The response of Escherichia coli to exposure to the biocide polyhexamethylene biguanide

Abstract

The global response of Escherichia coli to the broad-spectrum biocide polyhexamethylene biguanide (PHMB) was investigated using transcriptional profiling. The transcriptional analyses were validated by direct determination of the PHMB-tolerance phenotypes of derivatives of E. coli MG1655 carrying either insertionally inactivated genes and/or plasmids expressing the cognate open reading frames from a heterologous promoter in the corresponding chromosomally inactivated strains. The results showed that a wide range of genes was altered in transcriptional activity and that all of the corresponding knockout strains subsequently challenged with biocide were altered in tolerance. Of particular interest was the induction of the rhs genes and the implication of enzymes involved in the repair/binding of nucleic acids in the generation of tolerance, suggesting a novel dimension in the mechanism of action of PHMB based on its interaction with nucleic acids.

Importance of Porins for Biocide Efficacy against Mycobacterium smegmatis

“…Polyhexamethylene biguanide (PHMB) and octenidine are lipophilic biocides. PHMB is a fast-acting, broad-spectrum biocide effective at low concentrations against bacteria and viruses and is used as a preservative in cosmetics, personal care products, fabric softeners, contact lens solutions, and hand washes and as a sanitizer in swimming pools and hot tubs due to its stability in sunlight and its resistance against heat and pH fluctuations (1). Octenidine dihydrochloride is a cationic lipophilic biocide of high molecular weight ( Fig.…”

Adverse health effects of humidifier disinfectants in Korea: lung toxicity of polyhexamethylene guanidine phosphate

“…Guanidine-based antimicrobials were thus believed to have low toxicity to humans (Ikeda et al, 1983(Ikeda et al, , 1984. However, recent accounts have reported PHMB penetrating mammalian cells and interacting with chromosomes, raising concerns about health hazards from guanidine-based antimicrobials (Allen et al, 2004(Allen et al, , 2006Chindera et al, 2016;Firdessa et al, 2015).…”

rhs Genes Are Potential Markers for Multilocus Sequence Typing of Escherichia coli O157:H7 Strains

“…The function(s) of rhs genes is still unknown; however, several studies have shed light on this puzzle. The mature proteins are predicted to be extracellular (18), and phenotypes reported include promotion of the intestinal colonization of E. coli in calves (40), the biogenesis of group 2 capsules (31), and increasing the resistance of E. coli to the biocide polyhexamethylene biguanide (3). Taking all these together, we hypothesize that Rhs proteins promote survival of E. coli during intestinal transit in some undefined manner and that their extracellular nature results in a strong positive se-lective pressure from the host's immune system.…”