Methodology for compiling a microbial resistance passport for dairy farms

Abstract

Abstract. The article presents the results of the work, the purpose of which was to create a microbial resistance passport for a dairy farm. Methods. Conducted studies of opportunistic pathogenic microflora in various technological areas, there were taken samples of feed, water, air, bedding, washings from the wool and mucous membranes of cows and calves, washings from surfaces, fences, technological equipment, and livestock care equipment. There were determined the frequency of occurrence and the proportion of microorganisms in the structure of the opportunistic microbiocenosis. Results. It was found that on all surveyed dairy farms, the nucleus of opportunistic microbiocenosis was represented by Ent. faecium, Ent. faecalis, S. aureus, S. epidermidis, S. saprophyticus, P. aeruginosa, P. vulgaris, P. mirabilis, Echerichia coli, Aspergillus spp. and C. albicans – the frequency of occurrence of these microorganisms in samples exceeded 15 %. We studied the two-year dynamics of the microbiocenoses composition on farms. It was found that the main nucleus of the microbiocenosis remained stable in species composition, and the percentage of stocks was subject to slight changes. There were carried out he studies of the sensitivity of all detected stocks to antibiotics, based on the results of which were compiled resistances profiles, methods were developed for the analysis of general indicators of microbial resistance throughout the enterprise and in individual technological areas, and were established the ways of spreading resistant stocks on the farm. On the basis of four criteria, including the effectiveness of the antibiotic against the target microorganism, the effectiveness against the non-target microorganism in vitro, the degree of growth inhibition, the minimum inhibitory concentration, the antibiotic susceptibility analysis of the main pathogenic microorganisms was carried out in points. The results obtained were used to predict the expected effectiveness of antibiotics in different technological areas of the farm. The novelty of the researches is in the development of an algorithm for compiling a passport of microbial resistance of a dairy farm, which includes analysis of opportunistic microbiocenosis, analysis of antibiotic sensitivity of microorganisms and prediction of the expected effectiveness of antibacterial drugs.