Antimicrobial susceptibility of Clostridioides difficile isolated from diarrhoeal stool specimens of Canadian patients: summary of results from the Canadian Clostridioides difficile (CAN-DIFF) surveillance study from 2013 to 2017. (15th April 2020)

• Record Type: Journal Article
• Authors: Karlowsky, James A; Adam, Heather J; Baxter, Melanie R; Dutka, Christopher W; Nichol, Kim A; Laing, Nancy M; Golding, George R; Zhanel, George G
• Is Part Of: Journal of antimicrobial chemotherapy. Volume 75:Number 7(2020)
• Page Start: 1824
• Page End: 1832
• Publication Date: 2020-04-15
• Subjects: Anti-infective agents -- Periodicals; Chemotherapy -- Periodicals; 615.58
• DOI: 10.1093/jac/dkaa118
• Languages: English
• ISSNs: 0305-7453

Abstract

Abstract: Objectives: To summarize data generated by the Canadian Clostridioides difficile (CAN-DIFF) surveillance study from 2013 to 2017. Methods: Isolates of C. difficile ( n = 2158) were cultured from toxin-positive diarrhoeal stool specimens submitted by eight hospital laboratories to a coordinating laboratory. Antimicrobial susceptibility testing was performed according to the CLSI agar dilution method (M11, 2018). Isolate ribotypes were determined using an international, standardized, high-resolution capillary gel-based electrophoresis protocol. Results: Of the 2158 isolates of C. difficile, 2133 (98.8%) had vancomycin MICs ≤2 mg/L [i.e. were vancomycin susceptible (EUCAST breakpoint tables, v 9.0, 2019) or WT (CLSI M100, 29th edition, 2019)]. Fidaxomicin MICs were lower than those of all other agents tested (MIC90, 0.5 mg/L); however, one isolate with a fidaxomicin MIC of >8 mg/L was identified. Metronidazole MICs ranged from 0.12 to 4 mg/L; all isolates were metronidazole susceptible by the CLSI breakpoint (≤8 mg/L) compared with 96.8% susceptible by the EUCAST breakpoint (≤2 mg/L). In total, 182 different ribotypes were identified from 2013 to 2017. The most common ribotypes identified were 027 (19.3% of isolates) and 106 (8.2%). Ribotype 027 isolates were frequently moxifloxacin resistant (87.3% of isolates) and MDR (48.6%), associated with vancomycin (10/25, 40.0%) and metronidazole (58/69, 84.1%) resistance and from patients aged ≥80 years. The prevalence of ribotype 027 decreased significantly ( P < 0.0001) from 2013 (27.5%) to 2017 (9.0%) and was replaced by increases in ribotype 106 ( P = 0.0003) and multiple less common ribotypes. Conclusions: Periodic surveillance is required to monitor clinical isolates of C. difficile for changes to in vitro susceptibility testing profiles and ribotype evolution.