Whole-genome sequencing reveals nosocomial Clostridioides difficile transmission and a previously unsuspected epidemic scenario

To trace the routes and frequencies of transmission of Clostridioides difficile in a tertiary-care hospital in Madrid (Spain), we sequenced the genomes from all C . difficile isolates collected over 36 months (2014–2016) that were indistinguishable from any other isolate by PCR ribotyping. From a total of 589 C . difficile infection cases, we cultivated and PCR-ribotyped 367 C . difficile isolates (62%), of which 265 were genome-sequenced. Based...