Assessment for Sporicidal Activity of Two Types of Peroxygen/Silver-Based Disinfectants: A Comparative Study

Numerous cases have been reported globally showing outbreaks, dissemination of infections and/or spoilage of medicinal products, food and other consumables that affects human life and may lead to death in some cases. One of the most critical measures of microbial contamination that should be taken into consideration is the use of proper disinfectant depending on the type of activities and the work load of the healthcare institution, subjects or media for microbial transfer and the affected population. The current study shows significant difference in sporicidal activity between two types of commercial peroxygen/Silver based disinfectants obtained from same manufacturer and delivered through same distributor at the same time. The peroxygen component in one of the disinfectant products is Hydrogen peroxide while in the other product is Peroxyacetic acid/Hydrogen Peroxide mixture. Preliminary rapid assessment of the disinfectants activity was required using the most resistance microbial form (bacterial spore) as a reference microorganism to challenge the biocidal products. Bacillus pumilus and B. subtilis spores were exposed to both disinfectants at three different concentrations levels covering the range recommended by the manufacturer: 1, 3 and 5% (v/v). The first formula did not exceed 0.5 logarithmic reduction(LR) even after 30 minutes. While the other product achieved more than two folds LR (more than 100 times reduction in microbial population) after ten minutes contact time. Appropriate initial screening of biocidal activity in commercial disinfectants market is critical step that should be performed by the healthcare facilities before practical application. Otherwise, inefficient control on bioburden may lead to devastating consequences on human health. An initial, non-laborious, time-saving and non-expensive screening test using the most resistance microorganisms is encouraged to be performed by healthcare facilities prior to practical application of disinfectant rather than reliance solely on random selection of biocidal agents using informational data without confirmatory experiments