Specifi c composition of microfl ora circulating at the FARM “Quant System” and its resistance to antibacterial medicines

Abstract

Accumulation of opportunistic pathogenic bacteria in the aquatic environment may lead to the changes in the structure of the surface cover microbiocenosis as well as the fish intestinal tract. In its turn, it causes the growth of pathological processes in the fish organism, reduces the barrier functions of tissues and mucus and, as a consequence, may induce the spread of bacterial infections. Thus, assessing the state of fish organism, it is necessary to take into account the analysis of the epizootic situation in water (i.e. presence of infectious and invasive diseases of fish, death of fish) as well as condition of the skin, gills and gastrointestinal tract. The results of bacteriological studies of washes from the skin, gills and intestines showed that in the conditions of farming among rainbow trout of different age groups, E. coli, low fermented E. coli, Enterobacter spp., Klebsiella pneumoniae, Staphylococcus spp., Flavibacterium spp., Enterococcus spp. and Citrobacter spp. For the purposes of determining the sensitivity of isolated cultures to antibacterial drugs, it was found that Enterobacteriaceae are sensitive to enrofloxacin, cotrimoxazole, doxacillin, chloramphenicol, gentamicin, ceftriaxone, cefoperazone, ceftazidime and cefpiromycin and resistant to oxytetracycline, amoxicillin and ampicillin sulbactam. E. coli also demonstrated resistance to amoxicillin and cefpirome and sensitivity to enrofloxacin, oxytetracycline, cotrimoxazole, doxacillin, chloramphenicol, ampicillin sulbactam, gentamicin, ceftriaxone, cefoperazone, ceftazidime. Klebsiella pneumoniae was resistant to enrofloxacin, amoxicillin and ampicillin sulbactam, while Flavobacteriaceae were resistant to amoxicillin and ampicillin sulbactam and sensitive to all other antibacterial drugs. Key words: rainbow trout, microflora, skin, gills, intestines, antibacterial agents, resistance, sensitivity.