Abstract
The determination of antimicrobial minimum inhibitory concentration (MIC) in Erysipelothrix rhusiopathiae by using the agar dilution method has not been covered by the Clinical and Laboratory Institute (CLSI). Only micro-broth dilution method has been outlined. This report describes a modification of the agar dilution procedure for E. rhusiopathiae using Trypto-soy agar supplemented with 0.1% Tween 80 and incubation in ambient air at 37℃ for 24 hr. The MICs of the assay were in agreement with those of the micro-broth dilution method recommended by the CLSI. Antimicrobial susceptibility test was performed using this method for 149 E. rhusiopathiae isolates from two meat processing plants in Kagoshima prefecture during the period from April 2004 to March 2005. The number of resistant strains to oxytetracycline, erythromycin, lincomycin, ofloxacin and enrofloxacin were 56 (37.6%), 4 (2.7%), 18 (12.1%), 21 (14.1%) and 19 (12.8%), respectively. All strains were susceptible to ampicillin.
