ANTIMICROBIAL SUSCEPTIBILITY OF MORAXELLA-BOVIS

The antimicrobial susceptibility of 55 isolates of Moraxella bovis to seven antibiotics was evaluated by broth microdilution procedures. The isolates had an MIC90 of less than or equal to 1 mg/l to erythromycin , ceftiofur, and ampicillin; 4 mg/l to tilmicosin; 16 mg/l to tylosin and gentamicin; and had MIC(90)s of greater than or equal to 32 mg/l f or oxytetracycline. The modal MIC values for these antibiotics were as follows: ampicillin, <0.25 mg/l; ceftiofur, <0.125 mg/l; tilmicosin, 2 mg/l; tylosin, 8 mg/l; erythromycin 1 mg/l; oxytetracycline, less th an or equal to 0.5 mg/l; and gentamicin, <0.5 mg/l. This in vitro data showed most antibiotics have low MICs that are suggestive of clinical efficacy. (C) 1998 Elsevier Science B.V.