Molecular epidemiology of community-onset Clostridioides difficile infections at a tertiary hospital in mainland China: A ten-year (2010-2019) retrospective study

Abstract Background Clostridioides difficile infection (CDI) is an increasingly common disease in healthcare facilities and community settings. However, there are limited reports of community-onset CDI (CO-CDI) in China. We retrospectively analyzed the molecular epidemiology of CO-CDI at a tertiary hospital over a period of 10 years. Methods A total of 1307 stool samples from 1213 outpatients were tested by culturing. The presence of toxin genes ( tcd A , tcd B , cdtA and cdtB ) were confirmed by PCR. Toxigenic strains were typed using multilocus sequence typing (MLST). Susceptibility to 9 antimicrobials was evaluated using the E-test. Results Eighty-nine of 1213 outpatients (7.3%) had CO-CDI, 4 of these patients (4.5%) had one or more recurrence, and there were 95 strains of toxigenic C. difficile . Among these strains, 82 (86.3%) had the tcdA and tcdB genes (A + B+) and 5 of these 82 strains were positive for the binary toxin genes ( cdtA and cdtB ); the other 13 strains (13.7%) had the tcdB gene only (A-B+). There were 15 different STs and the most prevalent were ST-54 (23.2%), ST-35 (16.8%), and ST-2 (13.7%). All strains were susceptible to metronidazole and vancomycin, and had low resistance to moxifloxacin and tetracycline, but had high resistance to ciprofloxacin, clindamycin, and erythromycin. Twenty-three isolates (24.2%) were multidrug-resistant. Conclusions Outpatients with CDI were common during this period in our hospital. The C. difficile isolates had high genetic diversity. All isolates were susceptible to metronidazole and vancomycin, and nearly one quarter of all isolates had multidrug resistance.