Molecular epidemiology and antimicrobial susceptibility of Clostridium difficile isolates from two Korean hospitals

Abstract

Clostridium difficile is one of the main etiological agents causing antibiotic-associated diarrhea. This study investigated the genetic diversity of 70 toxigenic C. difficile isolates from two Korean hospitals by employing toxinotyping, ribotyping, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Toxin gene amplification resulted in 68 A⁺B⁺ and two A-B+ isolates. Most isolates (95.7–100%) were susceptible to daptomycin, metronidazole, and vancomycin. Seventy C. difficile isolates were classified into five toxinotypes, 19 ribotypes, 16 sequence types (STs), and 33 arbitrary pulsotypes. All C. difficile isolates of ribotype 018 (n = 38) were classified into ST17, which was the most prevalent ST in both hospitals. However, C. difficile isolates of ST17 (ribotype 018) exhibited pulsotypes that differed by hospital. ST2 (ribotype 014/020), 8 (ribotypes 002), 17 (ribotype 018), and 35 (ribotypes 015) were detected in both hospitals, whereas other STs were unique to each hospital. Statistical comparison of the different typing methods revealed that ribotyping and PFGE were highly predictive of STs. In conclusion, our epidemiological study indicates that C. difficile infections in both hospitals are associated with the persistence of endemic clones coupled with the emergence of many unique clones. A combination of MLST with PFGE or ribotyping could be useful for monitoring epidemic C. difficile strains and the emergence of new clones in hospitals.

Molecular epidemiology of Clostridioides (previously Clostridium) difficile isolates from a university hospital in Minas Gerais, Brazil

“…ST2, all classified as RT014/020, was the second most common strain. This finding is also in accordance with previous studies which indicates RT014/020 as a worldwide disseminated ribotype (Sundram et al, 2009;Weber et al, 2013;Yan et al, 2013;Cheng et al, 2015;Kuwata et al, 2015;Nicholas et al, 2017).…”

“…Of these six novel STs, four were also identified as new ribotypes ( Table 1). The diversity found in the present study seems to be higher than previously reported in other hospitals elsewhere (Weber et al, 2013;Kuwata et al, 2015;Cheng et al, 2015;Nicholas et al, 2017;Wang et al, 2017;Chen et al, 2018). Some studies have showed a link between the high diversity of ribotypes and less occurrence of CDI by RT027 and RT078 (Freeman et al, 2015;Rodriguez et al, 2016).…”

Molecular epidemiology of <em>Clostridium difficile</em> in two tertiary care hospitals in Shandong Province, China

“…For example, in Korea and Japan, ST17 is the predominant type (55.7% and 21.5%, respectively), followed by ST2 (8.6% and 10.0%, respectively). 30 , 31 However, in Europe, RT027/ST1 is the most prevalent genotype, especially in Western and Eastern Europe. 32 …”

Clostridium difficile Infection: An Epidemiology Update

“…• Increased inflammation C. difficile RTs are geographically distributed by nation and region, but also by hospital. 103 The population of C. difficile RTs is expansive, but dominated by a few RTs, and population balance changes over time. 104,105 A few major strains, as follows, are dominant: BI/NAP1/027, 014, 001/072, and 078 predominated in a population of 99 RTs identified in European stool samples.…”