Sensitizing Clostridium difficile Spores with Germinants on Skin and Environmental Surfaces Represents a New Strategy for Reducing Spores via Ambient Mechanisms.

Michelle Marie Nerandzic,Curtis J Donskey

doi:10.20411/pai.v2i3.221

Abstract

Background:Clostridium difficile is a leading cause of healthcare-associated infections worldwide. Prevention of C. difficile transmission is challenging because spores are not killed by alcohol-based hand sanitizers or many commonly used disinfectants. One strategy to control spores is to induce germination, thereby rendering the spores more susceptible to benign disinfection measures and ambient stressors.Methods/Results:C. difficile spores germinated on skin after a single application of cholic acid-class bile salts and co-germinants; for 4 C. difficile strains, recovery of viable spores from skin was reduced by ~0.3 log10CFU to 2 log10CFU after 2 hours and ~1 log10CFU to > 2.5 log10CFU after 24 hours. The addition of taurocholic acid to 70% and 30% ethanol significantly enhanced reduction of viable spores on skin and on surfaces. Desiccation, and to a lesser extent the presence of oxygen, were identified as the stressors responsible for reductions of germinated spores on skin and surfaces. Additionally, germinated spores became susceptible to killing by pH 1.5 hydrochloric acid, suggesting that germinated spores that remain viable on skin and surfaces might be killed by gastric acid after ingestion. Antibiotic-treated mice did not become colonized after exposure to germinated spores, whereas 100% of mice became colonized after exposure to the same quantity of dormant spores.Conclusions:Germination could provide a new approach to reduce C. difficile spores on skin and in the environment and to render surviving spores less capable of causing infection. Our findings suggest that it may be feasible to develop alcohol-based hand sanitizers containing germinants that reduce spores on hands.

Highlights

Clostridium difficile is a spore-forming anaerobic bacterium that is the most common cause of healthcare-associated diarrhea in developed countries [1, 2]
The lack of effective strategies to remove spores from skin is of critical importance because healthcare workers frequently contaminate their hands with spores when caring for patients with C. difficile infection (CDI) or asymptomatic carriage of toxigenic C. difficile [8, 9]
Recovery of Clostridium difficile spores from an ex vivo porcine skin model was reduced after sensitizing spores with a single application of germinants

Summary

Introduction

Clostridium difficile is a spore-forming anaerobic bacterium that is the most common cause of healthcare-associated diarrhea in developed countries [1, 2]. Prevention of C. difficile transmission is challenging, in part because the spores are not killed by alcohol-based hand sanitizers, antimicrobial soaps, and many commonly used surface disinfectants [5,6,7]. Spores on the skin of patients and healthcare workers present a particular challenge because sporicidal disinfectants are not safe for use on skin, and soap and water hand washing is only modestly effective in reducing spore contamination [5,6,7]. The lack of effective strategies to remove spores from skin is of critical importance because healthcare workers frequently contaminate their hands with spores when caring for patients with C. difficile infection (CDI) or asymptomatic carriage of toxigenic C. difficile [8, 9]. Prevention of C. difficile transmission is challenging because spores are not killed by alcohol-based hand sanitizers or many commonly used disinfectants. One strategy to control spores is to induce germination, thereby rendering the spores more susceptible to benign disinfection measures and ambient stressors

Methods

Results

Conclusion