Prevalence of Non-Toxigenic Clostridioides difficile in Diarrhoea Patients and Their Clinical Characteristics

Non-toxigenic Clostridioides difficile (NTCD) has been shown to decrease the risk of recurrent C. difficile infection (CDI) in patients following metronidazole or vancomycin treatment for CDI. Limited data on the prevalence of NTCD strains in symptomatic patients and their clinical characteristics are available. We conducted this study to investigate the prevalence of NTCD in diarrhoea patients and their clinical characteristics. Between July 2017 and June 2018, unduplicated stool specimens were collected from patients with diarrhoea. The characteristics and episodes of C. difficile infection in patients with NTCD and toxigenic strains were compared. Among the 1182 stool specimens collected, 236 (18.5%) were identified as growing C. difficile, and 19.5% of the identified isolates were found to be NTCD. Multivariate analysis showed that community-onset diarrhoea (OR = 4.13, 95% CI 1.07-15.97; p = 0.040), underlying diabetes (OR = 3.64, 95% CI 1.46-9.25; p = 0.006), previous use of glycopeptides (OR = 4.75, 95% CI 1.37-16.42; p = 0.014), and the lack of use of proton pump inhibitors (PPIs) (OR = 3.57, 95% CI 1.39-9.09; p = 0.009) were independently associated with the NTCD group. Although there was no statistical significance, the number of CDI episodes occurring after 90 days tended to be lower in the NTCD group (2.2%) than in the toxigenic group (11.2%). A considerable portion of the C. difficile strains isolated from patients with diarrhoea showed NTCD. Further, more extensive studies are needed to clearly define the protective effects of NTCD strains in patients with diarrhoea.