Clostridium difficile causing pediatric infections: New findings from a hospital-based study in Italy.

Recent studies support a change of Clostridium difficile infections (CDIs) epidemiology in pediatric patients. Since limited information is available about C. difficile in this population, we investigated the epidemiology of CDI in a large pediatric hospital that acts as reference centre in Italy and analyzed C. difficile isolates to identify the prevalent PCR-ribotypes (RTs), the binary toxin (CDT)-positive strains and the antibiotic susceptibility patterns. The CDI incidence was 6.6 cases/1000 admissions and the majority (92%) of CDI were healthcare-associated (47% occurred in the Hematology-Oncology and in the Gastroenterology units). Most of symptomatic children <3 years with a positive culture for C. difficile were negative for other gastrointestinal pathogens, supporting C. difficile as cause of disease in these patients, including those showing recurrences. Strains RT020 (16%) and RT014 (14%) were identified as the main cause of infection, while RT356/607 and RT018, predominant in Italian adult patients, were absent (RT356/607) or rarely found (RT018) among children. CDT-positive strains represented the 20% of the total number of isolates analyzed. In particular, two emerging types, RT033 and RT442, were recognized as Toxin A-/Toxin B-/CDT+. Resistance to antibiotics characterized almost 50% of the toxigenic isolates analyzed in this study and, in particular, 20% of them were multidrug resistant (MDR). The emergence and circulation of strains with peculiar toxins profiles and/or MDR strongly highlight the necessity of a rapid CDI diagnosis, a careful monitoring of C. difficile in pediatric patients and a more strict control of antibiotics usage in the Italian pediatric hospitals.