Osong Public Health Res Perspect.  2011 Dec;2(3):216-217. 10.1016/j.phrp.2011.11.049.

A Contribution of MdfA to Resistance to Fluoroquinolones in Shigella flexneri

• Kim JY
• Jeon SM
• Kim H
• Park MS
• Kim SH

• KMID: 2517990
• DOI: http://doi.org/10.1016/j.phrp.2011.11.049

Abstract

In this study, we measured the drug resistance conferred by mdfA mutations in two Shigella flexneri strains. A mutant in mdfA genes was constructed by polymerase chain reaction–based, one-step inactivation of chromosomal genes. The antimicrobial susceptibility of parent and mutant strains to fluoroquinolones was determined by minimal inhibitory concentration (MICs). The △mdfA mutants were somewhat more susceptible to fluoroquinolones than the parent strains. The low level changes in MICs of the △mdfA mutants suggest that mdfA contributed the fluoroquinolone resistance in S flexneri. This finding found that the increased expression level of an MdfA efflux pump mediated fluoroquinolone resistance, but it is not likely a major effecter of higher resistance levels.

Keyword

efflux pump; fluoroquinolones resistance; MdfA