Microbiological safety of fresh fish infected by trematodes considering the reservoirs sanitary condition

The purpose of research is to study the relationship between the microbiological indicators of fish infected with diplostomosis and post-diplostomosis, and the indicators of veterinary and sanitary safety of water bodies involved in its cultivation. Objectives: determination of the main parasitological indicators of infected fish (intensity of invasion (II), extensiveness of invasion (EI), species predisposition of fish to pathogens of trematodes); conducting a microbiological analysis of the obtained fresh fish and the place of its cultivation, taking into account the degree of infestation of the fish by pathogens of diplostomosis and post-diplostomosis. The study was conducted in the conditions of the North Caucasus Zonal Research Veterinary Institute in the summer and autumn seasons of the year. The study material included fish of different species: Hypophthalmichthys molitrix (silver carp), Cyprinus carpio (carp), Ctenopharyngodon idella (grass carp), Abramis brama (Bream), both infected with trematodes and clinically healthy. The water of the fish catchment site, taken from the Nizhnedonsky canal, Veselovsky, Proletarsky and Tsimlyansky reservoirs, was studied. The lowest AI and EI were found in fish of the species Ctenopharyngodon idella (grass carp). AI in silver carp compared to grass carp was 11.3 times higher, in carp - 9.3 times, in bream - 6.6 times; EI was 11.3 times higher in silver carp and 11.0 times higher in carp; for bream - 3.3 times. In highly invasive fish of the species Hypophthalmichthys molitrix (silver carp), Cyprinus carpio (carp), mesophilic aerobes and facultative anaerobic microorganisms were found to be 14.7 and 4.24 times more, respectively, compared to healthy fish; according to the average value of detected colifoim bacteria - 2.54 and 1.86; by the number of detected Staphylococcus sp. - at 24.3 and 33.15; Escherichia sp. - at 1.5 and 0.6; Klebsiella sp. - at 110 and 85; Salmonella sp. - 45 and 0.8 times more. A correlation was established between the total microbial number of water bodies and the number of mesophilic aerobes and facultative anaerobes in caught live fish (correlation coefficient 0.99).