Estimation of microbial conatmination in different sea fishes and implementation of time-dependent UV-radiation to control the existence of fish microflora

Abstract

The present study attempted to evaluate the existence and survival of microorganisms in common sea fishes available in Bangladesh and also evaluated the effects of UV radiation (260 nm) to reduce the proliferation of bacterial pathogens. A total of 12 categories of sea fishes were collected from local markets in Dhaka city of Bangladesh. Each sample was subjected to UV-irradiation at different time intervals such as 5 min, 10 min & 15 min. The bacterial existence and drug susceptibility pattern of the isolates were determined through the conventional cultural techniques, biochemical identification, and disc diffusion method, respectively. Most of the raw fish samples were found to be contaminated with huge number of microorganisms including the coliforms (E. coli and Klebsiella spp.), Salmonella spp., Shigella spp., Staphylococcus spp., Pseudomonas spp. and Vibrio spp. Moreover, the identified isolates were found to be resistant to single or multiple commercially available antibiotics. The incidence of coliforms and other harmful bacteria along with their drug-resistance traits may be considered a serious threat to the public health upon consumption of such fishes. When subjected to UV-irradiation, the propagation rate of pathogens was significantly reduced, in many cases 100% reduction was observed, especially after 15 min of UV radiation.