The Efflux Pump SmeDEF Contributes to Trimethoprim-Sulfamethoxazole Resistance in Stenotrophomonas maltophilia

Abstract

ABSTRACTTrimethoprim-sulfamethoxazole (co-trimoxazole) is one of the antimicrobials of choice for the treatment ofStenotrophomonas maltophiliainfections. The analysis of mutants either lacking or overexpressing the efflux pump SmeDEF shows that this efflux pump contributes to intrinsic and acquired co-trimoxazole resistance inS. maltophilia. Since SmeDEF can extrude a variety of antibiotics, selection with such antimicrobials, including quinolones, might also select forS. maltophiliaco-trimoxazole resistance.