Whole genome sequnecing and genomic characterization of Aeromonas veronii isolated from condemned Danish broilers in a slaughterhouse

Aeromonas veronii is not a pathogen associated with disease in chicken. However, it is considered an emerging pathogen within human health. In this study, a total number of 400 chicken carcasses were randomly collected from October 2020 to February 2021 from one of the largest chicken slaughterhouses in Denmark. These samples represent three condemnation conditions: cellulitis, scratches and hepatitis, and non-condemned healthy chicken carcasses as control. From every carcass, three samples were obtained: one from the lesion, one from the pectoral muscle and one from the bone marrow of the femur. All samples were cultivated using 5% blood agar, consisting of blood agar base (Oxide, United Kingdom) and sterile bovine blood. The plates were incubated at 37°C under aerobic conditions for 24 to 48 hours. Identification of bacterial species was done using MALDI-TOF MS. Aeromonas spp. were found in 27.9% of the carcasses. A. veronii was the most predominant species within the Aeromonas family. Whole genome sequnecing was performed using a standard protocol with Illumina MiSeq. We screened the sequenced isolates for virulence genes, antimicrobial resistance genes, plamsids, pro-phages and carried out a phylogenetic analysis.