Salmonellosis outbreaks are global issues primarily associated with the consumption of poultry products, which may be infected with Salmonella. The use of lytic bacteriophages could be a safe and effective approach to reduce Salmonella prevalence in poultry and subsequently the incidence in humans. This study examined the value of prophylactic phage treatment on Salmonella levels in chickens and the effect of such treatment on their overall gut microbiome.
View Article and Find Full Text PDFAvian pathogenic Escherichia coli (APEC) causes colibacillosis, the main bacterial disease in poultry leading to significant economic losses worldwide. Antibiotic treatments favor the emergence of multidrug-resistant bacteria, and preventive measures are insufficient to control the disease. There is increasing interest in using the potential of bacteriophages, not only for phage therapy but also for prevention and biocontrol.
View Article and Find Full Text PDFManaging Salmonella enterica Enteritidis (SE) carriage in chicken is necessary to ensure human food safety and enhance the economic, social and environmental sustainability of chicken breeding. Salmonella can contaminate poultry products, causing human foodborne disease and economic losses for farmers. Both genetic selection for a decreased carriage and gut microbiota modulation strategies could reduce Salmonella propagation in farms.
View Article and Find Full Text PDFIn chicken, Salmonella Enteritidis and Salmonella Typhimurium, the two main serotypes isolated in human infections, can persist in the host organism for many weeks and up to many years without causing any symptoms. This persistence generally occurs after a short systemic infection that may either lead to death of very young birds or develop into cecal asymptomatic persistence, which is often accompanied by a high level of bacterial excretion, facilitating Salmonella transmission to counterparts. Here we describe two models of chick infection.
View Article and Find Full Text PDFHeterogeneity of infection and extreme shedding patterns are common features of animal infectious diseases. Individual hosts that are super-shedders are key targets for control strategies. Nevertheless, the mechanisms associated with the emergence of super-shedders remain largely unknown.
View Article and Find Full Text PDFCarriage of Salmonella is often associated with a high level of bacterial excretion and generally occurs after a short systemic infection. However, we do not know whether this systemic infection is required or whether the carrier-state corresponds to continuous reinfection or real persistence in caecal tissue. The use of a Salmonella Enteritidis bamB mutant demonstrated that a carrier-state could be obtained in chicken in the absence of systemic infection.
View Article and Find Full Text PDFSalmonella enterica serotype Senftenberg (S. Senftenberg) has recently become more frequent in poultry flocks. Moreover some strains have been implicated in severe clinical cases.
View Article and Find Full Text PDFSalmonella virulence in animals depends on effectors injected by Type III Secretion Systems (T3SSs). In this report we demonstrate that Salmonella mutants that are unable to deliver effectors are also compromised in infection of Arabidopsis thaliana plants. Transcriptome analysis revealed that in contrast to wild type bacteria, T3SS mutants of Salmonella are compromised in suppressing highly conserved Arabidopsis genes that play a prominent role during Salmonella infection of animals.
View Article and Find Full Text PDFToll-like receptor 4 (TLR4), which recognizes lipopolysaccharide from Gram-negative bacteria, plays a major role in resistance of mice and humans to Salmonella infection. In chickens, Salmonella may establish a carrier state whereby bacteria are able to persist in the host organism without triggering clinical signs. Based on cellular morphological parameters, we developed a method, without using antibodies, to separate three cecal cell subpopulations: lymphocytes, enterocytes, and a population encompassing multiple cell types.
View Article and Find Full Text PDFChicken's ability to carry Salmonella without displaying disease symptoms leads to an invisible propagation of Salmonella in poultry stocks. Using chicken lines more resistant to carrier state could improve both animal health and food safety. Previous studies identified several QTL for resistance to carrier state.
View Article and Find Full Text PDFIncreasing resistance to acute salmonellosis (defined as bacteraemia in animals showing symptoms) is not sufficient for food safety, because of the risk of carrier state (when animals excrete bacteria without showing any symptoms). Increased resistance to Salmonella carrier state is therefore needed. Two experiments of divergent selection on resistance at a younger and a later age lead to significant differences between lines and allowed estimating genetic parameters on 4262 animals.
View Article and Find Full Text PDFExpression of the virB operon, encoding the type IV secretion system required for Brucella suis virulence, occurred in the acidic phagocytic vacuoles of macrophages and could be induced in minimal medium at acidic pH values. To analyze the production of VirB proteins, polyclonal antisera against B. suis VirB5 and VirB8 were generated.
View Article and Find Full Text PDFCross-protection induced by primary infection with Abortusovis and Gallinarum was examined against challenge injection with these Salmonella serotypes as well as with Dublin and Choleraesuis, the other virulent serotypes. Abortusovis induced efficient protection against the other Salmonella. Gallinarum was ineffective against Choleraesuis.
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