Assessment of the best inoculation route for virulotypingEnterococcus cecorumstrains in a chicken embryo lethality assay

Characterizing the impact of Enterococcus cecorum infection during late embryogenesis on disease progression, cecal microbiome composition, and early performance in broiler chickens

“…However, pathogenicity should be confirmed by conducting in vivo studies. Embryo lethality assays ( ELA ) have been used to differentiate between commensal and pathogenic EC strains ( Borst et al, 2014 ; Jung and Rautenschlein, 2014 ; Dolka et al, 2022 ; Manders et al, 2022 ). The impact of embryonic exposure to EC on performance cannot be evaluated when using ELAs to assess pathogenicity since these experiments terminate during embryogenesis.…”

“…Phenotypic and genotypic analyses have been used to categorize and differentiate between commensal and pathogenic strains of EC ( Borst et al, 2015 ; Dolka et al, 2016 ; Borst et al, 2017 ; Jung et al, 2017 ). Virulence of EC strains has also been assessed in vivo with embryo lethality assays ( Borst et al, 2014 ; Jung et al, 2017 ; Ekeski et al, 2021 ; Dolka et al, 2022 ; Manders et al, 2022 ; Huang et al, 2023 ). Schreier et al (2021) demonstrated that an EC isolate that caused high embryonic mortality, and deemed to be pathogenic, did not induce disease when administered to chicks at hatch.…”