The role of rpoS, hmp, and ssrAB in Salmonella enterica Gallinarum and evaluation of a triple-deletion mutant as a live vaccine candidate in Lohmann layer chickens.
10.4142/jvs.2015.16.2.187
- Author:
Youngjae CHO
1
;
Yoon Mee PARK
;
Abhijit Kashinath BARATE
;
So Yeon PARK
;
Hee Jeong PARK
;
Mi Rae LEE
;
Quang Lam TRUONG
;
Jang Won YOON
;
Iel Soo BANG
;
Tae Wook HAHN
Author Information
1. College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 200-701, Korea. twhahn@kangwon.ac.kr
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
live attenuated vaccine;
oxidant response genes;
protection;
Salmonella enterica Gallinarum;
virulence
- MeSH:
Administration, Oral;
Animals;
Bacterial Proteins/*genetics/immunology;
*Chickens;
Female;
Poultry Diseases/*immunology/microbiology;
Salmonella Infections, Animal/*immunology/microbiology;
Salmonella Vaccines/administration & dosage/genetics/*immunology;
Salmonella enterica/immunology/*physiology;
Vaccines, Attenuated/administration & dosage/genetics/immunology;
Virulence
- From:Journal of Veterinary Science
2015;16(2):187-194
- CountryRepublic of Korea
- Language:English
-
Abstract:
Salmonella enterica Gallinarum (SG) causes fowl typhoid (FT), a septicemic disease in avian species. We constructed deletion mutants lacking the stress sigma factor RpoS, the nitric oxide (NO)-detoxifying flavohemoglobin Hmp, and the SsrA/SsrB regulator to confirm the functions of these factors in SG. All gene products were fully functional in wild-type (WT) SG whereas mutants harboring single mutations or a combination of rpoS, hmp, and ssrAB mutations showed hypersusceptibility to H2O2, loss of NO metabolism, and absence of Salmonella pathogenicity island (SPI)-2 expression, respectively. A triple-deletion mutant, SGDelta3 (SGDeltarpoSDeltahmpDeltassrAB), was evaluated for attenuated virulence and protection efficacy in two-week-old Lohmann layer chickens. The SGDelta3 mutant did not cause any mortality after inoculation with either 1 x 10(6) or 1 x 10(8) colony-forming units (CFUs) of bacteria. Significantly lower numbers of salmonellae were recovered from the liver and spleen of chickens inoculated with the SGDelta3 mutant compared to chickens inoculated with WT SG. Vaccination with the SGDelta3 mutant conferred complete protection against challenge with virulent SG on the chickens comparable to the group vaccinated with a conventional vaccine strain, SG9R. Overall, these results indicate that SGDelta3 could be a promising candidate for a live Salmonella vaccine against FT.
