Species composition and methicillin resistance of staphylococci taken on dairy farms

Methicillin-resistant staphylococci can often asymptomatically colonize animals and humans and are capable of causing disease in them. Therefore, their identification and species identification are important for establishing the source of zoonotic infection and the reservoirs of antimicrobial resistance genes. The purpose of the search was to study the spread of methicillin-resistant staphylococci on dairy farms in the Western region of Ukraine. BD Baird-Parker Agar (HiMedia, India) was used to isolate staphylococci. Specific identification of pure cultures was performed using “RapID Staph Plus” kits (Oxord, UK). Staphylococcus sensitivity to methicillin was determined by inoculum application on Muller-Hinton agar with oxacillin (HiMedia, India). The sensitivity of the isolates to antibacterial preparations was determined by disco-diffusion method. The results of our searches show that Staphylococcus aureus is virtually identical in the amount both from cows (50.1 %) and from humans (62.4 %). In this case the frequency of its isolation among other species was 20.3 %. Along with Staphylococcus aureus there are such species as: S. haemolyticus (20.3 %), S. saprophyticus (13.6 %), S. xylosus (14.0 %), S. chromogenes (11.1 %), S. sciuri (8.8 %), S. epidermidis (4.8 %), S. hominis (3.4 %), S. cohnii (2.6 %) and S. warner (0.7 %). In this case, approximately the same irradiation of cows, humans and the environment by species S. haemolyticus (44.5:70.8:58.8 %), S. epidermidis (12.7:16.6:9.1 %), S. xylosus (26.0:37.4:52.9 %) is observed. The share of S. aureus strains on methicillin-resistant dairy farms in the Western Ukraine is 26.8 %. The proportion of S. aureus strains on methicillin-resistant dairy farms in the Western Ukraine is 26.8 %. Methicillin resistance is also shown S. haemolyticus, S. saprophyticus, S. xylosus та S. chromogenes. In this case their number is 1.1, 1.3, 1.6 and 5.5 times lower, respectively, and S. hominis 1.2 times higher than S. aureus. In addition, the selected cultures simultaneously show resistance to two or more antibiotics. Thus, staphylococci circulating on dairy farms are a large reservoir of resistance genes of antimicrobial preparations. Therefore, it is necessary to establish a constant control of the secretion of staphylococci resistant to β-lactam antibiotics.