An ecological snapshot of Clostridioides difficile: characterizing genetic diversity of C. difficile within Banner-University Medical Center Phoenix

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine.RATIONALE: The genetic diversity of Clostridioides difficile within hospitals is known to vary geographically: the C. difficile ecology within Banner-University Medical Center Phoenix (BUMCP) is uncharacterized. METHODS: A laboratory-based surveillance study design was used unique to-be-discarded stool samples testing positive for C. difficile infection (CDI) at BUMCP per their existing testing protocol were collected and banked over a 16 month period. Each deidentified sample underwent selection and culture before being prepared for and subjected to capillary PCR in order to determine genetic type (ribotype) of each offending strain of C. difficile. RESULTS: A total of 267 samples met inclusion criteria for this study; 225 were successfully genetically typed, and 83 unique ribotypes were identified. 17 ribotypes (20.5%) are responsible for 60.5% of all typeable cases of CDI during the study period, while 43 strains (51.8%) were each represented by only one case (15.1% of typeable cases) and another 23 strains (27.7%) were represented by two cases (20.4% of typable cases). CONCLUSIONS: There is an uneven distribution of disease burden relative to ribotype. This finding is consistent with similar investigations in other geographies. The highest burdens of disease are attributable to ribotypes 027, 106 and 176 – all well-documented hypervirulent outbreak associated strains.This item is part of the College of Medicine - Phoenix Scholarly Projects 2020 collection. For more information, contact the Phoenix Biomedical Campus Library at pbc-library@email.arizona.edu