Dalusi Lucy, Lyimo Thomas J, Lugomela Charles, Hosea Ken M M, Sjöling Sara
Amana Regional Referral Hospital, P.O. Box 25411, Dar es Salaam, Tanzania Department of Molecular Biology and Biotechnology, University of Dar es Salaam, P.O. Box 35179, Dar es Salaam, Tanzania.
Department of Molecular Biology and Biotechnology, University of Dar es Salaam, P.O. Box 35179, Dar es Salaam, Tanzania
FEMS Microbiol Lett. 2015 Mar;362(5). doi: 10.1093/femsle/fnv009. Epub 2015 Jan 23.
The current study assessed the occurrence of the Vibrio cholerae serogroups O1 and O139 in environmental samples along salinity gradients in three selected estuaries of Tanzania both through culture independent methods and by cultured bacteria. Occurrence of V. cholerae was determined by PCR targeting the V. cholerae outer membrane protein gene ompW. Furthermore, the presence of toxigenic strains and serogroups O1 and O139 was determined using multiplex PCR with specific primers targeting the cholera toxin gene subunit A, ctxA, and serotype specific primers, O1-rfb and O139-rfb, respectively. Results showed that V. cholerae occurred in approximately 10% (n = 185) of both the environmental samples and isolated bacteria. Eight of the bacteria isolates (n = 43) were confirmed as serogroup O1 while one belonged to serogroup O139, the first reported identification of this epidemic strain in East African coastal waters. All samples identified as serogroup O1 or O139 and a number of non-O1/O139 strains were ctxA positive. This study provides in situ evidence of the presence of pathogenic V. cholerae O1 and O139 and a number of V. cholerae non-O1/O139 that carry the cholera toxin gene in estuaries along the coast of Tanzania.
本研究通过非培养方法和培养细菌的方式，评估了坦桑尼亚三个选定河口沿盐度梯度的环境样本中霍乱弧菌O1和O139血清群的出现情况。通过针对霍乱弧菌外膜蛋白基因ompW的PCR来确定霍乱弧菌的出现情况。此外，使用多重PCR分别针对霍乱毒素基因亚基A（ctxA）的特异性引物以及血清型特异性引物O1-rfb和O139-rfb，来确定产毒菌株以及O1和O139血清群的存在情况。结果显示，环境样本和分离出的细菌中约10%（n = 185）含有霍乱弧菌。43株细菌分离物中有8株被确认为O1血清群，1株属于O139血清群，这是在东非沿海水域首次报告鉴定出这种流行菌株。所有被鉴定为O1或O139血清群的样本以及一些非O1/O139菌株的ctxA均呈阳性。本研究提供了原位证据，证明坦桑尼亚沿海河口存在致病性霍乱弧菌O1和O139以及一些携带霍乱毒素基因的非O1/O139霍乱弧菌。
