Efficacy of several Salmonella vaccination programs against experimental challenge with Salmonella gallinarum in commercial brown layer and broiler breeder hens

Abstract

The protective effect of various Salmonella vaccines regimens against an experimental Salmonella Gallinarum challenge (SGNalr strain at 12 wk of age) was evaluated in two experiments. In Experiment 1 commercial brown layers were vaccinated according to one of the following programs: (i) two doses of a SE bacterin (Layermune SE; group 1); (ii) a first dose of a live SG9R vaccine (Cevac SG9R) followed by a SE bacterin (Layermune SE; group 2); (iii) one dose of each of two different multivalent inactivated vaccines containing SE cells (Corymune 4 & Corymune 7; group 3) or (iv) not vaccinated (group 4). In Experiment 2, broiler breeders were given the same vaccination treatments except for the group vaccinated with the multivalent vaccines. Overall, in both experiments, all vaccination schemes were effective in reducing mortality after challenge with a SG field strain. Primary vaccination with an initial dose of a live SG9R vaccine followed some weeks later by a dose of an inactivated SE bacterin was the most effective (p<0.05) vaccination program against mortality induced by field SG experimental challenge in both experiments. In conclusion, Salmonella vaccination programs containing SE bacterins alone or in combination with a live SG9R vaccine are effective in preventing mortality induced by infection of field SG. Nevertheless, it is important to emphasize that any vaccination program against any Salmonella serotype will only be effective if it is part of a sound and comprehensive biosecurity program designed for Salmonella control in poultry farms

Determination of egg production and weight in layers experimentally infected with Salmonella gallinarum

“…The clinical signs observed in the S. gallinarum-infected layers in this study, which included depression, ruffled feathers, huddling, loss of body weight, drop in egg production, somnolence and greenish-yellow diarrhoea were consistent with findings in previous reports (Shivaprasad, 2000;Freitas Neto et al, 2007;Ezema et al, 2009;Garcia et al, 2010). The 50% mortality in the layers recorded in this study was in the range (10 to 100%) reported previously (Shivaprasad, 1996;Uzzau et al, 2000;Oliveira et al, 2005;Paiva et al, 2009) in chickens. A significant (P<0.05) progressive drop in egg production was observed in the infected layers from 1 th week pi and reaching its maximum drop on the 4 th week pi.…”

Salmonella Gallinarum virulence in experimentally-infected Japanese quails (Coturnix japonica)

“…This result was expected, because scientific literature mentions that SG produces a severe disease, with significant mortality rates in chickens (Compra et al, 2008). Mortality caused by SG may be higher than 80% in broilers (Paiva et al 2009), and may reach almost 100% in inoculated young brown layers (Oliveira et al, 2005). Accordingly, 94.7% mortality was recorded in G3 in the present experiment.…”

Prevalence and epidemiology of Salmonella enterica serovar Gallinarum from poultry in some parts of Haryana, India

“…Control of FT is difficult due to the endemicity of the disease [13], facultative intracellular nature of the organism, both vertical [14] and horizontal [15] modes of transmission, multiple drug resistance and presence of carrier stage. The indiscriminate and widespread use of antibiotics in the treatment of poultry diseases has lead to increase in the number of resistant Salmonella strains isolated [16].…”