Predominance of PCR-ribotypes, 018 (smz) and 369 (trf) of Clostridium difficile in Japan: a potential relationship with other global circulating strains? Senoh, Mitsutoshi and Kato, Haru and Fukuda, Tadashi and Niikawa, Akiko and Hori, Yoshiko and Hagiya, Hideharu and Ito, Yoichiro and Miki, Hiroshi and Abe, Yoshifumi and Furuta, Kiyoshi and Takeuchi, Hideki and Tajima, Hirokazu and Tominaga, Harumi and Satomura, Hideyuki and Kato, Hideaki and Morita, Sayuri and Tanada, Ai and Hara, Toshinori and Kawada, Miki and Sato, Yuka and Takahashi, Masahiko and Higuchi, Akiko and Nakajima, Tomoko and Wakamatsu, Yukiko and Toyokawa, Masahiro and Ueda, Akiko and Roberts, Paul and Miyajima, Fabio and Shibayama, Keigo,, 64, 1226-1236 (2015), doi = https://doi.org/10.1099/jmm.0.000149, publicationName = Microbiology Society, issn = 0022-2615, abstract= Global spread and evolutionary links of an epidemic Clostridium difficile strain (PCR-ribotype 027) have been noted in recent decades. However, in Japan, no outbreaks caused by type 027 have been reported to date. A total of 120 C. difficile isolates from patients at 15 hospitals during non-outbreak seasons between 2011 and 2013 as well as 18 and 21 isolates collected from two hospitals in 2010 and 2009, respectively, in outbreak periods in Japan, were examined. Among these 120 isolates, Japan-ribotypes smz and ysmz (subtype variant of smz) were the most predominant (39.2 %) followed by Japan-ribotype trf (15.8 %). Types smz/ysmz and trf were also concurrently predominant at two hospitals in the outbreak settings. Out of the five binary toxin-positive isolates observed, only one was PCR-ribotype 027 and another PCR-ribotype 078. Type smz was later found to correspond to PCR-ribotype 018. High rates of resistance against gatifloxacin, moxifloxacin, erythromycin and clindamycin were observed in the PCR-ribotype 018 isolates. Interestingly, all trf isolates were toxin A-negative, toxin B-positive, but they did not correspond to PCR-ribotype 017, thus being assigned a new ribotype (PCR-ribotype 369). In conclusion, PCR-ribotypes 018 (smz) and 369 (trf) were identified as major circulating strains in both outbreak and non-outbreak settings in Japan. Given their epidemiological relevance, molecular investigations are warranted to clarify potential evolutionary links with related strains found elsewhere, such as PCR-ribotypes 018 and 017 from Europe and North America., language=, type=