MIC test of Campylobacter jejuni/coli

Abstract

Using 3 kinds of medium, Mueller-Hinton (M-H) agar, M-H agar added with defibrinated horse blood and lysed horse blood, susceptibilities of Campylobacter were tested quantitatively to 12 antibacterial agents. The result showed no remarkable difference between them. MIC was examined with the cell concentration of McFarland unit 0.5 and 100-times dilution, and there was no significant difference between them except for 2 strains, on which erythromycin showed MIC of 6.25 micrograms/ml at McFarland unit 0.5 and 0.39 micrograms/ml at 100-times dilution. Eighty-two clinical isolates of C. jejuni and 6 of C. coli were tested for their susceptibility to 12 antibacterial agents. These strains were most susceptible to gentamicin and amikacin and less susceptible to benzylpenicillin, carbenicillin and cephaloridine with the MIC of 25 micrograms/ml. There were 2 peaks of susceptibility distribution to minocycline (0.2 and 50 micrograms/ml). In tests for beta-lactamase of C. jejuni and C. coli, 3 strains obtained from 1 patient were positive.