Epidemiology and virulence-associated genes of Clostridioides difficile isolates and factors associated with toxin EIA results at a university hospital in Japan

Abstract

Introduction Clostridioides difficile is one of the most important nosocomial pathogens; however, reports regarding its clinical and molecular characteristics from Japan are scarce. Aims We studied the multilocus sequence typing (MLST)-based epidemiology and virulence-associated genes of isolates and the clinical backgrounds of patients from whom the isolates had been recovered. Methods A total of 105 stool samples tested in a C. difficile toxin enzyme immune assay (EIA) were analysed at the University of Tokyo Hospital from March 2013 to July 2014. PCR for MLST and the virulence-associated genes tcdA , tcdB , cdtA , cdtB and tcdC was performed on C. difficile isolates meeting our inclusion criteria following retrospective review of medical records. EIA-positive and EIA-negative groups with toxigenic strains underwent clinical and molecular background comparison. Results The toxigenic strains ST17, ST81, ST2, ST54, ST8, ST3, ST37 and ST53 and the non-toxigenic strains ST109, ST15 and ST100 were frequently recovered. The prevalence rate of tcdA -negative ST81 and ST37, endemic in China and Korea, was higher (11.4%) than that reported in North America and Europe, and hypervirulent ST1(RT027) and ST11(RT078) strains that occur in North America and Europe were not recovered. The linkage between the EIA results and cdt A/B positivity, tcdC deletion, or tcdA variation was absent among toxigenic strains. Compared with the 38 EIA-negative cases, the 36 EIA-positive cases showed that the patients in EIA-positive cases were older and more frequently had chronic kidney disease, as well as a history of beta-lactam use and proton pump inhibitor therapy. Conclusion In Japan, the prevalence rates for tcdA -negative strains are high, whereas the cdtA/B -positive strains are rare. EIA positivity is linked to older age, chronic kidney disease and the use of beta-lactams and proton pump inhibitors.

Use of tcdC gene sequencing to prevent misidentification of Clostridioides difficile ribotype 176 and 027

“…This deletion corre-lated with the detection of C. difficile RT 027 (21). Toxigenic strains possess tcdC gene and non-toxigenic strains do not express it (22). Emergent RTs (RT 027, 176 and 4 -belong to clade 2) caused severe disease and increased morbidity and mortality (23).…”

Clostridioides difficile from Fecally Contaminated Environmental Sources: Resistance and Genetic Relatedness from a Molecular Epidemiological Perspective

“…Heise et al [19] observed that several different RTs belonged to non-toxigenic strains, such as RT010, RT205, RT578, RT629, and RT701 obtained from poultry meat in Germany. Interestingly, non-toxigenic ST109 (RT073) was frequently isolated from humans in Japan [60].…”

Genetic diversity and epidemiology of accessory gene regulator loci in Clostridioides difficile

“…A total of 133 non-duplicate C. difficile clinical isolates were obtained from the University of Tokyo Hospital between 2013 to 2014 [14]. Laboratory reference strains ATCC BAA-1382 and NCTC 13366 (hereafter referred to as CD630 and R20291, respectively) were also subjected to identical isolation methods and subsequent analysis.…”

“…Both clinical and reference lab strains of C. difficile in our study were anaerobically cultured by our previous reported method [14]. C.…”

“…A 100 bp DNA ladder (Toyobo, Osaka, Japan) was used to evaluate product size during gel electrophoresis of PCR amplicons. MLST and toxigenicity analysis were performed as described in previous reports [14–16]. As part of MLST analysis, PCR amplicons underwent DNA sequencing, and STs and clades were determined based on DNA sequencing data using the PubMLST sequence query page (https://pubmlst.org/cdifficile/).…”