Physical Sciences and Mathematics Commons^™

Clostridioides Difficile Biofilm And Spore Production In Response To Antibiotics And Immune Stress, Adenrele M. Oludiran

Chemistry & Biochemistry Theses & Dissertations

The development of new therapeutic options against Clostridioides difficile (C. difficile) infection is a critical public health concern, as the causative bacterium is highly resistant to multiple classes of antibiotics. C. difficile, an anaerobic spore-forming Gram-positive pathogenic bacterium, is a major cause of hospital-acquired infections. C. difficile persists in the environment and spreads the infection to new hosts in the form of dormant spores and can persist within hosts as surface-attached biofilms. These studies investigate bacterial vegetative cell survival, biofilm formation, and sporulation in response to stress. Antimicrobial host-defense peptides (HDPs) are highly effective at simultaneously modulating …

Plastics And Microplastics As Vectors For Bacteria And Human Pathogens, Amanda Lee Laverty

OES Theses and Dissertations

Since plastics degrade very slowly, they remain in the environment on much longer timescales than most natural substrates and can thus provide a novel habitat for colonization by bacterial communities. The full spectrum of relationships between plastics and bacteria, however, is little understood. The objective of this study was to examine marine plastic pollution as a substrate for bacteria, with particular focus on Vibrio spp., including the human pathogens, Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus.

Colonization experiments were set up in a tributary of the lower Chesapeake Bay to follow Vibrio spp. colonization and …

Characterizing The Activity Of Antimicrobial Peptides Against The Pathogenic Bacterium Clostridium Difficile In An Anaerobic Environment, Adenrele Mojeed Oludiran

Chemistry & Biochemistry Theses & Dissertations

Clostridium difficile is an anaerobic Gram-positive pathogen with high treatment costs and mortality and very high antibiotic tolerance. Antimicrobial host-defense peptides (HDPs) produced naturally by animal immune systems are promising candidates to develop novel therapies for bacterial infection because they cause oxidative stress that damages multiple targets in bacterial cells, so it is difficult for bacteria to evolve resistance to these attacks.

Piscidins, fish-derived HDPs that can also form complexes with copper (Cu) to enhance their activities, are very active against multiple bacterial species in an aerobic environment. We examined their activity against C. difficile and other species in an …