Stenotrophomonas maltophilia contains a novel chromosomally-encoded qnr gene named Smqnr that contributes to low intrinsic resistance to quinolone. We described Smqnr in 13 clinical isolates of S. maltophilia from two Brazilian hospitals, over a 2-year period. The strains were identified by API 20 NE (bioMérieux, France). Susceptibility by microdilution method to trimetroprim/sulfamethoxazole, ...

OBJECTIVES To characterize the role of SmqnrR in the expression of Smqnr and SmtcrA, and the role of SmtcrA in drug resistance in Stenotrophomonas maltophilia. METHODS SmqnrR, a DeoR-type regulator gene, is situated between a quinolone resistance gene (Smqnr) and a putative major facilitator superfamily transmembrane transporter gene (SmtcrA). To assess the regulatory role of SmQnrR in the ex...

Stenotrophomonas maltophilia is an important pathogen in healthcare-associated infections. S. maltophilia may contain Smqnr, a quinolone resistance gene encoding the pentapeptide repeat protein, which confers low-level quinolone resistance upon expression in a heterologous host. We investigated the prevalence of Smqnr and plasmid-mediated quinolone resistance (PMQR) determinants in S. maltophil...

BACKGROUND Recent analysis of Stenotrophomonas maltophilia has identified a novel family of resistance genes (Smqnr) encoding pentapeptide repeat proteins, which confer low-level resistance to quinolones. This study describes further novel variants present in clinical isolates of S. maltophilia and investigates their effect on resistance to a number of quinolones in an Escherichia coli host. ...

We have determined that the mutational inactivation of the SmeDEF efflux pump and the SmQnr quinolone resistance protein widens the mutant selection windows for ofloxacin and ciprofloxacin of Stenotrophomonas maltophilia by reducing their MICs. Resistant mutants arising from a strain lacking SmeDEF and SmQnr presented levels of susceptibility similar to those of the wild-type strain. This indic...

OBJECTIVE The purpose of this study was to investigate the clinical distribution and genotyping of Stenotrophomonas maltophilia, its resistance to antimicrobial agents, and the possible mechanisms of this drug resistance. METHODS S. maltophilia isolates were collected from clinical specimens in a university hospital in Northwestern China during the period between 2010 and 2012, and were ident...

Objective(s): Stenotrophomonas maltophilia has emerged as an important opportunistic nosocomial pathogen due to its intrinsic and acquired resistance to a wide range of antimicrobial agents. The present study aimed to investigate the occurrence of antibiotic resistance and resistance mechanisms among clinical isolates of S. maltophilia from Iranian patients.<...

Environmental bacteria harbor a plethora of genes that, upon their horizontal transfer to new hosts, may confer resistance to antibiotics, although the number of such determinants actually acquired by pathogenic bacteria is very low. The founder effect, fitness costs and ecological connectivity all influence the chances of resistance transfer being successful. We examined the importance of thes...