IN-VITRO ANTIMICROBIAL SUSCEPTIBILITY OF CLOSTRIDIUM-PERFRINGENS FROMCOMMERCIAL TURKEY AND BROILER CHICKEN ORIGIN

The minimum inhibitory concentrations (MIC) of eight antibiotics and t wo anticoccidial agents were determined for Clostridium perfringens st rains isolated from 26 commercial broiler farms and 22 commercial turk ey farms. Isolates were obtained from the intestines of birds on the f arm or at the processing plant using standard culture and identificati on techniques. The microbroth dilution test was used to determine the MIC for each compound. Most isolates from chickens had MICs in the ran ge of 2-16 mg/L for tilmicosin, tylosin and virginiamycin, whereas the MICs for avilamycin, avoparcin, monensin, narasin and penicillin were less than or equal to 1 mg/L. Most strains from chickens had high MIC s (greater than or equal to 64 mg/L) and appeared to be resistant to b acitracin and lincomycin. Most turkey isolates had MICs in the range o f 2-16 mg/L for bacitracin, tilmicosin, tylosin and virginiamycin, wit h strains exhibiting MICs less than or equal to 1 mg/L for avilamycin, avoparcin, monensin, narasin and penicillin, Several turkey isolates had MICs greater than or equal to 64 mg/L to lincomycin. No attempt wa s made to associate farm usage of a particular antibiotic to the antib iograms.