Development and evaluation of an experimental vaccination program using a live avirulent Salmonella typhimurium strain to protect immunized chickens against challenge with homologous and heterologous Salmonella serotypes

Abstract

A stable live avirulent, genetically modified Acya Acrp SalmoneUla typhimurium vaccine strain, x3985, was used in several vaccination strategies to evaluate its use in the control of SalmoneUla infection in chickens. Oral vaccination of chickens at 1 and at 14 days of age with 108 CFU of x3985 protected against invasion of spleen, ovary, and bursa of Fabricius and colonization of the ileum and cecum in chickens challenged with 106 CFU of virulent homologous SalmoneUla strains from group B. Chickens challenged with heterologous Salmonella strains from groups C, D, and E were protected against visceral invasion of spleen and ovary, while invasion of the bursa of Fabricius and colonization of ileum and cecum was reduced in vaccinated chickens. Oral vaccination at 2 and at 4 weeks of age induced an excellent protection against challenge with virulent group B Salmonella serotypes and very good protection against challenge with group D or E SalmoneUla serotypes, while protection against challenge with group C SalmoneUa serotypes was marginal but significant. Vaccination at 2 and at 4 weeks of age also protected vaccinated chickens against challenge with 108 CFU of highly invasive S. typhimurium or S. enteritidis strains. The protection of chickens vaccinated with X3985 against challenge with homologous and heterologous Salmonella serotypes is outstanding, and the complete protection against ovarian

The Simultaneous Administration of a Probiotic or Prebiotic with Live Salmonella Vaccine Improves Growth Performance and Reduces Fecal Shedding of the Bacterium in Salmonella-Challenged Broilers

“…Positive control birds had the highest mortality rate, which was 25% (6/24 birds), although the same dose of SE resulted in 30.67% deaths on positive control birds by Abd El-Ghany et al [28], who performed the infection at 20 days of age. The difference of challenging age may be the cause of the different results, as the susceptibility of chickens to infection with Salmonella is age-dependent [29] and the chicken breed used may also play a role.…”

The chicken, the egg and Salmonella enteritidis

“…2). Investigation of interactions between Salmonella serotypes confirmed that competitive exclusion between avian-adapted serotypes and S. enteritidis is possible and that, sometimes, cross-protection can be demonstrated, as observed between S. enteritidis and other Salmonella serotypes (Schlecht, 1981;Hassan and Curtiss, 1994;1997;Tabaraie et al, 1994;Hormaeche et al, 1996;Rabsch et al, 2000;Nicholson and Baumler, 2001). Further investigation may provide additional evidence that there is some special aspect to interactions between S. enteritidis and the Eggs are said to be contaminated rather than infected, as they are not fertile and do not contain living cells.…”

Virulence and vaccine potential ofSalmonella typhlmuriummutants deficient in the expression of the RpoS (σs) regulon

“…These strains cause an invasive infection in susceptible mice that resembles typhoid in humans. Attempts have also been made to develop live Salmonella vaccines for agriculturally important animals such as chicken, calves, swine and sheep (Robertsson et a/., 1983;Smith et a/., 1984;Cooper et al, 1990;Jones et a/., 1991;Hassan and Curtiss, 1994;Brennan et a/., 1994;Roof and Doitchinoff, 1995). The protection of livestock against diarrhoea1 and systemic disease is potentially of economic importance in farming and animal husbandry.…”