PhD Oral Defence of Anna Colavecchio, Food Science and Agricultural Chemistry
Each year, approximately 700,000 deaths worldwide are attributed to antibiotic resistance (AR), and this number is predicted to rise to 10 million by 2050. Antibiotic resistance genes (ARGs) can be found on mobile genetic elements (MGEs), including a novel MGE, termed phage-like plasmid (PLP), which is a phage/plasmid hybrid that exists extrachromosomally within bacterial cells. The objective of this study was to develop a better understanding of PLP genomic structure and biology, by focusing on two main objectives: First, the genomic characterization of PLPs to determine their taxonomic structure and the types of ARGs and HMR genes that they carry. Second, phenotypic analysis of the potential of PLPs to horizontally transfer ARGs and HMR genes by phage-mediated mechanisms, such as transduction, or plasmid-mediated mechanisms, such as transformation and conjugation, in order to determine whether they can confer resistance to antibiotics and heavy metals.