Antibiotic Resistance Patterns of Escherichia coli and Salmonella from Environmental Samples of Thoothukudi Coast

Abstract

The incidence and antibiotic resistance pattern of E. coli and Salmonella from water, beach sand and fish collected from four fish landing centres of Thoothukudi were studied. Presence of £. coli was confirmed in 90%, 92% and 79% of water, beach sand and fish samples respectively, while Salmonella was detected in 25% of water and sand samples and 17% of fish samples. The isolates were tested against fifteen antibiotics by disc diffusion method. While all the E. coli isolates were resistant to bacitracin, erythromycin and rifampicin, none of the isolates was resistant to ampicillin, chloramphenicol and sulphafurazole. Among Salmonella isolates, all were resistant to bacitracin and most were resistant to ampicillin, colistin, erythromycin and rifampicin. None of the Salmonella isolates was resistant to chloramphenicol, ciprofloxacin and norfloxacin. Multiple antibiotic resistance (MAR) index was higher than 0.2 in all strains of E. coli and Salmonella revealing that they might have originated from high-risk sources of contamination such as humans.