Characterization and antibiotic resistance patterns of bacteria from fish products retailed at various markets in Kirinyaga County, Kenya

Abstract

Ensuring safe aquaculture products has been one of the major  challenges and concerns for many fish farmers, traders and consumers in developing countries. This is attributed to contamination of fish and fish products by pathogenic and spoilage micro-organisms that are resistant to multiple antibiotics. Additionally, the use of antibiotics in fish farming for prophylaxis has resulted in the transfer of antibiotic-resistant genes thus establishing a reservoir for resistant microorganisms.
Objectives: This study was carried out to determine the level of microbial contamination of fish products and antimicrobial resistance patterns of the isolated bacteria to commonly used antibiotics.
Design and setting: Fish products were sampled from fish traders in six markets from Kirinyaga County. The bacteria cultures were enumerated and sub-cultured to obtain pure cultures used to describe their morphological and biochemical characteristics. The Kirby-Bauer agar diffusion technique was used to carry out the antibiotic susceptibility testing.
Results: Based on morphological characteristics, a total of 59 morpho-groups were obtained and were confirmed by biochemical characterization. There was a significant difference (p = 0.001) and interaction (p = 0.037) of average bacteria count obtained from different fish products. Processed fish resulted to a significant difference (p = 0.001) on mean for CFU. Ciprofloxacin was the most effective antibiotic while about 80 % of the isolates showed multidrug resistance.
Conclusion: The study suggests that fish and fish products harbour multi-resistant bacterial isolates that can aid in the dissemination of resistance genes.