ANTIBIOTIC SUSCEPTIBILITY OF MYCOPLASMA-BOVIS STRAINS ISOLATED IN NORTHERN-IRELAND

The susceptibility of 23 field strains and four type cultures of Mycoplasma bovis against four antibodies was measured in vitro. the minimal inhibitory concentrations (MICs) for enrofloxacin, lincomycin and spectinomycin were within the ranges of 1 to 2, 0.125 to 2, and 4 to 32 mu g/ml, respectively, against all strains. Nine field strains and three type cultures were inhibited by low levels (<0.06 to 0.5 mu g/ml) of tilmicosin, while 14 field strains and one type culture were more resistant, being inhibited within the range of 4 to >32 mu g/ml. Enrofloxacin was the only antibiotic which exhibited any measurable mycoplasmacidal activity.