SPS22-18GL

Determining the main source of antibiotic-resistant infections through the diversity of Pathogenic Sequence Types

By: Lorena Benitez-Rivera, Candace Clark, and Anjani Pradhananga

Department: Cellular & Molecular Biology

Faculty Advisor: Dr. Pleuni Pennings 

The increasing number of antibiotic resistant infections is a global threat to human health. Antibiotic resistance is the inability of antibiotics to treat the infections that were once treatable. Antibiotic resistance is a defense mechanism for the survival of pathogens, and occurs due to genetic modifications. In order to fight these resistant infections, it is important to know their origin. The problem lies in the fact that in many cases, the origin of these resistant infections is unknown. Antibiotic resistance might have evolved within patients, or may have been transmitted between patients. We expect that in situations where transmission is important, the diversity of the resistant strains is lower than the diversity of the susceptible strains. Diversity is therefore key in finding the main origin of resistance. In this study we determined diversity for resistant and susceptible strains from published datasets. We performed a retrospective study of six datasets with sequence type data; we analyzed the data using the R programming language, and calculated Simpsons’s Index to measure diversity of susceptible and resistant strains. We used a bootstrapping approach to estimate significance. Our result suggests that diversity of the resistant strains is less than that of the susceptible population in some but not all of the cases. Thus, these studies of antibiotic resistance provide insight into how antibiotic resistance evolves and spreads, so that antibiotic resistance could be minimized.