Influence of management practices on virulence factors, antimicrobial resistance genes and heavy metal resistance genes in broiler chicken production
Date
2023
Authors
Woyda, Reed Richard, author
Abdo, Zaid, advisor
Oladeinde, Adelumola, committee member
Daniels, Josh, committee member
Sloan, Dan, committee member
Stenglein, Mark, committee member
Journal Title
Journal ISSN
Volume Title
Abstract
The main bacterial species associated with food-borne illness in humans are Escherichia coli, Salmonella species and Campylobacter species. The ability of a bacterial strain to survive the food-production pipeline and to mount an infection and cause disease in humans is dependent on an array of genetic factors. The presence of specific virulence factors will influence the severity of disease while antimicrobial resistance genes affect the choice and efficacy of treatment. Management practices in poultry production aim at reducing the incidence of poultry and human bacterial pathogens and, in general, at maintaining a healthy flock and a healthy global population. However, the influence of management practices, in a post-antibiotic era, on pathogenic bacterial species, and in particular the selective pressures imposed on genetic factors such as antimicrobial and metal resistance and virulence factors, are understudied. In Chapter 2, we provide a robust bacterial genomic analysis pipeline which is used for subsequent analysis in the following chapters. Chapter 3 provides an understanding of the current antimicrobial resistance and virulence factors present in chicken production and human clinical settings. This work found these host sources harbored different antimicrobial resistance genes and virulence factors that can classify them into phylogroups and host origin. In Chapter 4, through characterization of Campylobacter species isolated from broiler litter, we determined the reused litter environment selected for Campylobacter species lacking virulence factors aiding in colonization of chicken and human hosts. In Chapter 5, we determined the practice of adding copper sulfate to drinking water, commonly used for growth promotion or sanitization, may have selected for, and provided a reservoir for, Salmonella strains harboring plasmid-borne copper resistance genes. Overall, this work provides a computational pipeline for the high-throughput analysis of bacterial genomes and provides insights into selective pressures imposed on pathogenic bacterial species by modern-day management practices.
Description
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