Use of life and inactivated Salmonella enteriditid=s phage type 4 vaccines to immunise laying hens against experimental infection

Abstract

Four groups of Dekalb Delta commercial layer hens (8 hens per group) were reared individually in cages in an isolation unit. At the age of 8 weeks, groups 1 and 2 were vaccinated with 9R Salmonella gallinarum live (9R live) vaccine. At the age of 18 weeks, group 1 was re-vaccinated with 9R live S. enteritidis vaccine, while groups 2 and 3 were vaccinated with S. enteritidis bacterin. At the age of 22 weeks, groups 2 and 3 were re-vaccinated with S. enteritidis bacterin. Group 4 was not vaccinated and was kept as a control group. At 24, 27 and 30 weeks of age, the four groups were challenged using various concentrations of S. enteritidis phage type 4 and various routes of inoculation. Eggs, cloacal swabs and blood were collected weekly for bacteriological and serological examination. Isolation of the challenge organism from the eggshells and egg contents of the vaccinated groups was significantly lower than with the control group. There was no correlation between humoral antibodies and the shedding of the challenge organism in eggs or cloacal swabs.A combined vaccination programme of 9R live S. enteritidis vaccine and S. enteritidis bacterin provided better protection to laying hens than either vaccine administered alone. Vaccination should never be performed alone but in conjunction with other measures related to veterinary hygiene and good management.

Protection AgainstSalmonellaTyphimurium,SalmonellaGallinarum, andSalmonellaEnteritidis Infection in Layer Chickens Conferred by a Live AttenuatedSalmonellaTyphimurium Strain

“…In one study, an attenuated ST vaccine strain was shown to offer protection against SE virulent challenge in chickens ( 31 ). One report also demonstrated the protection efficacy of SG vaccines against virulent SE infections in laying hens ( 32 , 33 ). In our previous studies, we constructed a live attenuated ST strain ( 34 ).…”

“…In our previous studies, we constructed a live attenuated ST strain ( 34 ). As several other studies previously explored the cross-protection conferred by Salmonella vaccines against related serovars ( 31 , 32 , 33 , 35 ), immunization with this ST strain may confer protection against salmonellosis.…”

Efficacy of bacterin-, outer membrane protein- and fimbriae extract-based vaccines for the control of Salmonella Enteritidis experimental infection in chickens

“…Different types of salmonella vaccines have been used in chickens to immunize and protect against excretion of salmonella; however, complete protection against the elimination of highly infectious serotypes immediately after challenge has not yet been achieved (Nassar et al 1994, Freitas Neto et al 2008, Atterbury et al 2009, Revolledo & Ferreira 2010.…”

Efficacy for a New Live Attenuated Salmonella Enteritidis Vaccine Candidate to Reduce Internal Egg Contamination

“…However, the efficacy of live vaccines is variable and not always satisfactory because residual virulence may remain that requires host clearance (Matsui et al., ; Takaya et al., ; Singh, ). The efficacy of live vaccines in poultry has been examined in experimental and field studies, but to our knowledge, only a few studies have shown improvements in the protective effect of immunization against egg contamination (Nassar et al., ; Hassan and Curtiss, ; Gantois et al., ).…”