Introduction: The aim of the study was to evaluate the occurrence of enterococci in inflammatory secretions from mastitic bovine udders and to assess their antimicrobial resistance. Material and Methods: A total of 2,000 mastitic milk samples from cows were tested in 2014–2017. The isolation of enterococci was performed by precultivation in buffered peptone water, selective multiplication in a broth with sodium azide and cristal violet, and cultivation on Slanetz and Bartley agar. The identification of enterococci was carried out using Api rapid ID 32 strep kits. The antimicrobial susceptibility was evaluated using the MIC technique. Results: Enterococci were isolated from 426 samples (21.3%). Enterococcus faecalis was the predominant species (360 strains), followed by E. faecium (35 isolates), and small numbers of others. The highest level of resistance was observed to lincomycin, tetracycline, quinupristin/dalfopristin (Synercid), erythromycin, kanamycin, streptomycin, chloramphenicol, and tylosin. Single strains were resistant to vancomycin and ciprofloxacin. All isolates were sensitive to daptomycin. E. faecalis presented a higher level of resistance in comparison to E. faecium, except to nitrofurantoin. Conclusion: The results showed frequent occurrence of enterococci in mastitic cow’s milk and confirmed the high rate of their antimicrobial resistance.

The aim of the study was the evaluation of the antimicrobial resistance of Enterococcus faecalis strains isolated from cattle, pig, and poultry meat. A test was performed on 111 strains using the minimum inhibitory concentration technique. The highest number of isolates (94 strains) were resistant to lincomycin, the second-highest resistance was to quinupristin/dalfopristin (88 strains), tetracycline followed (65 strains), and erythromycin resistance was also notable (40 strains). All isolates tested were sensitive to daptomycin, nitrofurantoine, and tigecycline, whereas only few strains were resistant to ciprofloxacin, gentamicin, penicillin, and vancomycin. The obtained results showed that meat may be a source of antimicrobial resistant enterococci which may be transferred to humans.