Immunizing efficacy of aromatic-dependent Salmonella dublin in mice and calves

Cross-protection of Salmonella abortusovis, S. choleraesuis, S. dublin and S. gallinarum in mice induced by S. abortusovis and S. gallinarum: bacteriology and humoral immune response

“…In a murine model, anti-lipid A monoclonal [7] or anti-idiotype antibodies [13] protected mice against a lethal challenge with rough LPS. However, it was demonstrated that by using direct passive transfer of anti-LPS antibodies [20,21,28,29,37], LPS alone cannot fully account for the specificity of protection by antibodies. The specificity of cross-protection was previously studied [19], using Typhimurium, Enteritidis and Dublin for vaccination and challenge, with variants that differed in the main LPS antigen (0-4 or 0-9).…”

Intramuscular vaccination of young calves with aSalmonellaDublin metabolic-drift mutant provides superior protection to oral delivery

“…Potential contamination of the environment through faecal shedding of vaccine organisms following oral vaccination, however, is a common problem, particularly when GMO are used as vaccine strains [28,29,40]. In this study, administration with N-RM25 via the IM route was more advantageous than via the oral route because of reduced shedding of the vaccine strain in faeces.…”

“…Some live vaccine candidates, such as aromaticdependent (aro − ) mutants [29,40] and DNA adenine methylase (Dam) deficient mutants [12,28] of Salmonella, have shown promise in preventing both homologous and heterologous Salmonella infection when orally administered to calves. However, while advanced oral delivery methods, such as encapsulation in microparticles have been developed [7,14], most live attenuated Salmonella vaccines administered to ruminants by this route can still potentially contaminate the environment due to regurgitation [10] and/or faecal shedding [29,40]. Furthermore, because these vaccine strains are genetically modified organisms (GMO), their use in animal production is not permitted in certain countries due to public health concerns [51].…”

Modulation of immune response in mice immunised with an inactivated Salmonella vaccine and gavaged with Andrographis paniculata extract or andrographolide

“…Whereas the particulate antigen used in our investigation was an intracellular pathogen, S. typhimurium, used as model for human typhoid, and that is also responsible for serious economic losses in food-producing animals [15][16][17], Puri et al [5] used a non-invasive particulate antigen viz., sheep RBCs in their study that still required validation in an infectious disease model. Therefore, the present study may be considered to represent an extension of the study published by Puri et al [5].…”

“…In this investigation, we evaluated the immunomodulatory activities of an ethanolic extract of A. paniculata (APE) and andrographolide (AND), one of the bioactive principles, administered by the oral route in mice immunised with an inactivated Salmonella typhimurium vaccine, the latter having been previously reported to induce only humoral (antibody) response but little or no cell-mediated immune response or immunity (CMI) in the mouse model [15][16][17], although in chickens, a killed Salmonella enteritidis vaccine was reported to induce splenocyte lymphocyte proliferation following stimulation with Con A, a T-cell mitogen, in an apparent agedependent manner [23]. We opted for the mouse model for this investigation because of the demonstrated inability of the killed Salmonella vaccines to induce CMI in this model.…”