Significance and Impact of the Study: Clostridioides difficile spores survive on healthcare linens during industrial laundering. This study demonstrates that C. difficile spores are resistant to thermal and chemo-thermal disinfection parameters recommended for healthcare laundry in the UK. The interactions between soiling, heat and disinfectants on C. difficile spore inactivation were established, which may aid in optimization of healthcare laundry processes. Clostridioides difficile spores attached to cotton over time, with the exosporium playing a role in adherence. These findings may inform novel strategies to prevent attachment to textiles, improving spore removal from linen by detergents during laundering.

Abstract

Clostridioides difficile spores were previously demonstrated to survive industrial laundering. Understanding interactions between heat, disinfectants and soiling (e.g. bodily fluids) affecting C. difficile spore survival could inform the optimization of healthcare laundry processes. Reducing spore attachment to linen could also enhance laundering efficacy. This study aimed to compare the sensitivity of C. difficile spores to heat and detergent, with and without soiling and to investigate adherence to cotton. Survival of C. difficile spores exposed to industrial laundering temperatures (71–90°C), reference detergent and industrial detergent was quantified with and without soiling. The adherence to cotton after 0 and 24 h air drying was determined with the exosporium of C. difficile spores partially or fully removed. Clostridioides difficile spores were stable at 71°C for 20 min (≤0·37 log₁₀ reduction) while 90°C was sporicidal (3 log₁₀ reduction); soiling exerted a protective effect. Industrial detergent was more effective at 71°C compared to 25°C (2·81 vs 0·84 log₁₀ reductions), however, specifications for sporicidal activity (>3 log₁₀ reduction) were not met. Clostridioides difficile spores increasingly adhered to cotton over time, with 49% adherence after 24 h. Removal of the exosporium increased adherence by 19–23% compared to untreated spores. Further understanding of the role of the exosporium in attachment to cotton could enhance spore removal and aid decontamination of linen.