Analysis of the mutant selection window and killing of Mycoplasma hyopneumoniae for doxycycline, tylosin, danofloxacin, tiamulin, and valnemulin

• DOI: 10.1371/journal.pone.0220350
• Publication Date: 2020-06-16T17:37:56Z
• Authors: Zilong Huang; Chunxiao Mao; Yanzhe Wei; Xiaoyan Gu; Qinren Cai; Xiangguang Shen; Huanzhong Ding
• Keywords: Mycoplasma hyopneumoniae; Tiamulin; Tylosin; Danofloxacin; Agar dilution; Broth microdilution

Mycoplasma hyopneumoniae is the major pathogenic microorganism causing enzootic pneumonia in pigs. With increasing resistance of M. to conventional antibiotics, treatment becoming complicated. Herein, we investigated mutant selection window (MSW) doxycycline, tylosin, danofloxacin, tiamulin, and valnemulin for treating type strain (ATCC 25934) determine likelihood promoting with continued use these antibiotics. Minimum inhibitory concentration (MIC) values against were determined each antimicrobial agent based on microdilution broth agar dilution methods (bacterial numbers ranged from 105 colony-forming units (CFU)/mL 109 CFU/mL). The minimal inhibiting colony formation by 99% (MIC99) prevention (MPC) method three inoculum sizes. Antimicrobial killing was MIC99 MPC all five agents. MIC 0.001 0.25 μg/mL method, 0.008 1.0 method. 0.0016 10.24 μg/mL. MPC/MIC99 ordered tylosin > doxycycline danofloxacin tiamulin valnemulin. achieved better bactericidal action than MIC99. Based pharmacodynamic analyses, are more likely select resistant mutants