Detection of Vibrio cholerae and Vibrio parahaemolyticus by molecular and culture based methods from source water to household container-stored water at the point-of-use in South African rural communities

摘要

Detection methods for Vibrio cholerae and Vibrio parahaemolyticus which included the culturenbased approach with polymerase chain reaction (PCR) confirmation, PCR detection withoutnenrichment and PCR with a pre-enrichment were developed and their performance evaluated.nPCR assays targeted the SodB (V. cholerae species), Flae (V. parahaemolyticus species), 16S rRNAn(Vibrio and Enterobacteriacea species) genes (Multiplex 1) and V. cholerae O1 and V. choleraenO139 rfb genes, ctxA (cholera toxin) gene and 16S rRNA gene (Multiplex 2). These methods werenused to determine the occurrence of selected Vibrios in source water as well as in householdncontainer-stored water. The combination of filtration, enrichment and PCR method providedna sensitive and specific method for the detection of selected Vibrios in water samples.nThe PCR with a pre-enrichment method detected as few as 4–10 cfu/100mL of selected Vibriosnand PCR detection without the enrichment method detected as few as 40–100 cfu/100mLnof selected Vibrios. The inclusion of an enrichment period allows detection of culturablenbacteria. As an application of the developed methods, V. cholerae and V. parahaemolyticusnwere detected in the source water used by the population and in the water-storage containers.nThe results indicate that Vibrio species in the containers could have originated from the sourcenwater and survive in biofilms inside the containers.