الكاتب: Multiple References

Coryneform bacteria are frequently isolated from bovine mastitis (2, 6, 7). In a previous study, the lipophilic species, Corynebacterium bovis and Corynebacterium amylocolatum were the most frequently isolated coryneform organisms (10). Antibiotic therapy is an essential component of mastitis control programs, and the accurate selection of the most effective antimicrobial agents depends upon the susceptibility of the organism to the agent. The purpose of this study was to determine the susceptibility of C. bovis and other coryneforms isolated from bovine mastitis to various antimicrobial agents. Forty-six strains of C. bovis and 13 strains of C. amylocolatum from a previous study were used (10). Prior to the MIC determinations, all isolates were revived by subculture on Trypticase soy agar (Becton Dickinson Microbiology Systems, Cockeysville, Md.) supplemented with 5% sheep blood and 1.0% Tween 80 and incubated for 24 h at 35 to 37°C. MICs were determined using a broth microdilution method (Sensititre, Westlake, Ohio), except that the Mueller-Hinton broth was supplemented with 1% Tween 80 (6, 10). The MIC panel contained the following antimicrobial agents: ampicillin, oxacillin, cephalothin, ceftiofur, penicillin plus novobiocin, erythromycin, clindamycin, pirlimycin, tilmicosin, florfenicol, tetracycline, enrofloxacin, sarafloxacin, danofloxacin, and premafloxacin. The NCCLS-recommended quality control strains were included with each batch of organisms tested.