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The Department of Pathology’s Sixto M. Leal, M.D., Ph.D., Assistant Professor, Division of Laboratory Medicine, has received a 2020 CCTS Interdisciplinary Network Pilot Award of $60,000 from the Center for Clinical and Translational Science (CCTS) and the UAB Department of Pathology. Dr. Leal received the award after submitting his innovative proposal titled, "Development of a novel diagnostic test that can distinguish active infection with clostridium difficile from colonization.”


Following is a lay abstract from the pilot grant proposal:

Clostridiodes (Clostridium) difficile is a bacteria that can form dormant spores and persist in the intestinal tract indefinitely without causing disease. It can also become metabolically active and initiate a spectrum of diarrheal illness culminating in severe infection and death. High colonization rates in hospitalized patients (15-50%) renders the distinction between colonization and active infection particularly important and uniquely difficult. Currently available protein-based tests miss up to 40% of infected patients. In contrast, molecular tests targeting toxin DNA genes do not discriminate between dormant spores and active infection, resulting in high false positive rates, leading to the unnecessary treatment of colonized patients and failure to detect and treat the true cause of disease (ex. inflammatory bowel disease, other bacteria/viruses). We have developed a novel diagnostic test that combines the positive attributes of current methods into a single assay with significant potential to distinguish colonization from active infection better than current methods.  In this proposal, we seek to optimize this novel assay (AIM 1) and evaluate its potential to promote more accurate diagnosis of patients with active C. difficile infection (AIM 2.) The proposed studies have significant potential to revolutionize C. difficile diagnostics and ameliorate patient morbidity and mortality associated with false positive test results. The collaborations, samples, data, and skill sets supported in this proposal will position our lab well to compete for external funds seeking to commercialize this assay, evaluate its clinical utility in particularly vulnerable populations (cystic fibrosis, inflammatory bowel disease), and thoroughly characterize host and microbial factors regulating colonization and active infection.

Dr. Leal joined the Division of Laboratory Medicine in 2018 as an Assistant Professor, Assistant Director of Clinical Microbiology, and Associate Director of the UAB Mycoplasma Diagnostic Reference Laboratory. He completed his residency in clinical pathology at the University of North Carolina and his fellowship in microbiology at the Cleveland Clinic. He is board certified in clinical pathology and medical microbiology with a special interest in mycology, parasitology, mycoplasmology, and histopathologic identification of microorganisms. Leal serves on the CAP Clinical Pathology Education Committee and harbors a significant interest in medical education.

by Hannah Weems