Isolation of Faecal Enterococcus Faecium Strains from Rabbits and Their Sensitivity to Antibiotics and Ability to Bacteriocin Production

Faecal samples from 23 rabbits of various age from 5 different rabbit flocks were examined for the presence of enterococci. Fifty-eight strains of Enterococcus sp. enumerated in the range from 10 to 10 CFU/mL were genotyped using PCR followed by agarose electrophoresis. Fifty percent of the isolates identified as Ent. faecium were tested for sensitivity to antibiotics and bacteriocin production. Among these isolates all were resistant to novobiocin, 93.1% to kanamycin and 82.8% to streptomycin, erythromycin and vancomycin. Six strains (EF 2019, EF 2119, EF 1819, EF 1839, EF 529, EF 24) showed antilisterial effect as well as the activity against indicator strain Ent. avium EA 5 by the testing of the bacteriocin activity. Bacteriocin substance produced by the most active Ent. faecium EF 2019 strain was partially purified reaching inhibitory activity 6400 AU/mL against indicator strain Ent. avium EA 5.