title: Variation in germination of Clostridium difficile clinical isolates correlates to disease severity.
abstract: Over the past two decades, Clostridium difficile infections have been increasing in both number and severity throughout the world. As with other spore forming bacteria, germination is a vital step in the life cycle of this pathogen. Studies have examined differences in sporulation and toxin production among a number of C. difficile clinical isolates; however, few have examined differences in germination and the relationship between this phenotype and disease severity. Here, over 100 C. difficile isolates from the University of Michigan Health System were examined for overall germination in response to various combinations of known germinants (taurocholate) and co-germinants (glycine and histidine). Significant variation was observed among isolates under all conditions tested. Isolates representing ribotype 014-020, which was the most frequently isolated ribotype at our hospital, exhibited increased germination in the presence of taurocholate and glycine when compared to isolates representing other ribotypes. Interestingly, isolates that caused severe disease exhibited significantly lower germination in response to minimal germination conditions (taurocholate only), indicating increased control over germination in these isolates. These data provide a broad picture of C. difficile isolate germination and indicate a role for precise control of germination in disease severity.
authors: Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA.
authors: Paul E
authors: PE
authors: Carlson
authors: Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA.
authors: Alyssa M
authors: AM
authors: Kaiser
authors: Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA.
authors: Sarah A
authors: SA
authors: McColm
authors: Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA.
authors: Jessica M
authors: JM
authors: Bauer
authors: Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, Ann Arbor, MI 48109, USA.
authors: Vincent B
authors: VB
authors: Young
authors: Division of Infectious Diseases, Department of Medicine, Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
authors: David M
authors: DM
authors: Aronoff
authors: Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address: pchanna@umich.edu.
authors: Philip C
authors: PC
authors: Hanna
mesh_terms: D016360:Clostridioides difficile / Q000302:isolation & purification / Q000502:physiology*; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis / Q000382:microbiology*; D006801:Humans; D012720:Severity of Illness Index; D013171:Spores, Bacterial
keywords: Clostridium difficile; Germination; NAP1/027; Ribotype; Spore