Efficacy of Multivalent, Cochleate-Based Vaccine against Salmonella Infantis, S. Enteritidis and S. Typhimurium in Laying Hens

Abstract

Salmonella enterica is an important foodborne pathogen. Commercial poultry are the main reservoirs of Salmonella enterica, leading to the contamination of food and outbreaks in humans. The vaccination of chickens is one of the most important strategies to reduce the number of Salmonella in poultry farms. Unfortunately, commercial vaccines have not been fully effective in controlling the spread and do not contain all the Salmonella serovars that circulate on farms. In this study, we evaluate a new, cochleate-based, trivalent injectable vaccine against S. Enteritidis, S. Typhimurium and S. Infantis, describing the vaccine security, capacity to induce specific anti-Salmonella serovar IgY and the gene expression of immune markers related to CD4 and CD8 T-cell-mediated immunity. Efficacy was evaluated through oral challenges performed separately for each Salmonella serotype. The efficacy and safety of the trivalent vaccine was proven under controlled conditions. The vaccine has no local or systemic reactions or adverse effects on poultry performance related to the vaccine. The vaccine provided significantly increased serum IgY titer levels, significantly reduced Salmonella CFU/g present in the cecum and an increased CD4+/CD8+ ratio in vaccinated animals when challenged with S. Infantis, S. Enteritidis and S. Typhimurium. These results indicate that this new trivalent vaccine does not generate adverse effects in poultry and produces an increase in neutralizing antibodies against the three Salmonella serovars.

Fighting Salmonella Infantis: bacteriophage-driven cleaning and disinfection strategies for broiler farms

“…In this line, the use of S . Infantis vaccines has been studied, either as a serovar-specific vaccine or for cross immunization across Salmonella serovars ( Eeckhaut et al, 2018 ; Crouch et al, 2020a , b ; Sáenz et al, 2022 ), showing promising results in the reduction of S . Infantis fecal shedding and internal colonization in both layer and breeder hens ( Crouch et al, 2020a , b ).…”

“…Infantis is mainly related to broilers, and there are currently no commercial live vaccines available against S . Infantis in broilers ( Sáenz et al, 2022 ). Thus, S .…”

Salmonella Enteritidis Subunit Vaccine Candidate Based on SseB Protein Co-Delivered with Simvastatin as Adjuvant

“…Salmonellosis leads to heavy economic loss and is a threat to human health [25,26]. S. Enteritidis is one of the most common serotypes of salmonellosis in humans, despite the implementation of control and prevention measures [27]. Vaccination is an important and effective method to control and prevent salmonellosis.…”

Holistic Strategies to Control Salmonella Infantis: An Emerging Challenge in the European Broiler Sector

“…The efficacy of the vaccine was evaluated after a double-dose vaccination program at 6 and 9 weeks of age. The results demonstrated a significant decrease in cecal colonization after the challenge, indicating the vaccine's effectiveness [131]. Finally, Maiti et al ( 2022) developed a trivalent outer membrane vesicle (OMV) vaccine (S. Enteritidis, S. Typhimurium, and S. Gallinarum), with the aim of achieving long-term broad-spectrum protection against most prevalent Salmonella serovars, including S. Infantis.…”

“…The efficacy of the vaccine was evaluated after a double-dose vaccination program at 6 and 9 weeks of age. The results demonstrated a significant decrease in cecal colonization after the challenge, indicating the vaccine’s effectiveness [ 131 ]. Finally, Maiti et al (2022) developed a trivalent outer membrane vesicle (OMV) vaccine ( S .…”