Metagenomic analysis of the DNA virome of faeces from patients affected by diarrhoea, with suspicion of infection by Clostridium difficile.

Faecal samples were collected from patients with diarrhoea treated at the Hospital Clínico Universitario in Valencia (Valencia, Spain), from 2011 to 2012. Originaly, samples were collected and used to perform metabolic profiling on the gut microbiota of patients with C. difficile that produced or not toxins and on non-colonised control patients, all of them experiencing diarrhoea.Samples consisted of faeces (n=12) from 12 different patients that had been previously diagnosed for the presence of the C. difficile and of the toxins A and B (kit Techlab C. DIFF Quik Chek Complete).Accoding to both varaibles, patients were classified as Clostridium difficile postive/negative and toxin positive/negative.Using 16S rRNA gene sequence analysis, other bacteria had been identified as putative diarrhoea-causing pathogens in the negative/negative cases.For all samples, the metagenomic analysis of the DNA viral communities was carried out, using the Illumina MiSeq with 300 bp x2 chemistry.