mfsQ encoding an MFS efflux pump mediates adaptive protection of Stenotrophomonas maltophilia against benzalkonium chloride

Abstract

The persistence of Stenotrophomonas maltophilia, especially in hospital environments where disinfectants are used intensively, is one of the important factors that allow this opportunistic pathogen to establish nosocomial infections. In the present study, we illustrated that S. maltophilia possesses adaptive resistance to the disinfectant benzalkonium chloride (BAC). This BAC adaptation was abolished in the ΔmfsQ mutant, in which a gene encoding an efflux transporter belonging to the major facilitator superfamily (MFS) was deleted. The ΔmfsQ mutant also showed increased susceptibility to BAC and chlorhexidine gluconate relative to a parental wild type. The expression of mfsQ increased upon exposure to quaternary ammonium compounds, including BAC. Thus, the results of this study suggest that mfsQ plays a role in both adaptive and non-adaptive protection of S. maltophilia from the toxicity of the disinfectant BAC.

Contribution of Stenotrophomonas maltophilia MfsC transporter to protection against diamide and the regulation of its expression by the diamide responsive repressor DitR

“…Total RNA was extracted from exponential-phase cultures of S . maltophilia wild-type K279a grown under uninduced conditions and induced with sublethal concentrations of diamide, H 2 O 2 , cumene hydroperoxide, electrophile NEM, redox cycling drugs (menadione, plumbagin, paraquat, and phenazine), and biocide QACs (acriflavine and benzalkonium chloride) [ 10 , 25 ]. The 16S ribosomal RNA was used as the normalizing gene.…”

“…The contribution of MFS efflux pumps to the resistance of S. maltophilia against herbicide paraquat, antibiotics, and disinfectant quaternary ammonium compounds (QACs) has been previously reported [9,10,25]. The genome of S. maltophilia contains many putative genes encoding MFS with an unknown function [3,26].…”

“…The expression levels of mfsC in response to stresses, including oxidative stress and disinfectants, were determined using RT-PCR. Total RNA was extracted from exponential-phase cultures of S. maltophilia wild-type K279a grown under uninduced conditions and induced with sublethal concentrations of diamide, H 2 O 2 , cumene hydroperoxide, electrophile NEM, redox cycling drugs (menadione, plumbagin, paraquat, and phenazine), and biocide QACs (acriflavine and benzalkonium chloride) [10,25]…”

Efflux-mediated tolerance to cationic biocides, a cause for concern?

“…Bacterial efflux is a common component of increased tolerance to BAC in a number of bacterial species, including Listeria monocytogenes [60], P. aeruginosa [61], Stenotrophomonas maltophilia [62] and Escherichia coli [63]. Studies have shown that increased tolerance to BAC in L.…”

New insight into the production improvement and resource generation of chaetoglobosin A in Chaetomium globosum

“…Major facilitator superfamily (MFS) represents the largest group of secondary active transporters that are ubiquitously present across all living organisms, and mediates antiportation, uniportation and symportation of sugars, peptides, vitamins, deleterious substances, inorganic ions, chromophores, neurotransmitters and many other small molecules (Chen et al, 2008 ; Chittrakanwong et al, 2021 ; Lee et al, 2021 , 2016 ; Liu et al, 2019 ; Yen et al, 2010 ). Owing to their characteristics such as low substrate specificity and high drugs sensitivity, MFS transporters exert an important effect on various physiological processes and are progressively being identified as potential drug targets.…”