SEF14 fimbriae from Salmonella enteritidis play a role in pathogenitic to cell model in vitro and host in vivo

• sefA mutant constructed in the wild-type (WT) Salmonella enteritidis strain 50336.
• sefA mutant strain displayed increased invasion to IPEC-J2 cell lines.
• sefA mutant strain displayed increased survival in mouse peritoneal macrophage.
• sefA mutant strain displayed increased virulence to 6-week-old Balb/c mice.

The role of SEF14 fimbriae in virulence remains to be elucidated and in this study, we showed that sefA mutant constructed in the wild-type (WT) Salmonella enteritidis strain 50336 displayed increased invasion to IPEC-J2 cell lines and survival in mouse peritoneal macrophages, and the lethal dose 50% (LD50) in 6-week-old Balb/c mice intra-peritoneally injected with WT S. enteritidis strain decreased significantly upon deletion of sefA indicating their role in virulence. Overall, these results demonstrated that expression of sefA of SEF14 fimbriae enhances S. enteritidis adhesion to epithelial cells and survival in macrophages and contributes to S. enteritidis virulence in mice.