title: In Vitro Development of Ciprofloxacin Resistance of Salmonella enterica Serovars Typhimurium, Enteritidis, and Indiana Isolates from Food Animals.
abstract: Difference in the development of resistance may be associated with the epidemiological spread and drug resistance of different Salmonella enterica serovar strains. In the present study, three susceptible S. enterica serovars, Typhimurium (ST), Enteritidis (SE), and Indiana (SI) strains, were subjected to stepwise selection with increasing ciprofloxacin concentrations. The results indicated that the mutation frequencies of the SI group were 101-104higher and developed resistance to ciprofloxacin more rapidly compared with the ST and SE groups. Ciprofloxacin accumulation in the SI strain was also higher than the other two strains in the presence of an efflux pump inhibitor. The development of ciprofloxacin resistance was quite different among the three serovar strains. In SI, increasing AcrAB-TolC efflux pump expression and single or double mutations in gyrA with or without a single parC mutation (T57S) were found in the development of ciprofloxacin resistance. In SE, an increase in the AcrAB-TolC efflux pump regulatory gene ramA gradually decreased as resistant bacteria developed; then resistance resulted from gyrA D87G and gyrB E466D mutations and/or in other active efflux pumps besides AcrAB-TolC. For ST, ramA expression increased rapidly along with gyrA D87 N and/or gyrB S464F mutations. In conclusion, persistent use of ciprofloxacin may aggravate the resistance of different S. enterica serovars and prudent use of the fluoroquinolones is needed. The quicker resistance and higher mutation frequency of the SI isolates present a potential public health threat.
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University (SCAU) , Guangzhou, China .
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Zhang
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University (SCAU) , Guangzhou, China .
authors.forename: Chuan-Zhen
authors.initials: CZ
authors.lastname: Zhang
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University (SCAU) , Guangzhou, China .
authors.forename: Zhi-Jie
authors.initials: ZJ
authors.lastname: Liu
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University (SCAU) , Guangzhou, China .
authors.forename: Xi-Xi
authors.initials: XX
authors.lastname: Gu
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University (SCAU) , Guangzhou, China .
authors.forename: Wan
authors.initials: W
authors.lastname: Li
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University (SCAU) , Guangzhou, China .
authors.forename: Ling
authors.initials: L
authors.lastname: Yang
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University (SCAU) , Guangzhou, China .
authors.forename: Ya-Hong
authors.initials: YH
authors.lastname: Liu
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University (SCAU) , Guangzhou, China .
authors.forename: Zhen-Ling
authors.initials: ZL
authors.lastname: Zeng
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University (SCAU) , Guangzhou, China .
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Jiang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D002939:Ciprofloxacin / Q000494:pharmacology*; D027081:DNA Gyrase / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics*; D024841:Fluoroquinolones / Q000494:pharmacology; D005502:Food; D008826:Microbial Sensitivity Tests / Q000379:methods; D009154:Mutation / Q000187:drug effects / Q000235:genetics; D019779:Salmonella enterica / Q000187:drug effects* / Q000235:genetics*; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000235:genetics*; D065288:Serogroup
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D024841:Fluoroquinolones; D002939:Ciprofloxacin; D027081:DNA Gyrase
keywords: S. Enteritidis; S. Indiana; S. Typhimurium; ciprofloxacin resistance; in vitro