In vitro antibiotic susceptibility of field isolates of Mycoplasma hyopneumoniae and Mycoplasma hyorhinis from Korea

The present study was conducted to determine the antibiotic susceptibilities of local Mycoplasma hyopneumoniae (Mhp) and Mycoplasma hyorhinis (Mhr) filed isolates. Minimum inhibitory concentrations (MICs) of Mhp and Mhr field isolates (twelve each) obtained from enzootic pneumonia-like lung lesions during 2009-2011 from Korea were determined using the broth microdilution method. Tylvalosin showed the highest activity against Mhp and Mhr field isolates, with MIC90 values of 0.06 µg/mL and 0.12 µg/mL, respectively. Therefore, Korean Mhp and Mhr isolates are highly susceptible to tylvalosin.