A quaternary ammonium silane antimicrobial triggers bacterial membrane and biofilm destruction

Abstract

To study the antimicrobial effects of quaternary ammonium silane (QAS) exposure on Streptococcus mutans and Lactobacillus acidophilus bacterial biofilms at different concentrations. Streptococcus mutans and Lactobacillus acidophilus biofilms were cultured on dentine disks, and incubated for bacterial adhesion for 3-days. Disks were treated with disinfectant (experimental QAS or control) and returned to culture for four days. Small-molecule drug discovery-suite was used to analyze QAS/Sortase-A active site. Cleavage of a synthetic fluorescent peptide substrate, was used to analyze inhibition of Sortase-A. Raman spectroscopy was performed and biofilms stained for confocal laser scanning microscopy (CLSM). Dentine disks that contained treated dual-species biofilms were examined using scanning electron microscopy (SEM). Analysis of DAPI within biofilms was performed using CLSM. Fatty acids in bacterial membranes were assessed with succinic-dehydrogenase assay along with time-kill assay. Sortase-A protein underwent conformational change due to QAS molecule during simulation, showing fluctuating alpha and beta strands. Spectroscopy revealed low carbohydrate intensities in 1% and 2% QAS. SEM images demonstrated absence of bacterial colonies after treatment. DAPI staining decreased with 1% QAS (p < 0.05). Fatty acid compositions of dual specie biofilm increased in both 1% and 2% QAS specimens (p < 0.05). Quaternary ammonium silane demonstrated to be a potent antibacterial cavity disinfectant and a plaque inhibitor and can be of potential significance in eliminating caries-forming bacteria.

Molecular Dynamic Simulation Search for Possible Amphiphilic Drug Discovery for Covid-19

“…Quaternary amphiphilic compounds (QACs) have both surfactant properties and broad-spectrum antimicrobial activity and hence are widely used as antibacterial agents. Although the exact mechanism behind the antimicrobial properties of QACs is not fully understood, it is well accepted that QACs can solubilize phospholipid bilayers inside membranes, leading to progressive cell lysis [24]. We can corroborate our assumption on the mode of action of the amphiphilic compounds on the viral envelope and its subsequent survival inside the host cell [25].…”

Synthesis, optimization and characterization of silver nanoparticles using the catkin extract of Piper longum for bactericidal effect against food-borne pathogens via conventional and mathematical approaches

“…Fatty acids such as hexadecanoic acid are effective against inflammatory disorders and microbial pathogens [71] , [72] , [73] . Extracts that constitute octadecadienoic acid, butenoic acid, propenoic acid and silane derivatives are known to possess antibacterial activities [74] , [75] , [76] , [77] , [78] . This analysis indicates that these constituents observed in the catkin extract has most probably reduced the precursor and likewise encapsulated the nanoparticles leading to enhanced antimicrobial activity compared to the chemically synthesized nanoparticles.…”

Quaternary ammonium silane (k21) based intracanal medicament triggers biofilm destruction

“…3-(Trimethoxysilyl) propyldimethyloctadecyl ammonium chloride (SiQAC) penetrates the bacterial cell membranes via positively charged quaternary amine charged (N +) compounds leading to bacterial lysis due to their interaction with the negatively charged bacterial membranes [ 50 ]. Thus, the current study claimed that the microbial effectiveness of k21 at 2% as minimum concentration required to achieve the desired efficacy and hence could have overcome any shortcomings of existing disinfectants, as per our previous studies [ 24 , 27 ]. Mono-species biofilms have been tested in our study, though studying more complex biofilms is the need of the hour.…”

“…The binding of the quaternary ammonium compound is selective and towards the Sortase A protein within the bacterial membrane via electrostatic and hydrogen bonding coupled with van der Waals’ interactions. The compound interferes with the catalytic activity of Sortase A, resulting in reduced anchoring of cell surface proteins [ 27 , 28 ]. Data suggests, quaternary ammonium compounds are active even at low concentrations [ 29 ].…”