Analysis of anti-microbial and anti-biofilm activity of hand washes and sanitizers against S. aureus and P. aeruginosa

Objectives: To analyse the biofilm-forming potential of clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa, and to assess antimicrobial activity of commonly used sanitizers in hospital and laboratory settings. Method: The study was conducted at Aga Khan University Karachi from August 2016 to January 2017. The biofilm-forming potential of Staphylococcus aureus and Pseudomonas aeruginosa clinical isolates were evaluated qualitatively using air-liquid interface tube method, and air-liquid interface cover slip assay. The antimicrobial activity of commonly-used hand-washes and sanitizers were assessed using agar well diffusion method, while the anti-biofilm activity of the hand-washes and sanitizers was qualitatively assessed using air-liquid interface cover slip assay. Results: Of the eight hand-washes and sanitizers, 2(25%) showed antimicrobial activity against both Staphylococcus aureus and Pseudomonas aeruginosa, while 2(25%) exhibited antimicrobial activity against either S. aureus or P. aeruginosa. Also, 4 (50%) of them showed no inhibitory activity against S. aureus and P. aeruginosa. Conclusion: The findings shall have important consequences with regards to infection control in hospital and laboratory settings.