Removal, Kill, and Transfer of Bacteria from Hands by Antibacterial or Nonantibacterial Soaps After Handling Raw Poultry

Abstract

Hand hygiene is broadly recognized as a critical intervention in reducing the spread of disease-causing pathogens in both professional and personal uses. In this study, the impact of antibacterial (AB) or nonantibacterial soaps on the removal and postwash transfer of E. coli following the handling of raw poultry was assessed. Baseline bacterial contamination ranged between 10⁷ and 10⁹ CFU per hand. Hands were washed for 30 s in 40°C ± 2°C tap water using 2 mL of AB soap (0.5% and 1.0% Chloroxylenol, 0.5% Benzalkonium Chloride, or 4.0% Chlorhexidine Gluconate), non-AB soap (cosmetic/plain soap), or water. Postwash, water, and non-AB soap had a mean 3.63 and 3.65 Log₁₀ reduction of E. coli on hands. AB treatments had a mean 4.19-4.35 Log₁₀ reduction. Rinse water had mean bacterial counts of 8.62 and 8.88 Log₁₀ CFU/mL for non-AB soap and water and 5.37-6.90 Log₁₀ CFU/mL for AB treatments. Bacterial transfer was assessed by following the test subject's handling of a sterile polymer knife handle for 30 s postwash. E. coli transfer ranged from 263 to 903 CFU/handle for AB soaps and 1572 or 1709 CFU/handle for water and non-AB soap. Differences between AB and non-AB treatments were statistically significant (p < 0.0001) for hands and rinse water. Differences in transfer from hands to knife handle were not statistically significant (p = 0.139). Combined, these data highlight significant differences in the performance of AB soaps relative to non-AB soaps in a food handling environment-specific usage example and provide an unexplored assessment of the bactericidal vs. removal effects of AB vs. non-AB soaps on bacteria removed from the hands. These data reinforce the importance of hand hygiene, provide new details on the differences between AB vs. non-AB soaps, and highlight potential differences to inform food handling environment operators and public health personnel on how these products may impact food safety.

Keywords: Antimicrobial; Bacteria; FDA; Food safety; Handwash; Transfer.