Pathogenic role of SEF14, SEF17, and SEF21 fimbriae in Salmonella entericaserovar enteritidis infection of chickens

Very little is known about the contribution of surface appendages of Salmon ella enterica serovar Enteritidis to pathogenesis in chickens. This study w as designed to clarify the role of SEF14, SEF17, and SEF21 fimbriae in sero var Enteritidis pathogenesis. Stable, single, defined sefA (SEF14), agfA (S EF17), and fimA (SEF21) insertionally inactivated fimbrial gene mutants of serovar Enteritidis were constructed, All mutant strains invaded Caco-2 and HT-29 enterocytes at levels similar to that of the wild type. Both mutant and wild-type strains were ingested equally well by chicken macrophage cell lines HD11 and MQ-NCSU. There were no significant differences in the abili ties of these strains to colonize chicken ceca. The SEF14(-) strain was iso lated in lower numbers from the livers of infected chickens and was cleared from the spleens faster than other strains. No significant differences in fecal shedding of these strains were observed.