Of CE ribotyping profiles were recognized only by
Of 53 CE-ribotyping profiles, 24 were recognized only by the WEBRIBO database and these isolates comprised 11.2% (n=247) of our collection. The occurrence of several WRTs identified in our study (209, 220, 404, 416, 438, 500, 555, AI-12, AI-20, AI-21, AI-75, AI-9-1) has been reported as human clinical isolates (Novak et al., 2015, Indra et al., 2015, Fang et al., 2014, Rafila et al., 2014, Hell et al., 2011, Indra et al., 2008) or as animal isolates WRTs 203, 209, 413, 446, 596, AI-12, AI-60, AI-8/1, AI-9-1 (Janezic et al., 2014, Schneeberg et al., 2013, Indra et al., 2009, Goldová et al., 2012, Indra et al., 2008). Four of these WRTs (AI-82/1, AI-9-1, AI-60, AI-12) have recently been identified in the UK Ribotyping Reference Laboratory (Leeds, UK) as RTs 103, 013, 097 and 150 respectively (Janezic et al., 2014). WRTs AI-82/1, AI-9-1 and AI-60 showed the same ST as was published by Dingle et al. in RTS 103, 013 and 097 (Dingle et al., 2011). WRTs 015 and 002 were assigned as WRTs 015-like and 002-like due to slight changes in their CE-ribotyping profiles; however, the ST of WRT 002-like (ST8) was identical to that of RT 002 in the studies of Knetsch et al. and Dingle et al. (Knetsch et al., 2012, Dingle et al., 2011). The ST of WRT 015-like (ST44) corresponds with the findings of Dingle et al., who identified two STs in RT 015 isolates: ST44-tcdC wild type and ST10, similarly to Knetsch et al. (Knetsch et al., 2012), with the presence of 18bp porcn in the tcdC gene (Dingle et al., 2011). The distribution of isolates depending on the age of the patients revealed the highest ratio of non-toxigenic to toxigenic ribotypes (64:18) and low presence and absence of two predominant toxigenic RTs 001 (1.2%) and 176 (0%) in patients two years old and younger. In other age groups (3–18 years, 19–64 years and ≥65 years), the non-toxigenic and toxigenic isolates ratio decreases (27:76, 33:476 and 53: 1454), while the occurrence of RTs 001 and 176 increases (11.7%, 35.5%, to 56.4%), respectively. The predominant occurrence of RTs 001 and 027 in older population was also found in the study of authors von Müller et al., where RT 027 was not present and RT 001 was present in 9.6% in the group of patients 0–17 years and these ratios increased to 30.7% for RT 027 and 38.6% for RT 001 in the oldest group of patients (>85years), (von Müller et al., 2015). The application of the new CE-ribotyping protocol (Fawley et al., 2015) changed the CE-ribotyping profile in 7.5% of profiles (n=4) with a subsequent change of identification by the WEBRIBO database in two profiles. The WEBRIBO database provides a broad spectrum of available CE-ribotyping profiles, but the raw data are obtained by different protocols (primer design, polymer type) and some of the CE-ribotyping profiles are designated only by a WEBRIBO number or by a combination of letter and number. This stresses the importance of the use of a standardized protocol and also the standardisation of an appropriate dataset of reference C. difficile strains uploaded to the WEBRIBO database.