Chronic Diarrhea Caused by a Klebsiella oxytoca Toxin Producer Strain Following Antibiotic-Associated Hemorrhagic Colitis: Successful Treatment by Fecal Microbiota Transplant.

This article focuses on a case of chronic diarrhea caused by toxin-producing strains of Klebsiella oxytoca, a gram-negative bacterium associated with antibiotic-associated hemorrhagic colitis (AAHC), successfully treated with fecal microbiota transplant (FMT). The patient’s symptoms persisted despite multiple antibiotic treatments, but resolved following FMT, which also restored gut microbiota diversity and eliminated the toxigenic K. oxytoca strain. Molecular analyses confirmed the presence of toxin genes encoding tilimycin and tilivalline in the isolated strains, and the study highlights the potential role of FMT in treating non–Clostridioides difficile infectious colitis linked to dysbiosis. This case suggests that FMT may offer therapeutic benefits by restoring microbial balance and suppressing pathogenic bacteria in chronic colitis caused by K. oxytoca.