Assessment of the mode of action of polyhexamethylene biguanide against Listeria innocua by Fourier transformed infrared spectroscopy and fluorescence anisotropy analysis

Abstract

Polyhexamethylene biguanide (PHMB) is a cationic biocide. The antibacterial mode of action of PHMB (at concentrations not exceeding its minimal inhibitory concentration) upon Listeria innocua LRGIA 01 was investigated by Fourier transformed infrared spectroscopy and fluorescence anisotropy analysis. Fourier transformed infrared spectra of bacteria treated with or without PHMB presented some differences in the lipids region: the CH(2)/CH(3) (2924 cm(-1)/2960 cm(-1)) band areas ratio significantly increased in the presence of PHMB. Since this ratio generally reflects membrane phospholipids and membrane microenvironment of the cells, these results suggest that PHMB molecules interact with membrane phospholipids and, thus, affect membrane fluidity and conformation. To assess the hypothesis of PHMB interaction with L. innocua membrane phospholipids and to clarify the PHMB mode of action, we performed fluorescence anisotropy experiments. Two probes, 1,6-diphenyl-1,3,5-hexatriene (DPH) and its derivative 1-[4-(trimethyl-amino)-phenyl]-6-phenylhexa-1,3,5-triene (TMA-DPH), were used. DPH and TMA-DPH incorporate inside and at the surface of the cytoplasmic membrane, respectively. When PHMB was added, an increase of TMA-DPH fluorescence anisotropy was observed, but no changes of DPH fluorescence anisotropy occurred. These results are consistent with the hypothesis that PHMB molecules perturb L. innocua LRGIA 01 cytoplasmic membrane by interacting with the first layer of the membrane lipid bilayer.

Comparing two polymeric biguanides: chemical distinction, antiseptic efficacy and cytotoxicity of polyaminopropyl biguanide and polyhexamethylene biguanide

“…Because of these attributes PHMB displays increased membrane permeability, facilitating its interaction with bacterial membranes compared to PAPB and its transfer into the cell, where it disturbs the metabolism of the micro-organisms [reviewed by Hubner & Kramer (2010) and Kaehn (2010)]. Recent research further supports the interaction with bacterial membranes as the mode of action for PHMB, stating that it disturbs the first layer of the membrane lipid bilayer (Chadeau et al, 2012) by electrostatic as well as hydrophobic interactions and dehydration (Souza et al, 2015). However, a new study also strengthened the hypothesis of additional mechanisms of the bactericidal effect of PHMB based on the interaction of the infiltrated substance with bacterial chromosomes (Chindera et al, 2016).…”

Effect of a wound cleansing solution on wound bed preparation and inflammation in chronic wounds: a single-blind RCT

“…Thus, it is difficult to perform intense debridement at patients' home, where clinicians should provide the best quality care without compromising patients' safety. Based on published evidence 9,10,12,17,20,[22][23][24][25] we identified PP solution as a good candidate to replace NS in order to accelerate wound autolytic debridement.…”

“…The combination of 0.1% polihexanide and 0.1% betaine offers a lower surface tension than the individual substances. 23,24 A number of authors have investigated the clinical efficacy of PP solution in the management of chronic wounds. Moeller et al published a retrospective assessment of the management of chronic wounds using PP solution in 953 patients.…”

Aqueous humor pharmacokinetics of Benzalkonium chloride free bimatoprost formulated in tight junction modulation technology compared to Benzalkonium chloride preserved bimatoprost 0.01% ophthalmic solution in rabbit eyes

“…TJM technology improves corneal retention and permeation and are made up of two molecule, namely, 1) TJM-1, a negatively charged surfactant, can solubilize claudin and phosphorylate proteins in the tight junctions, 15,16 2) TJM-2, a positively charged polymeric molecule, which increases the fluidity of the membrane and delays claudin remodelling, 17 ultimately leading to better permeation of the drug. 18 In the GFR technology, there are two polymers, which increases the mean residence time and provides lubrication as well. Therefore, the two complementary technologies i.e.…”