Clostridium, Clostridioides , and Other Clostridia

Abstract

The genus Clostridium comprises obligately anaerobic (or occasionally aerotolerant), Gram‐positive rods commonly found in soil, water, and gastrointestinal tracts of insects and animals, as well as humans. Accurate, definitive identification is needed to better define the role of clostridia in disease, to aid the clinician in selecting optimal treatment, and for public health purposes (e.g., hospital‐acquired Clostridioides difficile disease ). The isolation of a Clostridium species from a clinical specimen, even a blood culture, may or may not be significant clinically, and culture results should be interpreted in relation to the clinical findings for the patient. Identification of clostridia in specimens from sites of infection due to mixed organisms can be time‐consuming and expensive. Typing of Clostridioides difficile fosters understanding of the epidemiology of infections and has become increasingly important with the emergence of outbreaks caused by hypervirulent strains.