[Studies on the method of susceptibility test of Campylobacter jejuni to fosfomycin]

Conditions for the susceptibility test of Campylobacter jejuni to fosfomycin (FOM) were studied and it was concluded that the following procedure is most appropriate for routine tests. The test organisms were subcultured in 0.5 ml of heart infusion broth (Difco) in test tubes for a microplanter (Sakuma Seisakusho) and incubated in a GasPak jar with a CampyPak and catalyst (BBL) at 37 degrees C for 44--48 hours. The cultures were then diluted 100-fold in the same broth and inoculated with a microplanter on test plates. The test plates were nutrient agar (Difco) supplemented with 0.2% MgCl2 and 5% defibrinated horse blood. The plates were then incubated under the condition as described above and the growth of the cells was examined. It should be noted that drying of plates for more than 1 hour caused significant loss of viability of the cells.