Antibiotic Resistance of Microbiotas of Fishery Enterprises Hydro Ecosystems

Abstract

The aquatic environment is an integral part of biocenosis that directly affects its condition and safety in terms of epidemiology and epizootology. The study of the aquatic environment for the presence of pathogens and the quantitative characteristics of sanitary-indicative microorganisms is extremely important. The obtained data allow us to assess and predict the risks of infections, and to develop a plan of measures to prevent the spread of certain pathogens. The aim of the work. To analyze the microbial state of the aquatic environment in different hydro ecosystems of fish farms in the Kharkiv region and to assess the presence of microbiological risks to public health. Methods. The research objects were 150 samples of water taken from different hydro ecosystems in the Kharkiv region. Water was taken from closed water supply systems (n=30) and from ponds (n=120), where commercial fish is bred for sale. The presence and number of sanitary-indicative microorganisms and pathogenic bacteria were determined by the bacteriological (cultural) method. Resistances to antibacterial drugs in selected sanitary-indicative microorganisms were determined using the Agar disk-diffusion method. Estimation of the reliability of the difference between the compared indicators was determined using Student’s t-test. Results. The dominant sanitary-indicative microorganisms in the aquatic environment of fish farming were bacteria of the genus Citrobacter spp., Aeromonas spp., and Pseudomonas spp. The total bacterial contamination of water bodies ranged from 1.9±0.50×104 to 2.1±1.20×105 CFU in 1 cm3 of water. No pathogenic to humans bacteria have been detected. Isolated sanitary-indicative microorganisms had significant resistance to antibacterial drugs. Resistance to penicillins, sulfonamides, and nitrofurans was the highest (p=0.0001). The percentage of penicillin resistance strains ranged from 81.5% to 87.0%, sulfonamide — from 74.1% to 94.4%, and nitrofuran — from 55.5% to 66.7%. Fluoroquinolone and cephalosporin resistance varied depending on the type of antibacterial substance, but it did not exceed 29.6%. Conclusions. According to the research results for the aquatic environment of fish farms in the Kharkiv region, no pathogenic microorganisms were detected. However, it has been established that sanitary-indicating microorganisms (Citrobacter spp., Aeromonas spp., Pseudomonas spp.), which were dominant and had polyresistance to antibacterial drugs, may be risk factors for human health. Thus, the hydro ecosystems of fish farms have favorable conditions for the accumulation of bacterial strains resistant to antibiotics. Therefore, the use of antibacterial drugs should be scientifi cally justifi ed and strictly controlled.