Oral communication in 17th International Symposium of Veterinary Epidemiology and Economics (ISVEE 17)

November 14^th, 2024

Alvarez J., Torre-Fuentes L., del Corral I., Lopez G., Sotodosos M., Perez I., Collado S., Sanchez E., de Frutos C., Rivero E., Maasoumi N., Aguero M., Saez JL. and Ugarte-Ruiz M.

Extended-spectrum beta-lactamase/plasmid-mediated AmpC beta-lactamase producing Escherichia coli (ESBL/pAmpC-EC) is a key indicator of the antimicrobial resistance (AMR) situation in animals and humans. For this reason, ESBL/pAmpC-EC is typically included in AMR surveillance programs, yielding useful data on its distribution in livestock and food products that could act as sources of infection for the general population. This information can be however limited if it is only based on the phenotypic characterization of ESBL/pAmpCEC resistance since multiple genes can confer a ESBL/pAmpC-EC resistance phenotype, and these can be found in different locations in the bacterial DNA suggesting diverse transmission dynamics. We analyzed data on the phenotypic characteristics of >2,500 ESBL/pAmpC-EC retrieved through the National AMR monitoring program in livestock (broiler, turkey, cattle, pig) and food over the 2014-2021 period to identify the main resistance profiles per host and over time in Spain. A subset of 113 isolates selected based on their characteristics were subjected to whole-genome sequencing (WGS) to assess their main resistance genes, their genetic diversity and the carriage of additional determinants. Most of the ESBL/pAmpC-EC isolates (85.9%) showed a classical ESBL phenotype, with 9.25%, 4.42% and 0.42% characterized as having AmpC, ESBL-AmpC or other resistance phenotypes. Furthermore, >50% of the ESBL/pAmpC-EC were resistant to tetracyclines, sulfonamides and fluoroquinolones irrespective of their origin. Still, multivariate techniques suggested an association between host and resistotype. ST10 and ST410 were the predominant sequence-types among sequenced isolates although a large genetic variability was found. Nevertheless, different predominant ESBL-encoding genes were found in poultry (blaSHV-12) versus cattle/pigs (blaCTX-M-15) although the most abundant plasmid groups (IncI, IncFIB ) were found across all host species. Our results demonstrate that predominant ESBL/pAmpC-EC differ per livestock species and that these may not always be found in related food products, suggesting complex dissemination dynamics across the food chain confirmed through WGS

	Servicio de Zoonosis de Transmisión Alimentaria y Resistencia a Antimicrobianos (ZTA). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).
	Laboratorio Central de Veterinaria (LCV). Ministerio de Agricultura, Pesca y Alimentación (MAPA).