ADAPTATION OF THE SENSITITRE(R) BROTH MICRODILUTION TECHNIQUE TO ANTIMICROBIAL SUSCEPTIBILITY TESTING OF MYCOPLASMA-HYOPNEUMONIAE

A broth microdilution technique is described for determining the antim icrobial susceptibility of Mycoplasma hyopneumoniae, using commerciall y prepared Sensititre(R) plates. Twenty-five field isolates and two re ference strains (J & 232), were tested against seven antimicrobials. F ield isolates were tested in duplicate and reference strains, four tim es to estimate reproducibility. Ninety-seven percent of the duplicate MIC results for the field isolates were in agreement, or within one lo g, dilution. Similar results were obtained with the reference strains. The isolates were susceptible to lincomycin-spectinomycin, tylosin an d oxytetracycline or resistant to amoxycillin, apramycin and erythromy cin. Susceptibility to furaltadone varied. This method retains the acc uracy and reproducibility of broth MIC determinations, while avoiding the lengthy preparation of antimicrobial dilutions normally associated with more traditional methods.