Antimicrobial Susceptibility of Mycoplasma hyorhinis in a Liquid Medium Compared to a Disc Assay

Abstract

Mycoplasma hyorhinis is a common cause of infections in swine (Kobisch & Friis 1996) and antimicrobial agents are sometimes used for treatment of the infections. Isolates with decreased susceptibility to macrolides have been reported (Kobayashi et al. 1996), but only a very limited number of studies on the susceptibility of M. hyorhinis to antibiotics has been reported. There are at present no international guidelines for susceptibility testing or interpretation of isolates as being resistant or susceptible, but problems in and methods for susceptibility testing have previously been discussed (Kenny 1996, Bébéar & Robertson 1996). The present study was conducted to examine the inhibitory effect of some commonly used antimicrobials on M. hyorhinis using both determination of Minimal Inhibitory Concentration (MIC) in liquid medium and a disc diffusion test on solid medium.