Abstract

Objective: To study the prevalence of Edwardsiella tarda (E. tarda) in finfish and shellfish of West Bengal and Bihar, India and their antibiogram. Methods: Fish samples were enriched overnight in Edwardsiella ictaluri broth and plated onto Edwardsiella ictaluri agar. Typical colonies were identified conventionally and by VITEK 2 compact system. Antibiogram was done by agar disc diffusion assay. Results: Of the 118 fish samples screened, only 14.41% had E. tarda. The incidence was marginally high in wild fish (15.30%) than in cultured fish (13.26%). Maximum incidence was in intestine (12.98%) followed by gills (6.60%) and skin (2.38%). All E. tarda strains were sensitive to ciprofloxacin and exhibited varying degrees of resistance to other antibiotics. Multiple antibiotic resistance was seen in 84.00%–87.50% of the E. tarda strains. Majority of them had high minimal inhibitory concentration values (200 µg/mL) for oxytetracycline and gentamycin. Conclusions: The results suggested that considerable proportions of commercially important finfish are carriers of multiple antibiotic resistance E. tarda. This calls for proper sanitary measures to eliminate this pathogen in fish and fishery products

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