Reduction ofSalmonellaEnteritidis in the Spleens of Hens by Bacterins That Vary in Fimbrial Protein SefD

Abstract

The objective of this research was to determine whether variation in the presence of fimbrial protein SefD would impact efficacy of bacterins as measured by recovery of Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) from the spleens of hens. Two bacterins were prepared that varied in SefD content. Also, two adjuvants were tested, namely, water-in-oil and aluminum hydroxide gel (alum). Control groups for both adjuvant preparations included infected nonvaccinated hens and uninfected nonvaccinated hens. At 21 days postinfection, Salmonella Enteritidis was recovered from 69.7%, 53.1%, and 86.0% from the spleens of all hens vaccinated with bacterins lacking SefD, bacterins that included SefD, and infected nonvaccinated control hens, respectively. No Salmonella was recovered from uninfected nonvaccinates. Results from individual trials showed that both bacterins reduced positive spleens, but that the one with SefD was more efficacious. Alum adjuvant had fewer side effects on hens and egg production as compared to water-in-oil. However, adjuvant did not change the relative recovery of Salmonella Enteritidis from spleens. These results suggest that SefD is a promising target antigen for improving the efficacy of immunotherapy in hens, and is intended to reduce Salmonella Enteritidis in the food supply.

Serotyping of <i>Salmonella Enterica</i> Isolated from Mice Caught on US Poultry Farms 1995 through 1998

“…For example, farms experiencing a sudden increase in mouse populations could pursue serotyping of Salmonella of mice to evaluate vaccination strategies for reducing colonization of poultry. Whole-genome analysis will be required to determine detailed genome content of serotypes and to provide further information for assessing evolutionary trends and for selecting vaccine strains 20) . Sequencing and assembly of isolates are in progress with 64 isolates of serotype Enteritidis from this study currently available as unassembled reference sequences 21) .…”

Salmonella Fimbriae: What is the Clue to Their Hairdo?

“…SefD, another antigen from SEF14, was also used to vaccinate animals in a bacterin preparation, a vaccine prepared from inactivated bacteria. This vaccine was efficient to reduce the presence of Salmonella from the spleens of hens [90].…”

AT Homopolymer Strings in Salmonella enterica Subspecies I Contribute to Speciation and Serovar Diversity

“…Mutational analysis, phenotype microarray, and infection experiments in the egg-laying hen indicated that the sefD mutation increased organ invasion and mortality in hens, disturbed egg production, enhanced growth of the pathogen to high cell density, and otherwise behaved as a regulator of dimorphism of phenotype [4]. As a result of this finding the performance of a killed vaccine for hens was enhanced by increasing SefD in preparations [5]. The drastic change in biological phenotype imparted by the single base pair deletion suggested that characterization of purine homopolymer strings of adenine, AAAAAAAA, and its pyrimidine base pair (bp) of thymine, TTTTTTTT, in S. enterica should be explored.…”