Molecular characterisation of Czech Clostridium difficile isolates collected in 2013-2015

Clostridium difficile is a leading nosocomial pathogen and molecular typing is a crucial part of monitoring its occurrence and spread. Over a three-year period (2013-2015), clinical C difficile isolates from 32 Czech hospitals were collected for molecular characterisation. Of 2201 C difficile isolates, 177 (8%) were non-toxigenic, 2024 (92%) were toxigenic (tcdA and tcdB) and of these, 677 (33.5%) carried genes for binary toxin production (cdtA, cdtB). Capillary-electrophoresis (CE) ribotyping of the 2201 isolates yielded 166 different CE-ribotyping profiles, of which 53 were represented by at least two isolates for each profile. Of these, 29 CE-ribotyping patterns were common to the Leeds-Leiden C. difficile reference strain library and the WEBRIBO database (83.7% isolates), and 24 patterns were recognized only by the WEBRIBO database (11.2% isolates). Isolates belonging to these 53 CE-ribotyping profiles comprised 94.9% of all isolates. The ten most frequent CE-ribotyping profiles were 176 (n=588, 26.7%), 001 (n = 456, 20.7%), 014 (n=176, 8%), 012 (n =127, 5.8%), 017 (n =85,3.9%), 020 (n= 68, 3.1%), 596 (n = 55, 2.5%), 002-like (n = 45, 2.1%), 010 (n =35, 1.6%) and 078 (n=34, 1.6%). Multi-locus sequence typing (MIST) of seven housekeeping genes performed in one isolate of each of 53 different CE-ribotyping profiles revealed 40 different sequence types (STs). We conclude that molecular characterisation of Czech C difficile isolates revealed a high diversity of CE-ribotyping profiles; the prevailing RTs were 001 (20.7%) and 176 (027-like, 26.7%). (C) 2016 Elsevier GmbH. All rights reserved.