Aims: The study aimed to investigate the prevalence and conservation of endocarditis and biofilm-associated pili (ebp) genes in Enterococcus faecalis originated from animals and the potential of developing Ebp into serological diagnostic and vaccine targets.
Methods and results: In this work, we investigated the prevalence and conservation of ebp genes in 116 strains of E. faecalis originated from animals by using PCR and sequencing methods. The results demonstrated the presence of ebp genes (ebpA, ebpB and ebpC) in all 116 strains of E. faecalis, and their amino acid homology ranges from 96.6% to 100.0%. Moreover, the phylogenetic analysis of ebp genes in all 164 E. faecalis strains (including 48 reference strains) revealed that ebp genes show no significant correlation with species origins and regions of E. faecalis, indicating that ebp genes are conserved features in E. faecalis, even though it evolved under environmental pressures from various regions and origins. Given that EbpA1 as a part of the adhesion protein EbpA has immunogenicity, we further determined whether amino acid mutations have effects on the function and 3D structure of EbpA1. The results showed that two of the 26 mutations, at amino acids positions 178 and 387, had deleterious effects on the biological function of EbpA1 protein, while all mutations had no effect on the 3D structure or binding pockets of EbpA1 protein.
Conclusions: This study suggests that ebp genes are prevalent and conserved in E. faecalis originated from diverse animal origins and regions. EbpA1 could be a potential target for serological diagnosis and vaccine development to prevent E. faecalis infection.
Significance and impact of study: The current study provides data to support further research on Ebp as a serological diagnostic and vaccine target against E. faecalis infection.
Keywords: Enterococcus faecalis; EbpA1 protein; ebp gene; serological diagnosis; vaccine target.
© 2021 The Society for Applied Microbiology.