Plasmid-mediated quinolone resistance: Two decades on

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Plasmid-mediated quinolone resistance (PMQR) has been recognized for two decades.
• PMQR encompasses three primary mechanisms: target protection (Qnr proteins), active efflux (QepA, OqxAB), and drug modification (AAC(6')-Ib-cr).
• PMQR genes are frequently linked to mobile genetic elements and integrons, facilitating their dissemination.

Purpose of the Study:

• To review the mechanisms and spread of plasmid-mediated quinolone resistance.
• To highlight the clinical and environmental significance of PMQR.
• To discuss the implications of PMQR for antimicrobial therapy.

Main Methods:

• Literature review of studies on PMQR mechanisms.
• Analysis of gene association with mobile elements and integrons.
• Examination of global distribution in clinical and environmental isolates.

Main Results:

• Qnr proteins, QepA/OqxAB efflux pumps, and AAC(6')-Ib-cr are the key PMQR mechanisms.
• PMQR genes are commonly found on plasmids and within integrons.
• PMQR is widespread globally in various microbial isolates.
• Low-level resistance from PMQR can synergize with chromosomal resistance to achieve clinical significance.

Conclusions:

• PMQR mechanisms contribute to the global spread of quinolone resistance.
• The combination of PMQR with other resistance factors poses a significant threat to effective antimicrobial treatment.
• Continued surveillance and understanding of PMQR are crucial for public health.