Two different mechanisms are involved in the extremely high-level benzalkonium chloride resistance of a Pseudomonas fluorescens strain.
A Pseudomonas fluorescens strain, PFRB, which we previously isolated as a contaminant in a batch of benzalkonium chloride (BAC) stock solution, exhibits high-level resistance, not only to BAC, but also to other cationic surfactants belonging to disinfectants classified as quaternary ammonium compounds (QACs). In this study, we analyzed the resistance mechanism of the strain to BAC and other disinfectants. We obtained results suggesting that two different mechanisms, reduced adsorption of BAC to the cell surface and an energy-dependent mechanism which is most probably an efflux system, were implicated in the high-level resistance to BAC. Reduced adsorption of BAC is likely due to the decreased negative cell surface charge of the strain. The putative efflux system seems to be unique in that it excretes only a certain range of cationic membrane-acting disinfectants belonging to QACs.
Nagai
Katsuhiro
K
Department of Pharmacy, Shinshu University Hospital, Matsumoto, Nagano 390-8621, Japan.
Murata
Takahiro
T
Ohta
Shin
S
Zenda
Hiroshi
H
Ohnishi
Makoto
M
Hayashi
Tetsuya
T
D000327:Adsorption; D001548:Benzalkonium Compounds / Q000494:pharmacology*; D002463:Cell Membrane Permeability; D003902:Detergents / Q000494:pharmacology; D004202:Disinfectants / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008826:Microbial Sensitivity Tests; D011551:Pseudomonas fluorescens / Q000187:drug effects*; D013499:Surface Properties; D013501:Surface-Active Agents / Q000494:pharmacology
D001548:Benzalkonium Compounds; D003902:Detergents; D004202:Disinfectants; D013501:Surface-Active Agents