Toxigenic Vibrio cholerae identified in estuaries of Tanzania using PCR techniques.
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.
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.
Lucy
L
Dalusi
Department of Molecular Biology and Biotechnology, University of Dar es Salaam, P.O. Box 35179, Dar es Salaam, Tanzania tjlyimo@udsm.ac.tz.
Thomas J
TJ
Lyimo
Department of Aquatic Sciences and Fisheries, University of Dar es Salaam, P.O. Box 35064, Dar es Salaam, Tanzania.
Charles
C
Lugomela
Department of Molecular Biology and Biotechnology, University of Dar es Salaam, P.O. Box 35179, Dar es Salaam, Tanzania.
Ken M M
KM
Hosea
Department of Natural Sciences, Technology and Environmental Studies, Sodertorn University, 141 89 Huddinge, Sweden.
Sara
S
Sjöling
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002772:Cholera Toxin / Q000235:genetics; D017931:DNA Primers; D063366:Estuaries; D005798:Genes, Bacterial; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D013636:Tanzania; D041241:Vibrio cholerae O1 / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D041242:Vibrio cholerae O139 / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics; D014871:Water Microbiology
D001425:Bacterial Outer Membrane Proteins; D017931:DNA Primers; D002772:Cholera Toxin
East Africa; Tanzania; Vibrio cholerae; cholera; estuaries; sediment