Molecular Approach in Detection of Enterovirulent Escherichia coli Strains from Traditional Shrimp Farms of Bangladesh

Abstract

DOI: 10.20286/ajlsr-040288 This study was conducted to detect the presence of enterovirulent Escherichia coli strains using PCR technique in some selected unhygienic and hygienic traditional shrimp farms in Bangladesh. The target genes chosen for this investigation included: the phoa housekeeping gene (present in all E. coli ); the lt1, lt2 and st1 genes of ETEC; the vtverotoxin, and eae virulence genes of EHEC and EPEC, respectively. Six pairs of oligonucleotide primers were designed to amplify internal fragments of these genes by PCR to generate PCR products that were analyzed by gel electrophoresis. The presence of E. coli strains were determined by visualization of strain specific band comparing with a 100 bp DNA size marker in UV transilluminator. The results revealed that water of both hygienic and unhygienic farms were highly contaminated with E. coli followed by sediment and shrimp. Whereas, only water, sediment and shrimp of unhygienic farms were found to be contaminated with virulent E. coli strains. Among the virulent E. coli strains, ETEC and EPEC strains were detected in unhygienic farms, but no EHEC strain was detected. However, no contamination with virulent E. coli strains was found in hygienic farms.