The Spread of Salmonella gallinarum 9R Vaccine Strain under Field Conditions

Feberwee, Anneke; Hartman, E.G.; Wit, Janneke; Vries, T. S. de

doi:10.2307/1592883

Cited by 27 publications

(9 citation statements)

References 9 publications

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“…5 %) [27]. In 4500 eggs derived from five S. Gallinarum 9R vaccinated flocks, no vaccine strain bacteria were detected, while no evidence was found in another study for the faecal spread of the vaccine strain [26,100].…”

Section: Vaccines and Adaptive Immunitymentioning

confidence: 84%

Vaccination and early protection against non-host-specific Salmonella serotypes in poultry: exploitation of innate immunity and microbial activity

et al. 2005

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A recent European Union Directive required member states to put monitoring and control programmes in place, of which vaccination is a central component. Live Salmonella vaccines generally confer better protection than killed vaccines, because the former stimulate both cell-mediated and humoral immunity. Administering Salmonella bacteria orally to newly hatched chickens results in extensive gut colonization and a strong adaptive immune stimulus but broiler chickens are immunologically immature. However, colonization exerts a variety of rapid (within 24 h) protective effects. These include specific colonization-inhibition (competitive exclusion) in which the protective bacteria exert a profound resistance to establishment and colonization by other related bacteria. This is thought to be primarily a metabolic attribute of the vaccinating bacteria but may also involve competition for attachment sites. The presence of large numbers of bacteria originating from a live Salmonella vaccine in the intestine can also induce infiltration of polymorphonuclear cells into the intestinal wall, which confers resistance to invasion and systemic spread by virulent Salmonella strains. This opens new perspectives for vaccine usage in broilers, layers and breeding poultry but also in other animals which show increased susceptibility to infection because of their young age or for other reasons, such as oral chemoprophylaxis or chemotherapy, where the lack of established normal gut flora is an issue. We recommend that all live vaccines considered for oral administration should be tested for their ability to induce the two protective effects described above. Further developments in live Salmonella vaccines are, however, currently hindered by fears associated with the use and release of live vaccines which may be genetically modified.

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Section: Vaccines and Adaptive Immunitymentioning

confidence: 84%

Vaccination and early protection against non-host-specific Salmonella serotypes in poultry: exploitation of innate immunity and microbial activity

et al. 2005

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“…This theory was confirmed in a large field trial in the Netherlands in which 80 commercial flocks were vaccinated with the SG9R vaccine strain and the flock level of occurrence of SE infections was 2.5% (2/80 flocks), which was significantly less than that in unvaccinated flocks (214 out of 1854 flocks, 11.5%; Feberwee et al, 2001a). No vaccine strain bacteria were detected in 4500 eggs derived from five SG9R vaccinated flocks, while in another study no evidence was found for the faecal spread of the vaccine strain (Feberwee et al, 2000(Feberwee et al, , 2001b.…”

Section: Discussionmentioning

confidence: 87%

Efficacy of several vaccination programmes in commercial layer and broiler breeder hens against experimental challenge withSalmonella entericaserovar Enteritidis

et al. 2009

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“…The infections by SG are usually acute, and the spread of the bacteria is more intense if carcasses of infected dead chickens are exposed to other chickens (BARROW et al, 1994;BERCHIERI JR. et al, 2000). SG can survive in the animal environment, and, due to the constant and slow horizontal transmission, the mortality is persistent in affected flocks, making it difficult to eradicate the infection (FEBERWEE et al, 2001b).…”

Section: Palavras-chavementioning

confidence: 99%

Protection of chickens against fowl typhoid using field vaccine programs formulated with the live attenuated strain Salmonella Gallinarum ΔcobSΔcbiA

et al. 2018

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Salmonella enterica serovar Gallinarum biovar Gallinarum (SG) is a host-specific bacteria that causes the fowl typhoid (FT). This disease is highly pathogenic to commercial chickens, specially brown layers and breeders, causing acute septicemia followed by high morbidity and mortality. Vaccination is extensively adopted in the fields as a biosafety tool for prevention of isolated infections and outbreaks in commercial poultry flocks. The present study evaluated the use of an attenuated SG with deletions on genes cobS and cbiA (SGΔcobSΔcbiA) as a live vaccine, using vaccination schemes adjusted for field conditions. To this end, brown layers were used in two different experiments, to evaluate the long-term protection, necessary in the fields. The vaccination scheme on the first experiment consisted of two doses, the first at 4 th week-of-age and the booster dose at 8 th week-of-age with challenge at 16 th week-of-age with wild SG strain. On the second experiment, the vaccination was carried out by different routes using three doses of the live vaccine, at 4 th , 8 th and 12 th weeks-of-age, and the challenge was done at 20 th weeks-of-age. After the challenge, the mortality was recorded during 28 days, and the egg production (experiment 2) was evaluated and compared with the group of unvaccinated layers. In both experiments, the mortality was significantly reduced, and the egg production was not affected in vaccinated layer-hens. In summary, this study shows the efficacy and the protection of different vaccination schemes against FT that can be applied under field conditions in commercial poultry farms.

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The Spread of Salmonella gallinarum 9R Vaccine Strain under Field Conditions

Cited by 27 publications

References 9 publications

Vaccination and early protection against non-host-specific Salmonella serotypes in poultry: exploitation of innate immunity and microbial activity

Vaccination and early protection against non-host-specific Salmonella serotypes in poultry: exploitation of innate immunity and microbial activity

Efficacy of several vaccination programmes in commercial layer and broiler breeder hens against experimental challenge withSalmonella entericaserovar Enteritidis

Protection of chickens against fowl typhoid using field vaccine programs formulated with the live attenuated strain Salmonella Gallinarum ΔcobSΔcbiA

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