The Influence of Interfering Substances on the Antimicrobial Activity of Selected Quaternary Ammonium Compounds

Abstract

Standard cleaning processes may not remove all the soiling typically found in food industry, such as carbohydrates, fats, or proteins. Contaminants have a high impact in disinfection as their presence may reduce the activity of disinfectants. The influence of alginic acid, bovine serum albumin, yeast extract, and humic acids was assessed on the antimicrobial activities of benzalkonium chloride and cetyltrimethyl ammonium bromide against Bacillus cereus vegetative cells and Pseudomonas fluorescens. The bacteria (single and consortium) were exposed to surfactants (single and combined) in the absence and presence of potential disinfection interfering substances. The antimicrobial effects of the surfactants were assessed based on the bacterial respiratory activity measured by oxygen uptake rate due to glucose oxidation. The tested surfactants were efficient against both bacteria (single and consortium) with minimum bactericidal concentrations ranging from 3 to 35 mg·L−1. The strongest effect was caused by humic acids that severely quenched antimicrobial action, increasing the minimum bactericidal concentration of the surfactants on P. fluorescens and the consortium. The inclusion of the other interfering substances resulted in mild interferences in the antibacterial activity. This study clearly demonstrates that humic acids should be considered as an antimicrobial interfering substance in the development of disinfection strategies.

Antimicrobial and Antibiofilm N-acetyl-L-cysteine Grafted Siloxane Polymers with Potential for Use in Water Systems

“…Numerous studies have confirmed that organic matter interferes with the activity of antimicrobials [36,37,38]. The interaction between organic matter and antimicrobial substance leads to reduced antimicrobial activity.…”

Molybdenum doped titanium dioxide photocatalytic coatings for use as hygienic surfaces: the effect of soiling on antimicrobial activity

“…This will be investigated in future work. Likewise, Fujishima et al (2000) state that photocatalysts are not especially useful at breaking down large volumes of soilage, but they are capable of destroying it as it accumulates, and Araújo et al (2013) report on how, in the presence of interfering substances, the antimicrobial effectiveness of quaternary ammonium compounds was reduced and depended on the type of interfering substance. To the authors' knowledge, no other reports have been published specifically relating to the effect a brewery soil on a TiO 2 -Mo photocatalytic surface has on microbial numbers.…”

Role of interfering substances in the survival of coronaviruses on surfaces and their impact on the efficiency of hand and surface disinfection

“…An important consideration in the strict compliance of these recommendations is the finding in several studies that interfering substances (including body secretions) could have a strong impact on the efficiency of a disinfectant (27, 28). To simulate clean/dirty environments, standardized interfering substances are used to evaluate disinfection product efficiency according to Phase 2 EN standards.…”