Reducing Antibiotic Drug Use Effects on Clostridioides difficile Colonization in Nursing Home Residents1.

Antibiotic drug-mediated changes in the human gut microbiota affect Clostridioides difficile colonization. We created a compartmental model of C. difficile colonization in nursing home residents to improve understanding of how the gut microbiota mediates the transmission process. When analyzing C. difficile colonization as a function of the daily percentage of the nursing home resident population on antibiotic drugs, the model displayed increases in C. difficile colonization as antibiotic drug use increased. Reducing the daily percentage of the nursing home resident population receiving antibiotic drugs from 8% to 6.6% could halve endemic colonization. In sensitivity analyses, increases in the time to recover microbiota diversity, duration of colonization, daily percentage of the nursing home resident population on antibiotic drugs, and susceptibility to C. difficile in the low-diversity microbiota population had the largest effect on endemic colonization. Our model demonstrates that reductions in antibiotic drug use yield reductions in C. difficile colonization.