Recovery of Clostridioides difficile from the environment in low resource settings

Clostridioides difficile spores remain viable in the environment for months to years. To detect C. difficile spores in the environment, many studies have used Polywipe™ sponges to wipe surfaces and subsequently extract and culture C. difficile. This study aimed to evaluate a new simpler, cheaper method utilising an alcohol wipe, suitable for low-resource settings. From February to March 2022, Polywipe™ sponges and alcohol wipes were used to swab surfaces in a microbiology laboratory that specialised in working on C. difficile. Culture in Robertson's cooked meat broth (CMB) and supplemented brain heart infusion broth (BHIB-S), both incubated aerobically to mimic conditions in low resource settings where neither anaerobe jars nor chambers were available, was compared. The overall prevalence of C. difficile contamination in the anaerobe laboratory was 3.4% (17/500). Recovery for alcohol wipes and Polywipe™ sponges was 3.2% and 3.6%, respectively, not significantly different. Alcohol wipes inoculated into CMB recovered 80% of C. difficile when there was ∼100 CFU inoculated, and recovery was 100% with a 300 CFU inoculum. BHIB-S recovered only 40% of C. difficile with a 300 CFU inoculum. While BHIB-S successfully recovered C. difficile from all known positive human stool samples (100%, 10/10), outperforming CMB which recovered 80% (8/10), the observed difference was not statistically significant (p = 0.143). Alcohol wipes could be used in low resource settings to recover C. difficile spores from the environment. CMB is a good enrichment medium to use with alcohol wipes as it is transportable around the world at ambient temperature with little impact.