Authors: Tinchun Chu, Lee H. Lee, Theresa Aponte, Sabrina Lopez, Giselle Lalata, Gabriela Herrera, Ayuni Yussof, Douglas Dickinson, Stephen Hsu
Bacterial spores are resistant to harsh environments and to currently used hand hygiene products. Infections caused by spore-forming bacteria, which often occur in healthcare settings, long-term care facilities, food and beverage industries, are associated with high morbidity and mortality in the United States. The current recommendation from the US Center for Disease Control and Prevention (CDC) to prevent the spread of bacterial spores is to wash hands with soap and water. However, it is known that soap and water do not inactivate bacterial spores, but rather remove them from the skin into the water drainage system. Although there is a trend towards a reduction of healthcare associated infections (HAI) in the United States, spore-forming bacteria, such as Clostridium difficile (C difficile)
and Bacillus cereus (B. cereus), still pose significant risks to the population. Thus, hand hygiene methods with high sporicidal activity, yet without toxicity, are needed to better protect the general population from infections caused by spore-forming bacteria. We reported previously that derivatives of green tea polyphenols, especially lipid-soluble green tea polyphenols such as EGCG-acyl esters, exhibit potential as sporicidal agents without toxicity to humans or the environment. We hypothesize that alcohol (ethanol) formulated with lipid-soluble EGCG and other plantderived ingredients would achieve high sporicidal efficacy and become novel hand/surface disinfectants without toxicity. The objective of the current study was to determine if alcohol/EGCG-Palmitate (EGCG-P) formulations containing plant-derived ingredients are able to inactivate B. cereus spores effectively as a basis for future hand hygiene purposes. Methods used included suspension testing of different formulations against purified B. cereus spores and quantification of spore germination. The results demonstrated that several formulations containing only plant-derived ingredients were capable of reducing spore germination by greater than 10,000 fold (log 4 reduction) after 60-second exposure. Additional proof-of-concept studies are warranted to explore the suitability of these formulations for future hand hygiene products against spore-forming bacteria.