Antimicrobial effects of an organosilane-based disinfectant

Organosilane-based disinfectants have been purported to impart lasting antimicrobial properties when applied to a surface. The implications being dramatic reduction in pathogen transmission via fomites and therefore of great public health importance as a means to limit the spread of outbreaks such as COVID-19. We conducted experiments in our laboratory to assess the efficacy of one such product, which reported anti-microbial protection of up to 120 days, as an operational report for our hospital. 1) The organosilane product was applied on a Mueller Hinton agar plate and left overnight underneath an airconditioned vent to promote mould growth. 2) The organosilane product was applied on a Blood Agar Plate (BAP) that was inoculated with E. Coli and observed over 24 hours. 3) Lastly, the organosilane coating was applied onto plastic plates to simulate hospital ward surfaces. Simulated pathogens (suspension of oral commensals) were spread across the plastic plates, swabbed at 1 hour, 8 hours and 24 hours and then incubated for 24 hours. In all 3 experiments, there was no significant difference in microbial growth between the control and intervention arms. Although our experiments did not assess different methods of application nor effect on different materials applied, the lack of demonstrable effects of the organosilane product calls for caution against widespread use of a product whose claims are unverified.