Tanzania with strains clonally related regardless of the place and time of the outbreak. Most of the isolates were susceptible to the antibiotic regimen currently used in Tanzania. The high resistance rate detected for the other common antibiotics calls for continuous antimicrobial susceptibility testing during outbreaks.
霍乱继续在发展中国家造成发病率和死亡率，包括坦桑尼亚。自 2015 年 8 月以来，坦桑尼亚大陆经历了影响 26 个地区的霍乱暴发，病死率为 1.6%。本研究旨在确定从坦桑尼亚不同地区分离的霍乱弧菌的毒力因子、遗传相关性和抗菌药物敏感性模式。
进行了一项横断面研究，涉及坦桑尼亚 11 个地区的霍乱弧菌分离株的基因特征。2016 年 1 月至 2017 年 12 月期间共收集了 99 株霍乱弧菌。研究进行了多位点可变数串联重复分析以进行遗传相关性分析，并用错配扩增突变分析聚合酶链反应分析毒素基因。使用 Kirby Bauer 圆盘扩散法对所有分离株进行抗菌药物敏感性测试。数据通常使用 Microsoft excel 进行分析，其中遗传相关性使用 eBurst software v3 进行分析。
所有分离株均为霍乱弧菌 O1 型，O1 Ogawa 血清型最为常见（97%，97/99）。分离株具有较小的遗传多样性，与 ctxA、tcpA El Tor 毒力基因呈阳性。所有分离株（100%）对强力霉素、复方磺胺甲噁唑、四环素、头孢曲松和氯霉素敏感，而 87.8%对环丙沙星敏感。对红霉素、萘啶酸、阿莫西林和氨苄西林的耐药率（100%）较高。
O1 血清型霍乱弧菌 Ogawa、El Tor 变体主要引起坦桑尼亚的霍乱暴发，无论暴发地点和时间，菌株均具有克隆相关性。大多数分离株对坦桑尼亚目前使用的抗生素方案敏感。对其他常用抗生素的高耐药率要求在暴发期间持续进行抗菌药物敏感性测试。
