摘要:Stenotrophomonas maltophilia exhibits wide spectrum of fluoroquinolone resistance using different mechanisms as multidrug efflux pumps and Sm
qnr alleles. Here, the role of
smeDEF,
smeVWX efflux genes and contribution of Sm
qnr alleles in the development of fluoroquinolone resistance was assessed. Ciprofloxacin, levofloxacin and moxifloxacin resistance were found in 10.9%, 3.5%, and 1.6% of isolates, respectively. More than four-fold differences in ciprofloxacin MICs were detected in the presence of reserpine and
smeD, F, V expression was significantly associated with ciprofloxacin resistance (p = 0.017 for
smeD, 0.003 for
smeF, and 0.001 for
smeV). Sm
qnr gene was found in 52% of the ciprofloxacin-resistant isolates and Sm
qnr8 was the most common allele detected. Fluoroquinolone resistance in
S. maltophilia clinical isolates was significantly associated with active efflux pumps. There was no correlation between the Sm
qnr alleles and ciprofloxacin resistance; however, contribution of the Sm
qnr genes in low-level levofloxacin resistance was revealed.