Bacterial Fecal Microbiota in Healthy Subjects and Inpatients with Clostridium difficile Infection

摘要

Clostridium difficile is a nosocomial enteric pathogen, considered the main etiological agent of antibiotic-associated diarrhea in hospitals. C. difficile is resistant to several antimicrobial agents used in empiric treatment protocols, which confers selective advantages to this species as compared with other members of the intestinal microbiota. The aim of this study was to evaluate and identify possible alterations of the intestinal microbiota population resulting from the use of antimicrobials associated with infections by C. difficile (CDI). Denaturing Gradient Gel Electrophoresis (DGGE) was used to evaluate fecal samples from two groups: healthy subjects and patients with C. difficile-associated diarrhea (CDAD). A decrease in bacterial diversity was highlighted by the low number of bands in samples from CDAD patients, compared with healthy subjects. This may indicate that antibiotic treatment would affect bacterial diversity, leading to a significant difference between the intestinal microbiota of these two groups, but further studies are still needed. Firmicutes and Verrucomicrobia phyla were detected mainly in healthy individuals, and these could be related to protection factors against the CDI. Klebsiella variicola/K. pneumoniae were found mostly in samples from CDI patients. This study shows the effects of antimicrobials and the CDI itself on human intestinal microbiota.