Prevalence, Characterization, and Proteomic Relatedness Among β-Lactam-Resistant Bacteria Throughout the Poultry Production Chain in Greece.

Extended-spectrum-β-lactamase (ESBL) and carbapenemase-producing , and spp. are associated with hospital-acquired infections and are commonly isolated across the poultry food production chain. Comprehensive data regarding the prevalence, spatiotemporal variations, and characterization of β-lactam-resistant bacteria in poultry farms and slaughterhouses is scarce. This study examines the prevalence and characteristics of β-lactam-resistant , , and spp. isolated from poultry farms, slaughterhouses, and associated personnel in Greece. Strains were selectively isolated and identified via MALDI-TOF MS, which was also employed to identify possible relatedness. isolates were further classified into phylogenetic groups. The prevalence of β-lactam-resistant strains in farm and slaughterhouse environments was 15.0% (n = 15 strains)/57.3% (n = 71 strains) for , 11.0% (n = 11 strains)/1.6% (n = 2 strains) for , and 1.0% (n = 1 strain)/25.8% (n = 38 strains) for spp., respectively. The prevalence of spp. and on farmers' skin was 16.7% (n = 2 strains) and 8.3% (n = 1 strain), correspondingly. Significantly higher isolation rates were observed in warmer seasons. All strains were multidrug-resistant and most carried ESBL/AmpC genes. Most isolates belonged to phylogroups A (41.4%, n = 36) and B1 (24.1%, n = 21). Proteomic analysis indicated relatedness among strains from different regions and seasons. Thus, poultry farms and slaughterhouses may serve as significant reservoirs of β-lactam-resistant strains of , , and spp.