Gemini Cationic Amphiphiles Control Biofilm Formation by Bacterial Vaginosis Pathogens

Abstract

Antibiotic resistance and recurrence of bacterial vaginosis (BV), a polymicrobial infection, justify the need for novel antimicrobials to counteract microbial resistance to conventional antibiotics. Previously, two series of cationic amphiphiles (CAms) which self-assemble into supramolecular nanostructures with membrane-lytic properties were designed with hydrophilic head groups and nonpolar domains. The combination of CAms and commonly prescribed antibiotics is suggested as a promising strategy for targeting microorganisms that are resistant to conventional antibiotics. Activities of the CAms against ATCC 14018, a representative BV pathogen, ranged from 1.1 to 24.4 μM. Interestingly, the tested healthy species, especially ATCC 39268, were significantly more tolerant of CAms than the selected pathogens. In addition, CAms prevented biofilm formation at concentrations which did not influence the normal growth ability of ATCC 14018. Furthermore, the biofilm minimum bactericidal concentration (MBC-Bs) of CAms against ATCC 14018 ranged from 58.8 to 425.6 μM, while much higher concentrations (≥850 μM) were required to produce ≥3-log reductions in the number of biofilm-associated lactobacilli. The conventional antibiotic metronidazole synergized strongly with all tested CAms against planktonic cells and biofilms of ATCC 14018. The synergism between CAms and the tested conventional antibiotic may be considered a new, effective, and beneficial method of controlling biofilm-associated bacterial vaginosis.

The Female Vaginal Microbiome in Health and Bacterial Vaginosis

“…Endolysin (PM-477) can selectively and effectively eliminate Gardnerella in native polymicrobial biofilm and in cultures of isolated strains (Landlinger et al, 2021). Other strategies involving the utilization of boric acid (Reichman et al, 2009), octenidine (Swidsinski et al, 2015), cationic amphiphiles (Algburi et al, 2017;Weeks et al, 2019), and amphoteric tenside (WO3191) also reportedly have a positive effect on BV-associated biofilms (Gottschick et al, 2017). Microbial-based therapeutics have recently attracted an increasing amount of interest owing to the beneficial effects to the host health.…”

Extrapulmonary Surfactant Therapy: Review of Available Data and Research/Development Issues

“…Chemically synthetized ionic surfactants have been produced and tested to treat bacterial vaginosis and/or control the associated biofilm 82,83 . Surfactants have also been tested as spermicides and as prophylactic agents against various sexually transmitted infections (STIs).…”

“…Chemically synthetized ionic surfactants have been produced and tested to treat bacterial vaginosis and/or control the associated biofilm. 82,83 Surfactants have also been tested as spermicides and as prophylactic agents against various sexually transmitted infections (STIs). Surfactants seem to have a significant bactericidal activity against various bacteria responsible for STIs, whereas their fungicidal activity against Candida albicans is limited, and they are not able to inhibit adenovirus and lentivirus infections of epithelial cells.…”

Current Concepts of <i>Gardnerella vaginalis</i> Biofilm: Significance in Bacterial Vaginosis

“…These complexes are able to decrease development of GV biofilms specifically, with morphological and structural changes in these biofilms demonstrated by scanning electron microscopy. Further, amphiphiles furnished activity against biofilm without harming Lactobacillus [41]. Thus, this treatment is theoretically able to prevent biofilm formation without disrupting Lactobacillus strains.…”