Quantification of the Coliform Bacteria and Detection of Enterovirulent Escherichia coli Strains Using Strain Specific genes in Shrimp Farms.

Abstract

Total coliform indicates the presence of Citrobacter spp., Enterobacter spp., Escheriechia spp., Klebsiella spp., Salmonella spp., Shigella spp. and Vibrio spp. In Bangladesh, traditional shrimp culture farms are highly susceptible to contamination with pathogenic bacteria because of poor sanitation near to these farms. The aim of the present study was to quantify total coliform and detect enterovirulent groups (EHEC,  nterohaemorrhagic, EPEC, enteropathogenic and ETEC, enterotoxigenic) of E. coli in shrimp farms in winter and summer seasons at Khulna district of Bangladesh. All the farms were contaminated with coliform but E. coli was present only in 55% farms. In winter season, average number of coliform and E. coli in hygienic farms were 4.94×102  (cfu/mL) and nil whereas that in unhygienic farms were 8.17×102 (cfu/mL) and  4.15×102 (cfu/mL), respectively. However, in summer, the number of coliform and E. coli in hygienic farms were 8.26×103  (cfu/mL) and 8.51×102 (cfu/mL) whereas that in unhygienic farms were 1.11×104  (cfu/mL) and 4.52×103 (cfu/mL), respectively. Using cultural, biochemical and PCR techniques, 76 E. coli were identified. Among them, EPEC and ETEC groups were 22% and 29%, respectively whereas EHEC group was absent. The results of this study revealed that water contaminated in shrimp farms of Khulna district resulted from insufficient sanitation that represent unhygienic products.