Emerging Variants of the Integrative and Conjugant Element ICEMh1 in Livestock Pathogens: Structural Insights, Potential Host Range, and Implications for Bacterial Fitness and Antimicrobial Therapy.

摘要: Horizontal gene transfer of integrative and conjugative elements (ICE) in bacterial pathogens the bovine respiratory disease (BRD) complex has emerged as a significant cause antimicrobial resistance (AMR) therapeutic failure mortalities cattle. The aim this study was to assess an AMR ICE occurring Pasteurella multocida from case BRD, designated ICEMh1PM22 for its structure host genome insertion site, identify consequences fitness therapy. modular ICEMh1-like found several related livestock compared ICEMh1PM22, repertoire cargo genes variable modules functionally categorized. were identified frequent additions elements. Random PCR-based mapping ICEMh1PM22-genome junctions transconjugants provided evidence that integrates into tRNA-leu UUG codon, not other codons. This separately confirmed genomes ICEMh1-like-harboring pathogens. Bacterial genera harboring receptive tRNA-leuUUG establish potential range ICEMh1PM22-carrying P. Mannheimia haemolytica less fit than isogenic strains without when grown selection. cost abrogated presence subinhibitory concentrations antimicrobials. Despite cost, retained extended culture. To possible efficiencies, combinations screened synergistic interactions against transconjugants. No combination tested exhibited or M. ICEMh1PM22. In conclusion, information on structural variation elements, refined site range, demonstrated risk following horizontal BRD