Oral communication in One Health EJP Annual Scientific Meeting

June 9^th, 2021

Bernabé Diéguez B., Samper-Cativiela C., Ugarte-Ruiz M., de Frutos C., Duran M., Aguero M., Moreno MA. and Alvarez J.

Aim: Horizontal transfer, often involving plasmids, is a major mechanism of antimicrobial resistance (AMR) transmission [1]. Interestingly, S. Enteritidis, the most frequent serotype in animal and human sources in the European Union [2], is not typically associated with multidrug resistance phenotypes [3], what could be linked with different dynamics regarding plasmid uptake. The purpose of this study was to characterize plasmids circulating in S. Enteritidis strains from multiple sources and locations in Spain.
Methods: Overall, 179 S. Enteritidis isolates retrieved in 2004-2019 from several sources (domestic and wild animals, food and environment) were sequenced with Illumina technology. Spades was used for genome assembling. AMR genes and plasmid
replicons were identified with ResFinder and PlasmidFinder, respectively. Plasmids sequences were built with Recycler and compared with Blast. Roary was used for pangenome analysis.
Results: IncX1 replicons were identified in 27/179 strains but the plasmid sequence of 22 could be obtained. 5 putative IncX1 plasmid groups (plasmids sharing the same genes and highly similar sequences) were identified in more than one strain, two of
which were associated with resistance genes: group 1 carrying aadA1, sul1, tet(A) and dfrA1 in 4 laying hens strains from two distant Spanish regions and time periods (2008-2018); and group 2 carrying a blaTEM-1B gene found in strains from egg and
laying hen samples collected 10 years apart.
Conclusions: Our comparative genomic analysis revealed the existence of similar plasmids in epidemiologically unrelated S. Enteritidis strains present in animals and food in Spain, suggesting their sustained circulation although at relatively low levels

	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).
	Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM).