Reduction of Salmonella prevalence at slaughter in Lawsonia intracellularis co-infected swine herds by Enterisol® Ileitis vaccination

Abstract

Salmonella spp. remains a wide-spread pathogen among pig herds and its control has major impact on food borne Salmonella infections in humans. The objective of the study was to investigate the influence of an Enterisol ® Ileitis vaccination on Salmonella seroprevalence in Lawsonia intracellularis (L. intracellularis) and Salmonella spp. coinfected pig herds under field conditions.This study compared vaccinated and non-vaccinated pigs of consecutive piglet batches, housed on four different finishing units. Prior to study start, endemic field infections of L. intracellularis and Salmonella spp. were confirmed by serology in the nursery and in all finishing units. Field infection of L. intracellularis occurred at the middle of the nursery phase.In total twenty-five batches of finishing pigs were included in the study, pigs were investigated for four (nonvaccinated group, n ¼ 9) or six months (vaccinated group, n ¼ 16). The primary outcome parameter was Salmonella serology (antibody titers) at the end of fattening. Secondary parameters comprised serology for L. intracellularis and performance parameters, including average daily weight gain (g), duration of fattening period (days), feed conversion (kg/kg) and mortality (%).A total of 709 blood samples were assessed, deriving from vaccinated (n ¼ 439) and non-vaccinated finishing pigs (n ¼ 270). Evaluation of the antibody titers demonstrated that vaccination significantly reduced the Salmonella seroprevalence in the finishing pigs on all four farms. The average OD% values were reduced from 32.7% to 13.4% in addition to a reduced variability in the vaccinated pigs compared to the control group. The Salmonella category of all finishing farms improved by at least one category in accordance with the German Salmonella monitoring program. In addition, vaccination had a positive tendency on the average daily weight gain, fattening duration and reduced mortality.In conclusion, this study demonstrates that vaccination with Enterisol ® Ileitis has a positive and direct impact on reduction of Salmonella infection in co-infected herds.

New Formulation of a Subunit Vaccine Candidate against Lawsonia intracellularis Increases Humoral and Cellular Immune Responses

“…A live attenuated vaccine, Enterisol ® Ileitis (Boehringer Ingelheim Animal Health USA Inc., Duluth, GA, USA); and an inactivated one, Porcilis ® Ileitis (Merck Animal Health, Kenilworth, NJ, USA). Both vaccines have offered some protection degree to vaccinated animals [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. However, the production of these kinds of vaccines requires bacterial replication in eukaryotic cell culture, which implies high production costs associated with the particularly challenging microorganism isolation and in vitro culture conditions [ 18 , 19 ].…”

Microbiota of vaccinated and non-vaccinated clinically inconspicuous and conspicuous piglets under natural Lawsonia intracellularis infection

“…Enterisol ® Ileitis is a licensed oral, live-attenuated vaccine that confers reduction of intestinal lesions caused by L. intracellularis , growth variability and loss of weight associated with the disease. Recent findings show that oral vaccination with Enterisol ® Ileitis seems to additionally alter the intestinal microbiota ( 12 , 24 , 25 ). Finally, an even and diverse microbiota community seems to benefit pigs infected with L. intracellularis ( 26 ).…”

EFEITO DA VACINAÇÃO PARA Salmonella Typhimurium E Lawsonia intracellularis NO DESEMPENHO ZOOTÉCNICO DE SUÍNOS EM CRESCIMENTO E TERMINAÇÃO

“…observaram que suínos soropositivos para L. Salmonella Typhimurium em animais co-infectados, sugerindo que a L. intracellularis pode ocasionar o aumento da inflamação favorecendo à infecção por Salmonella Typhimurium(LEITE et al, 2018). Em outro trabalho, suínos vacinados contra L. intracellularis tiveram os valores médios de Salmonella menores do que o grupo controle, redução de 59,9%, demostrando impacto positivo em lotes co-infectados(MESCHEDE et al, 2021).Estudos em sistemas de produção dependem da contaminação natural, não sendo possível saber qual a carga de contaminação do animal. Em nosso trabalho uma hipótese para não ter sido observado diferenças entre os protocolos de vacinação e o grupo controle é a variabilidade da contaminação natural.…”