Background
The spore-forming bacterium
Bacillus anthracis
causes anthrax, an often-fatal infection in animals. Therefore, a rapid and reliable strategy to decontaminate areas, humans, and livestock from
B. anthracis
is very critical.
Objectives
The aim of this study was performed to evaluate the efficacy of sodium hypochlorite, calcium hypochlorite, and quaternary ammonium compound (QAC) sanitizers, which are commonly used in the food industry, to inhibit spores and vegetative cells of
B. anthracis
surrogate.
Methods
We evaluated the efficacy of sodium hypochlorite, calcium hypochlorite, and a QAC in inhibiting vegetative cells and spores of a
B. anthracis
surrogate. We treated a 0.1-mL vegetative cell culture or spore solution with 10 mL sanitizer. The samples were serially diluted and cultured.
Results
We found that 50 ppm sodium hypochlorite (pH 7), 1 ppm calcium hypochlorite, and 1 ppm QAC completely eliminated the cells in vegetative state. Exposure to 3,000 ppm sodium hypochlorite (pH 7) and 300 ppm calcium hypochlorite significantly eliminated the bacterial spores; however, 50,000 ppm QAC could not eliminate all spores.
Conclusions
Calcium hypochlorite and QAC showed better performance than sodium hypochlorite in completely eliminating vegetative cells of
B. anthracis
surrogate. QAC was ineffective against spores of the
B. anthracis
surrogate. Among the three commercial disinfectants tested, calcium hypochlorite most effectively eliminated both
B. anthracis
vegetative cells and spores.