Contribution of Enhanced Efflux to Reduced Susceptibility of Salmonella enterica Serovar Choleraesuis to Fluoroquinolone and Other Antimicrobials

Journal of Veterinary Medical Science

Hidetaka NAGAI²  Tetsuo ASAI²  Yoshimi YAMAMOTO¹  Mariko UCHIYAMA²  Masaru USUI²  Kotaro BABA² 

[1] Department of Veterinary Sciences, Faculty of Agriculture, Yamaguchi University;National Veterinary Assay Laboratory, Ministry of Agriculture, Forestry and Fisheries

关键词: antimicrobial resistance;    efflux pump;    fluoroquinolone resistance;    laboratory-derived mutant;    S. Choleraesuis;   

DOI  :  10.1292/jvms.10-0309

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

References(25)Cited-By(2)We examined antimicrobial susceptibility and efflux systems in laboratory-derived mutants of Salmonella enterica serovar Choleraesuis selected by culture on fluoroquinolone-containing plates. The mutants exhibited decreased susceptibilities to quinolones and several other antimicrobials. Mutations in the gyrA gene were not always found in the mutants. Accumulation assays revealed that intracellular enrofloxacin concentrations were significantly lower in the mutants compared with parent isolates. Increased expression of acrB mRNA can explain the decreased susceptibilities to several antimicrobials but not in the case of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Decreased susceptibility to CCCP may result from the increased expression of emrA mRNA. These results suggest that the enhancement of multiple efflux pumps is responsible for decreased susceptibilities to several antimicrobials in the laboratory-derived mutants.

【 授权许可】

Unknown