Rapid detection of Fluoroquinolone-Resistant Escherichia coli using mass spectrometry

摘要

A total panel of 38 strains resistant to fluoroquinolones was injected with the multiplexed SRM method and 3 susceptible strains were used as controls. Twenty-eight strains were found to have a mutation within the QRDR, which was confirmed by PCR and sequencing, resulting in 100% agreement. Ten strains harboring plasmid-mediated resistance were injected. Eight were positive for one or more Qnr, QnrA, QnrB, QnrC, and QnrD, AAC(6')-1b-cr, or Oqx. Only uncommon QepA and QnrS were not readily detected in 2 strains. In clinics, most fluoroquinolone resistant E. coli harbor at least one mutation within the QRDR. Multiplexing detection of both chromosomal and plasmid-encoded mechanisms, the reported method was able to detect in 1h resistance to fluoroquinolone for the vast majority of strains.