Assessment of Bacterial Contamination and Antibiotic Resistance Patterns among Escherichia coli in Finfishes of Kolkata, India

Abstract

Bacterial contamination and safety of finfishes of commercial importance and the frequency of antibiotic resistance in Escherichia coli in fishes of Kolkata retail markets were evaluated. Finfishes available in the retail markets recorded high levels of total viable counts (4.30-7.93 log cfu g-1), coliforms (1.60-4.38 log MPN g-1), faecal coliforms (£4.38 log MPN g-1) and E. coli (£4.04 log MPN g-1). Majority of the E. coli was resistant to oxytetracycline (73%) and exhibited multiple antibiotic resistance (52%). Mutation frequencies to oxytetracycline were higher (1.3x10-9– 7.3x10-4) compared to chloramphenicol (4.6x10-8– 6.8x10-8). Seven serotypes were recorded, of which O-type 95 was the most common. Shiga-like toxinproducing E. coli serotypes such as O2, O22 and O114 were recorded. The results revealed that most of the commercially important fishes did not meet the national and international quality standards and were contaminated with antibiotic resistant and shiga-like toxin-producing E. coli, which represent a health risk to the consumers.