A Study on the Efficacy of Alcohol Based and Alcohol Free Hand Sanitizers Available in the Market Against Staphylococcus Aureus and Salmonella Typhimurium

Hand sanitizers can be manufactured in the form of alcohol based hand sanitizer (ABHS) that contains alcohol, or alcohol free hand sanitizer (AFHS) containing benzalkonium chloride. This study determines the efficacy of ABHS and AFHS products against Staphylococcus aureus and Salmonella Typhimurium. Agar well diffusion assay was performed against the bacterial colonies grown on Mueller Hinton agar in triplicates. Wells were made by punching holes onto the agar and filled with three different brands of hand sanitizers namely 70% ABHS, 95% ABHS, and AFHS. The diameters for zone of inhibition was measured after 24 hours incubation at 37 ℃. Only AFHS product inhibited the growth of S. aureus and S. Typhimurium, whereas 70% and 95% ABHS did not exhibit any zone of inhibition. Although AFHS was proven to be useful, this finding suggests that ABHS available in the market might not necessarily be effective against S. aureus and S. Typhimurium.