Unlocking the Sporicidal Potential of Ethanol: Induced Sporicidal Activity of Ethanol against Clostridium difficile and Bacillus Spores under Altered Physical and Chemical Conditions

• Published in: PloS one Vol. 10; no. 7; p. e0132805
• Main Authors: Nerandzic, Michelle M, Sunkesula, Venkata C K, C, Thriveen Sankar, Setlow, Peter, Donskey, Curtis J
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 15.07.2015; Public Library of Science (PLoS)
• Subjects: Acidification; Alcohol use; Alcoholic beverages; Alcohols; Animals; Anti-Bacterial Agents - pharmacology; Antimicrobial agents; Bacillus; Bacillus anthracis - drug effects; Bacillus anthracis - physiology; Bacillus cereus; Bacteria; Clostridium difficile; Clostridium difficile - drug effects; Clostridium difficile - physiology; Cross infection; Ethanol; Ethanol - pharmacology; Formulations; Hands; Health aspects; Health care; Heat resistance; Hydrogen-Ion Concentration; Hygiene; Ionic strength; Methods; Microbial Sensitivity Tests; Osmolar Concentration; Patients; Personal hygiene; Proteins; Sanitizers; Skin; Skin - microbiology; Soaps; Spore coats; Spores; Spores, Bacterial - drug effects; Studies; Sus scrofa; Temperature; Veterans
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0132805

Due to their efficacy and convenience, alcohol-based hand sanitizers have been widely adopted as the primary method of hand hygiene in healthcare settings. However, alcohols lack activity against bacterial spores produced by pathogens such as Clostridium difficile and Bacillus anthracis. We hypothesized that sporicidal activity could be induced in alcohols through alteration of physical or chemical conditions that have been shown to degrade or allow penetration of spore coats. Acidification, alkalinization, and heating of ethanol induced rapid sporicidal activity against C. difficile, and to a lesser extent Bacillus thuringiensis and Bacillus subtilis. The sporicidal activity of acidified ethanol was enhanced by increasing ionic strength and mild elevations in temperature. On skin, sporicidal ethanol formulations were as effective as soap and water hand washing in reducing levels of C. difficile spores. These findings demonstrate that novel ethanol-based sporicidal hand hygiene formulations can be developed through alteration of physical and chemical conditions.