occurence of antibiotic resistant enterococci on skin of teats and teat cups of milking machine

The production of high-quality milk with low bacteriological counts begins at the farm and involves multiple factors related to cows, environment, and hygiene of equipment. The aim of this study was to investigate the occurrence of enterococci in conditions of farmhouse production and antibiotic resistance of 49 strains isolated from skin of teats and 50 strains isolated from teat cups of milking machine. The samples for enumeration and isolation of enterococci were cultured on selective diagnostic Slanetz-Bartley agar. The isolates were phenotypically identified at the species level with EN-COCCUS test. Susceptibilities of isolated enterococci to antibiotic (vancomycin 30 μg/disc, ampicillin 10 μg/disc, erythromycin 15 μg/disc, gentamicin 120 μg/disc, teicoplanin 30 μg/disc and tetracycline 30 μg/disc) were tested using the disc diffusion method.  The counts of enterococci from teats reached the average value 2.77 log₁₀ cfu.ml^-1 and from teat cups of milking machine average value 2.85 log₁₀ cfu.ml^-1. The dominant species isolated from teats (41%) and also from teat cups (36%) were representatives of E. group III - E. durans, E. hirae, E. faecalis asaccharolytic var. The isolates of enterococci obtained from teats showed resistance to tetracycline (4%), erythromycin (4%) and intermediary resistance to tetracycline (8%), erythromycin (25%) and to vancomycin (8%). The isolates of enterococci obtained from teat cups showed resistance to tetracycline (2%) and intermediary resistance to erythromycin (20%) and to vancomycin (6%). No resistance to the antibiotic teicoplanin, ampicillin and gentamicin was found. The most of the isolates of enterococci were sensitive to the tested antibiotics.