title: Determination of the Mutant Selection Window and Evaluation of the Killing of Mycoplasma gallisepticum by Danofloxacin, Doxycycline, Tilmicosin, Tylvalosin and Valnemulin.
abstract: Mycoplasma gallisepticum is a common etiological cause of a chronic respiratory disease in chickens; its increasing antimicrobial resistance compromises the use of tetracyclines, macrolides and quinolones in the farm environment. Mutant selection window (MSW) determination was used to investigate the propensity for future resistance induction by danofloxacin, doxycycline, tilmicosin, tylvalosin and valnemulin. Killing of M. gallisepticum strain S6 by these antimicrobials was also studied by incubating M. gallisepticum into medium containing the compounds at the minimal concentration that inhibits colony formation by 99% (MIC99) and the mutant prevention concentration (MPC). Based on the morphology and colony numbers of M. gallisepticum on agar plates, the four kinds of sera in the order of the applicability for culturing M. gallisepticum were swine serum > horse serum > bovine serum > mixed serum. The MPC/MIC99 values for each agent were as follows: danofloxacin > tilmicosin > tylvalosin > doxycycline > valnemulin. MPC generated more rapid and greater magnitude killing than MIC99 against M. gallisepticum. Under exposure of 105-109 CFU/mL at MPC drug levels, valnemulin had the slowest rate of reduction in viable organisms and danofloxacin had the highest rate of reduction.
authors.affiliation: Guangdong Key Laboratory for Veterinary Drug Development and Safety evaluation, South China Agricultural University, Guangzhou, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Guangdong Key Laboratory for Veterinary Drug Development and Safety evaluation, South China Agricultural University, Guangzhou, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Ye
authors.affiliation: Guangdong Key Laboratory for Veterinary Drug Development and Safety evaluation, South China Agricultural University, Guangzhou, China.
authors.forename: Yuzhi
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Guangdong Key Laboratory for Veterinary Drug Development and Safety evaluation, South China Agricultural University, Guangzhou, China.
authors.forename: Zilong
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Guangdong Key Laboratory for Veterinary Drug Development and Safety evaluation, South China Agricultural University, Guangzhou, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Gu
authors.affiliation: Technical Center of Zhuhai Entry-Exit Inspection and Quarantine Bureau, Zhuhai, China.
authors.forename: Qinren
authors.initials: Q
authors.lastname: Cai
authors.affiliation: Guangdong Key Laboratory for Veterinary Drug Development and Safety evaluation, South China Agricultural University, Guangzhou, China.
authors.forename: Xiangguang
authors.initials: X
authors.lastname: Shen
authors.affiliation: Guangdong Key Laboratory for Veterinary Drug Development and Safety evaluation, South China Agricultural University, Guangzhou, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Guangdong Key Laboratory for Veterinary Drug Development and Safety evaluation, South China Agricultural University, Guangzhou, China.
authors.forename: Huanzhong
authors.initials: H
authors.lastname: Ding
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004224:Diterpenes / Q000494:pharmacology; D004318:Doxycycline / Q000494:pharmacology*; D024841:Fluoroquinolones / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D045686:Mycoplasma gallisepticum / Q000187:drug effects*; D015645:Tylosin / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D004224:Diterpenes; D024841:Fluoroquinolones; C068581:danofloxacin; C117845:valnemulin; C545430:tylvalosin; D004318:Doxycycline; C052319:tilmicosin; D015645:Tylosin