ANTIBIOTIC SENSITIVITY OF BACTERIA ISOLATED FROM NILE TILAPIA (Oreochromis niloticus) FISH FROM GAZIPUR FISH MARKET

ABSTRACT: Nile tilapia (Oreochromis niloticus) is extensively cultured in Bangladesh. The objective of this study was to detect the health hazard microbes (Vibrio cholerae, Salmonella spp., Escherichia coli and other pathogenic bacteria) in Nile tilapia fish and their sensitivity against the antibiotics. Total plate count (TPC) of bacteria, E. coli count, presence/absence of Salmonella, Vibrio and antibiotic sensitivity test of the isolated bacteria were done by the standard microbiological method. The highest TPC was 4.995 Log 10 CFU/g, and the lowest was 4.822 Log10 CFU/g. E. coli ranged from 2.462 Log10 CFU/g to 2.903 Log10 CFU/g. The TPC value showed insignificantvariations and almost all were within the acceptable limit range. No Salmonella and Vibrio cholerae were found. Escherichia coli were found in seven samples, Leclercia adecarboxylata were found in six samples, and P. alimentorum was found in six samples. Seven antibiotics were used for antibiotic resistance testing, and isolated bacteria mostly showed resistance toward ampicillin, and only four isolates showed resistance to nitrofurantoin and oxytetracycline. The highest sensitivity found for ciprofloxacin. Results of the study indicate that pathogenic bacteria are present in retail tilapia fish, and some are resistant to antibiotics. Consumers in Gazipur are at risk regarding for antibiotic resistance of tilapia. 

Keywords: Oreochromis niloticus, Total plate count, Escherichia coli, Leclercia adecarboxylata, Proteus alimentorum, antibiotic sensitivity