Indian Journal of Poultry Science

An investigation was conducted on twelve E. coli strains isolated from various poultry farms in and around Hyderabad regions, sourced from carcasses showing lesions of air-sacculitis, perihepatitis and pericarditis. These serotypes were identified as O119, O78, Rough, O54, O73, O132, O115, O89, O111, O61, O20 and O88, based on standard serological typing. These were subjected to three repetitive DNA sequences based Genomic fingerprinting protocols, i.e. REP-PCR, ERIC-PCR and BOX-PCR. Results revealed that each of these repetitive-DNA fingerprints yielded unique DNA profiles for these isolates by which each strain could be discriminated from the other with varying degree of accuracy, with non-overlapping size resolution. Using Dice Similarity Co-efficient and UPGMA, dendrograms constructed for each of the REP-fingerprinting protocols, one could determine the inter-isolate genetic distance and clustering very uniquely, though with minor difference in intra-grouping closeness. The inter-isolate discriminatory power for these 3 PCR protocols was in the order REP-PCR → ERIC-PCR → BOX-PCR. It was concluded that repetitive DNA fingerprinting based protocols can be desirably used in combination of at least two REP-PCR methods (out of the three) as supplementary information to the conventional microbiological methods to identify isolates from an outbreak and to estimate genetic diversities and their clonal relationship.