Andras Fodor
University of Pannonia, Hungary
Title: Agrobacterium: a Suitable Genetic System for Analysis Resistance to Xenorhabdus Antimicrobial Peptide Complexes Extremely Active in Food Spoilage (Zoonic) Bacteria
Biography
Biography: Andras Fodor
Abstract
The emergence of antibiotic resistance proves an increasing challenge n prevention and control in microbial (zoonic) pathogens in foods. The aim of this work is to establish a suitable experimental system for genetic analysis of antimicrobial peptide-resistance in a genetically well-characterized Gram-negative target, and found Agrobacterium tumefaciens. Intentionally, not a single but a multiple antimicrobial peptide-complex (EMA_PF2, isolated from Xenorhabdus budapestensis, with a reproducible MALDI profile), was chosen as a model to be bio-assayed in liquid cultures. Antimicrobial activity of EMA_PF2 is demonstrated on t Gram-positive Rhodococcus equi, Erysipelothrix rhusiopathiae, Staphylococcus aureus, Streptococcus equi, Corynebacterium pseudotuberculosis, and Listeria monocytogenes) and Gram negative Salmonella Gallinarum, Salmonella Derby, Bordetella bronchiseptica, Escherichia coli, Pasteurella multocida, Aeromonas hydrophila strains including multi-resistant ones. A. tumefaciens A281 strain with C58 chromosome (originated from a nopaline-catabolizing strain) and intact (transfer-DNA, T-DNA carrying) pTiBo542 plasmid (with agropine (L, L, -succinamopine) catabolizing genes) proved fully resistant to EMA_PF2; while the studied disarmed (transfer-DNA-deleted, del-T-DNA) plasmid-harboring derivatives (AGL1; EHA105 and A4T) were fully sensitive. By contrast, all 5 examined pTi58-plasmid-cured derivatives of C58 nopaline-catabolizing strains proved resistant to EMA_PF2. Two octopine-catabolizing strains behaved differently. Agrobacterium strains sensitive to EMA_PF2, harboring disarmed pTiBo542 provide a system for genetic complementation analysis of resistance to antimicrobial peptides using complementary sequences from resistant strains.