Toxigenic Clostridium perfringens isolated from at-risk pediatric inflammatory bowel disease patients

With the goal of studying mucosal-associated bacteria and products detrimental to inflammatory bowel disease (IBD) patients, we directly cultured bacterial communities from mucosal biopsies and examined for detrimental traits. Focusing on red blood cell lysis, a virulence trait, communities from 5 of 9 patients exhibited hemolytic activity. Clostridium perfringens was isolated from each hemolytic community, and whole-genome sequencing confirmed presence of hemolytic toxins – alpha toxin in all 5 strains, perfringolysin O (PFO) in 4 strains, alveolysin in 2 strains – and absence of enterotoxins. In vitro cytotoxicity experiments demonstrated strain supernatants were toxic to various cell types located beneath the intestinal epithelial barrier, including endothelial, neuroblasts, and neutrophils, while impact on epithelial cells was less pronounced. These findings suggest C. perfringens may be damaging particularly when intestinal barrier integrity is compromised, such as in IBD patients. Further characterization using purified toxins and genetic insertion mutants confirmed PFO toxin was sufficient for cell toxicity. C. perfringens supernatants also induced activation of neuroblast and dorsal root ganglion (DRG) neuron cells in vitro, suggesting C. perfringens in inflamed mucosal tissue may directly contribute to abdominal pain, a frequent IBD symptom. Strikingly, C. perfringens was detected in biopsies of 8 of 9 pediatric patients while not in all corresponding stool samples, and in other datasets, C. perfringens was in stool samples of IBD adults (18.7-27.1%) much more frequently versus healthy (5.1%). Our findings showcase C. perfringens may have an important pathogenic impact on IBD patients. Similar to Clostridioides difficile, routine monitoring of C. perfringens and PFO toxins in patients may be beneficial.

• Type: Metagenomics
• Archiver: European Genome-Phenome Archive (EGA)