Enterococcus species isolated from sheep milk and Slovak Bryndza cheese and their antibiotic susceptibility

The aim of this study was to determine the occurrence and antibiotic susceptibility of enterococci in raw sheep milk and in Bryndza cheese. The average count of enterococci in the samples of sheep milk (n=61) reached the value of 4.82 log cfu.ml(-1), in the samples of Bryndza cheese (n=1 8) 6.12 log cfu.g(-1). Enterococci isolated from sheep milk (n=60) were identified as E. faecalis (70 %) and E. faecium (30 %). In Bryndza cheese, 50 enterococcal strains were isolated and the following species were identified: E. faecalis (46 %), E. faecium (46 %) and Enterococcus sp. (8 %).Susceptibility of enterococci to antimicrobial agents was tested using the disc diffusion method. All tested enterococci were sensitive to vancomycin. The resistance rates of enterococci isolated from sheep milk to ampicillin, erythromycin, gentamicin and tetracycline were 16.67, 1.67, 31.67 % and 31.67 %, respectively. Three strains of E. faecalis isolated from sheep milk exhibited multi-drug resistance to ampicillin, gentamicin and tetracycline. Among the enterococci isolated from Bryndza cheese, 14 % strains were resistant to ampicillin, 6 % to erythromycin and 14 % to gentamicin, but were not resistant to tetracycline.