Clostridium tertium Bacteremia: A Marker of an Underlying Perforated Colonic Diverticular Disease in a Non-Neutropenic Patient With COVID-19.

Clostridium tertium (C. tertium) is an aero-tolerant, gram-positive, endospore-forming, and non-exotoxin-producing bacillus that has colonized the gastrointestinal tract of animals and humans. It is considered a rare pathogen of humans, possibly because of its low virulence. Most C. tertium infections in the reviewed literatures were predominately reported among neutropenic hosts with hematological malignancies. A 66-year-old female patient with a past medical history of type II diabetes mellitus and chronic obstructive pulmonary disease was admitted with coronavirus disease 2019 (COVID-19) that initially required non-invasive ventilation. The patient developed septic shock due to C. tertium bacteremia. Computed tomography of the abdomen depicted free intraperitoneal gas and sigmoid colon perforation. Exploratory laparotomy revealed perforated sigmoid diverticulitis, and Hartmann's procedure was performed. The patient received a prolonged course of susceptibility-guided antibiotics to clear C. tertium bacteremia. The authors described a rare case of C. tertium bacteremia as a marker of underlying perforated colonic diverticulitis in a non-neutropenic patient with COVID-19 that necessitated operative procedure intervention for primary source control and an extended course of targeted antibiotic therapy to treat the Clostridial infection. Our case reaffirmed the available literature that suggested the presence of C. tertium bacteremia in non-neutropenic patients raises suspicion of an associated gastrointestinal tract pathology that should warrant a diagnostic workup to identify the infection source culprit.