Damage of Escherichia coli membrane by bactericidal agent polyhexamethylene guanidine hydrochloride: micrographic evidences

Abstract

Aims: The purpose of this study was to provide micrographic evidences for the damaged membrane structure and intracellular structure change of Escherichia coli strain 8099, induced by polyhexamethylene guanidine hydrochloride (PHMG). Methods and Results: The bactericidal effect of PHMG on E. coli was investigated based on β‐galactosidase activity assay, fluorescein‐5‐isothiocyanate confocal laser scanning microscopy, field emission scanning electron microscopy and transmission electron microscopy. The results revealed that a low dose (13 μg ml−1) of PHMG slightly damaged the outer membrane structure of the treated bacteria and increased the permeability of the cytoplasmic membrane, while no significant damage was observed to the morphological structure of the cells. A high dose (23 μg ml−1) of PHMG collapsed the outer membrane structure, led to the formation of a local membrane pore across the membrane and badly damaged the internal structure of the cells. Subsequently, intracellular components were leaked followed by cell inactivation. Conclusions: Dose‐dependent membrane disruption was the main bactericidal mechanism of PHMG. The formation of the local membrane pores was probable after exposure to a high dose (23 μg ml−1) of PHMG. Micrographic evidences were provided about the damaged membrane structure and intracellular structure change of E. coli. Significance and Impact of the Study: The presented information helps understand the bactericidal mechanism of PHMG by membrane damage.

Antimicrobial Activity of Polyhexamethylene Guanidine Derivatives Introduced into Polycaprolactone

“…Our research results showed that S. aureus formed less biofilm than E. coli. Research by Zhou et al [12] indicates that low PHMG concentrations only damaged the external structures of bacterial cell membrane. Das et al [13] determined the ability of E. coli and S. aureus to form biofilm on polymers with incorporated polyhexamethylene biguanide in the presence of acetic acid.…”

“…Most AMMs (anti-microbial macromolecules) including PHMG have the charge and hydrophobicity moieties as anti-microbial peptides [22], and many researchers speculate that AMMs act by disruptive interaction on the lipid interface membrane as anti-microbial peptides, but there was a lack of experimental evidences on membrane disruption and their biological mechanism [22,23]. According to Zhou et al [12] and Linyan et al [24] the biocidal activity of PHMG may be related to its ability to damage the cell membrane. Most probably, PHMG first damages the outer membrane, and then higher concentrations result in damage to of the cell wall and cytoplasmic membrane [12].…”

“…According to Zhou et al [12] and Linyan et al [24] the biocidal activity of PHMG may be related to its ability to damage the cell membrane. Most probably, PHMG first damages the outer membrane, and then higher concentrations result in damage to of the cell wall and cytoplasmic membrane [12]. Walczak et al [25] showed that PLA with PHMG derivatives did not inhibit the activity of extracellular hydrolytic enzymes, which means that the introduction of PHMG derivatives into PLA will not reduce its enzymatic biodegradation significantly.…”

In Vitro Assessment of the Toxic Effects of an AKWATON based-disinfectant on Human Tissues

“…AKWATON is a new colorless, odorless, non-corrosive antimicrobial product with excellent microbicidal power. Its antimicrobial activities have been widely documented [19,[25][26][27].…”

Interactions of biocidal guanidine hydrochloride polymer analogs with model membranes: a comparative biophysical study

“…We have recently reported that the cytoplasmic membrane disruption of bacteria cells induced by PHMG-membrane interactions is the main antibacterial mechanism by micrographic observations of Escherichia coli cells exposed to PHMG [9,16]. However, a detailed characterization of interactions between the guanidine hydrochloride polymer molecule and the phospholipid membrane has not yet been performed.…”