Inactivation ofBacillus AnthracisSpores on All-Weather Paper

Abstract

This study evaluated the inactivation of Bacillus anthracisAmes strain on all-weather paper using 1% and 6% sodium hypochlorite (NaOCl). A suspension of approximately 1 x 10 8 colony forming units (CFU) of B. anthracis was dried on paper coupons and exposed to either 1% or 6% NaOCl (with or without the addition of surfactant) by wiping with a bleach-soaked towel or by spraying with a commercially available spray bottle. Contact times of 1-and 20-minutes were evaluated for each concentration of NaOCl, with or without the addition of surfactant (0.1% or 0.01% Triton X-100). In all instances, 6% NaOCl produced higher log reductions (better efficacy) than 1% NaOCl. This was true with or without the addition of surfactant and regardless of contact time. The highest log reduction was observed when 6% NaOCl (without the addition of surfactant) was sprayed and allowed a contact time of 20 minutes. This treatment provided complete inactivation of the B. anthracis spores when compared to positive controls. This study provides information for using all-weather paper in various applications where there is potential for biological contamination and subsequent increased risk to personnel with regard to laboratory-acquired infections within a biocontainment facility.