An optimized co-formulation minimized quaternary ammonium compounds adsorption onto raw cotton disposable disinfecting wipes and maintained efficacy against methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis, and Pseudomonas aeruginosa

Abstract

The transmission of infectious agents can occur through secondary routes by contact with contaminated inanimate objects in clinical and food service settings. Effective disinfection of exposed surfaces can aid in reducing secondary transmission of infectious agents. Quaternary ammonium compounds (quats) are biocides widely used as active ingredients in disinfecting solutions and are effective against a wide range of microorganisms, including those with antibiotic resistance. Cellulosic fibers such as cotton are desirable as disposable substrates for the application of disinfecting solutions, since they have good absorbency and cleaning properties and are sustainable and biodegradable. However, cotton fibers deplete quats from solution through strong ionic interactions at the solid–liquid interface, thereby reducing the amount of quat deposited onto a surface for effective disinfection. In this study, we used response surface methodology to model the depletion of the quat, alkyldimethylbenzylammonium chloride (ADBAC), onto cotton wipe substrates in the presence of chemical compounds that interfered or competed with the ionic interactions between the quat and the cotton fiber surface. Preliminary efficacy testing successfully demonstrated that an optimized disinfecting ADBAC co-formulation applied with a raw cotton disposable wipe maintained efficacy against representative gram negative ( Pseudomonas aeruginosa) and gram positive ( Staphylococcus aureus) bacteria compared to a control disinfecting solution containing only ADBAC. Our optimized disinfecting ADBAC co-formulation remained efficacious against Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococcus faecalis, demonstrating for the first time that quat adsorption onto cotton substrates can be minimized and efficacy maintained with inexpensive added chemistries.