Mechanism of resistance to benzalkonium chloride by Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa to benzalkonium chloride (BC) were studied. The effluence of cell components was observed in susceptible P. aeruginosa by electron microscopy, but resistant P. aeruginosa seemed to be undamaged. No marked changes in cell surface potential between Escherichia coli NIHJC-2 and a spheroplast strain were found. The contents of phospholipids (PL) and fatty and neutral lipids (FNL) in the cell walls of resistant P. aeruginosa were higher than those in the cell walls of susceptible P. aeruginosa. The amounts of BC adsorbed to PL and FNL of cell walls of BC-resistant P. aeruginosa were lower than those for BC-susceptible P. aeruginosa. Fifteen species of cellular fatty acids were identified by capillary gas chromatography and gas chromatography-mass spectrometry. The ability of BC to permeate the cell wall was reduced because of the increase in cellular fatty acids. These results suggested that the resistance of P. aeruginosa to BC is mainly a result of increases in the contents of PL and FNL. In resistant P. aeruginosa, the decrease in the amount of BC adsorbed is likely to be the result of increases in the contents of PL and FNL. There are many reports on the mechanisms of bacterial resistance to antibiotics (5

Menadione‐Catalyzed O2– Production by Escherichia coli Cells: Application of Rapid Chemiluminescent Assay to Antimicrobial Susceptibility Testing

“…The decrease in LC after the transient peak of LC suggests inactivation of NAD(P)H:menadione reductase by the leakage of intracellular constituents or the removal of O 2 -by the leakage of SOD. Benzalkonium chloride may also induce a transient increase in LC by behaving like polymixin B, because this surface-active agent is known to induce changes in membrane fluidity, and in osmosis and cell lysis by interacting with phospholipids (17). On the other hand, CCCP showed rapid inhibitory effects on menadione-catalyzed LC.…”

The relationships and susceptibilities of some industrial, laboratory and clinical isolates of Pseudomonas aeruginosa to some antibiotics and biocides

“…Mutants with LPS deletions in the outer membrane have been shown to be more sensitive to QACs than the wild-type: shielding of the phospholipids through the interaction of the LPS with QACs, reducing the ability of these compounds to permeate through, and act on, the cytoplasmic membrane. Sakagami et al (1989) found an increase in the content of phospholipids and fatty and neutral lipids (FNL) in cell walls of BK-resistant Ps. aeruginosa.…”

Antimicrobial cationic surfactant, cetyltrimethylammonium bromide, induces superoxide stress in Escherichia coli cells

“…Scharff and Maupin (1960) demonstrated that benzalkonium chloride disrupted or disturbed cell membrane in yeast cells. Sakagami et al (1989) observed leakage of intracellular K + and other cell components after treatment with an antimicrobial surfactant. Other researchers have also observed cell autolysis (Cho et al 1990;Tsuchido et al 1990;Ioannou et al 2007) and inhibition of respiration (Ishikawa et al 2002b).…”