Clostridioides difficile spores tolerate disinfection with sodium hypochlorite disinfectant and remain viable within surgical scrubs and gown fabrics

Abstract

Clostridioides difficile is the most common cause of antibiotic-associated diarrhoea globally. Its spores have been implicated in the prevalence of C. difficile infection due to their resistance and transmission ability between surfaces. Currently, disinfectants such as chlorine-releasing agents (CRAs) and hydrogen peroxide are used to decontaminate and reduce the incidence of infections in clinical environments. Our previous research demonstrated the ability of C. difficile spores to survive exposure to recommended concentrations of sodium dichloroisocyanurate in liquid form and within personal protective fabrics such as surgical gowns; however, the present study examined the spore response to clinical in-use concentrations of sodium hypochlorite. Spores were exposed to a 10 min contact time of 1000, 5000 and 10 000 p.p.m. sodium hypochlorite, and spore recovery was determined. To understand whether biocide-exposed spores transmitted across clinical surfaces in vitro, biocide-exposed spores were spiked onto surgical scrubs and patient gowns and recovery was determined by a plate transfer assay. Scanning electron microscopy was used to establish if there were any morphological changes to the outer spore coat. The results revealed that viable biocide-exposed C. difficile spores can be recovered from surgical scrubs and patient gowns, with no observable changes to spore morphology, highlighting the potential of these fabrics as vectors of spore transmission. This study demonstrates that alternative strategies should be urgently sought to disinfect C. difficile spores to break the chain of transmission in clinical environments.

Comment on the effectiveness of sodium hypochlorite against Clostridioides difficile spores

“…Our findings provide reassurance that EPA-registered sodium hypochlorite disinfectants remain effective against C. difficile spores, including an isolate recently reported to exhibit tolerance to sodium hypochlorite (R20291) [3]. In previous studies, EPA-registered chlorine-releasing products have been shown to be effective in reducing spores on surfaces in clinical settings [15, 16].…”

“…commercial product registered with the EPA as a sporicide versus a preparation not registered as a disinfectant) or test methods. For example, shows variable results for spores of the R20291 isolate in several studies evaluating chlorine-releasing agents [3–5, 9–12], with several studies demonstrating that chlorine-releasing disinfectants remain effective [9–11]. Given these considerations, more information on the sodium hypochlorite formulation (i.e.…”

“…Many chlorine-releasing products are registered by the United States Environmental Protection Agency (EPA) for use against C. difficile spores based on required laboratory testing data [ 2 ]. However, Ahmed and Joshi [ 3 ] recently reported that spores from three strains of C. difficile were minimally reduced after a 10 min exposure to sodium hypochlorite, although the preparation tested was not an EPA-registered sporicidal product and a standardized test protocol was not used [ 2 ]. This report and two other recent publications have raised concern that strains of C. difficile with reduced susceptibility to chlorine-releasing disinfects may be emerging [ 4 5 ].…”

Comments on the tolerance of Clostridioides difficile spores to disinfection with sodium hypochlorite disinfectant

“…We read with interest the article by H. Ahmed and L.T. Joshi about the tolerance of Clostridioides difficile (CD) spores to disinfection with sodium hypochlorite disinfectant [ 1 ]. As reported in this study, the susceptibility of CD spores to chemical disinfectant is of paramount importance because the hospital environment is highly contaminated with C. difficile spores and can be a source of infection, especially in an outbreak setting [ 1 ].…”

“…Joshi about the tolerance of Clostridioides difficile (CD) spores to disinfection with sodium hypochlorite disinfectant [ 1 ]. As reported in this study, the susceptibility of CD spores to chemical disinfectant is of paramount importance because the hospital environment is highly contaminated with C. difficile spores and can be a source of infection, especially in an outbreak setting [ 1 ]. The 2014 IDSA/APIC and 2018 ESCMID guidelines advocate for the use of hypochlorite or chlorine releasing agent for room disinfection of C. difficile infection (CDI) patients [ 2 3 ].…”