The host model Galleria mellonella is resistant to taylorellae infection

Abstract

The genus Taylorella is composed of two species: (i) Taylorella equigenitalis, the causative agent of CEM, a venereally transmitted infection of Equidae and (ii) Taylorella asinigenitalis, a closely related species considered to be nonpathogenic, although experimental infection of mares with this bacterium resulted in clinical signs of vaginitis, cervicitis or endometritis. Currently, there is a need for an alternative host model to further study the taylorellae species. In this context, we explored Galleria mellonella larvae as potential alternative model hosts for taylorellae. Our results showed that infection of G. mellonella larvae with a high concentration of taylorellae did not induce overt G. mellonella mortality and that taylorellae were not able to proliferate within G. mellonella. In conclusion, G. mellonella larvae are resistant to taylorellae infection and therefore do not constitute a relevant alternative system for studying the virulence of taylorellae species. Significance and impact of the study: To date, the pathogenicity and host colonization capacity of Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM) and T. asinigenitalis, the second species within the Taylorella genus, remain largely unknown. In this study, we evaluated the relevance of Galleria mellonella as an infection model for taylorellae; we showed that G. mellonella are resistant to taylorellae infection and therefore do not constitute a suitable host model for taylorellae.

Establishing Galleria mellonella as an invertebrate model for the emerging multi-host pathogen Helcococcus ovis

“…In this study, we showed that H. ovis isolated from the uterus of dairy cows can establish an active infection in G. mellonella larvae. A previous attempt at establishing a G. mellonella infection model for a metritis-causing pathogen of horses, Taylorella equigenitalis (T. equigenitalis) , found the bacterium was unable to replicate within this model host [ 17 ]. Therefore, the first step in establishing this model was to measure the ability of H. ovis to replicate within the larvae and cause disease.…”