Exploring a Pathogenomic Approach and the Galleria mellonella Model to Evaluate the Virulence of Arcobacter butzleri.

Arcobacter butzleri is an emerging zoonotic pathogen described in 1991. Despite its increasing incidence in clinical cases, there is still a need to better understand the underlying mechanisms of pathogenicity. Therefore, the aim of this study was to evaluate if different virulence profiles of A. butzleri are associated with different extent of virulence in the Galleria mellonella experimental model. Twenty-one A. butzleri strains isolated from various sources were characterized by searching for putative virulence determinants (PVDs) through genomic analysis and PCR (i.e., cadF, cj1349, ciaB, mviN, tlyA, pldA, irgA, hecA, hecB, and iroE genes). Seven virulence profiles were obtained (designated as Profile A to G). A representative strain from each profile was selected to conduct assays in the G. mellonella model. Even though the profile C was the most virulent, there was no correlation between the virulence profiles and G. mellonella mortality/melanization. Our study show that G. mellonella is a reliable and cost-effective model for studying the pathogenicity of A. butzleri. However, our results underscore the significance of evaluate additional virulence factors beyond the analyzed PVDs.