Antimicrobial Resistance of Clostridioides (Clostridium) difficile in Cambodia

<b>Background/Objectives:</b> Antimicrobial resistance (AMR) remains a major topic of interest in infectious disease management. We studied AMR in <i>Clostridioides difficile</i> isolated in Cambodia. <b>Methods:</b> Agar dilution susceptibility testing was performed according to the CLSI guidelines to determine minimal inhibitory concentrations (MICs) of 10 antimicrobials for 192 isolates of <i>C. difficile</i> from four populations in Cambodia: hospitalised adults, hospitalised children, children from an outpatient department (OPD), and healthy adolescents in the community. <b>Results:</b> Using the CLSI MIC breakpoints for anaerobes and EUCAST breakpoints for <i>C. difficile</i>, all isolates were susceptible to vancomycin, metronidazole, fidaxomicin, and amoxicillin/clavulanic acid, and none were resistant to meropenem. The resistance proportions were for clindamycin, 88% (169/192); tetracycline, 50% (96/192); moxifloxacin, 20% (38/192); and rifaximin, 8% (15/192). Among the 169 clindamycin-resistant isolates, 56.8% (96/169) had an erythromycin MIC of >512 mg/L. Multidrug resistance (MDR) occurred in 20% (39/192) of the isolates, of which 82% (32/39) were non-toxigenic strains. The proportion of MDR varied between collections of isolates from different populations: 28.6% (22/77) in hospitalised adults, 29.8% (14/47) in hospitalised children, 5% (3/59) in OPD children, and none (00/07) in healthy adolescents in the community. <b>Conclusions:</b><i>C. difficile</i> isolates from Cambodia remained susceptible to antimicrobials used to treat <i>C. difficile</i> infection: vancomycin, metronidazole, and fidaxomicin; however, high proportions of resistance to clindamycin and tetracycline were observed. The high number of MDR strains of <i>C. difficile</i> is a threat to AMR management in Cambodia and a factor contributing to the persistent spread of <i>C. difficile</i> in both hospital and community settings.