Molecular Epidemiology of Escherichia coli from Cochin Estuary

In this book, we investigated prevalence of different serotypes, phylogenetic groups, antibiotic resistance, antibiotic resistance genes (ARGs), and extraintestinal virulence genes of Escherichia coli isolates from a tropical estuary in the south-west coast of India. A total of 300 E. coli strains were isolated from five different stations in Cochin estuary during a period from June 2009 to February 2013. A total of 225 water samples were analysed for faecal coliforms by MPN method. Biochemically confirmed E. coli cultures were serotyped at National Salmonella and Escherichia Center, Central Research Institute, Kasauli, Himachal Pradesh, India. Molecular identification of E. coli was done by the amplification of uidA gene. Phylogenetic grouping of E. coli isolates was determined by a triplex PCR method. Prevalence of antibiotic resistance among E. coli isolates was determined by disc diffusion method and multiple antibiotic resistance (MAR) indexing. E. coli isolates were also analyzed for the presence of ARGs (blaTEM, blaCTX-M, tetA, tetB, sul1, sul2, dhfr1, dhfr7, strA, aphA2, and catI) and extraintestinal virulence genes (papAH, papC, sfa/focDE, kpsMT II, and iutA) by PCR.