Phenotype alterations in the cecal ecosystem involved in the asymptomatic intestinal persistence of paratyphoid Salmonella in chickens

Authors: Kogut, Michael - Mike; FERNANDEZ, MIYAKAWA, MARIANO - Instituto Nacional De Tecnologia Agropecuaria

Submitted to: Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/2023
Publication Date: 9/6/2023
Citation: Kogut, M.H., Fernandez, Miyakawa, M.E. 2023. Phenotype alterations in the cecal ecosystem involved in the asymptomatic intestinal persistence of paratyphoid Salmonella in chickens. Animals. 13. Article 2824. https://doi.org/10.3390/ani13182824.
DOI: https://doi.org/10.3390/ani13182824

Interpretive Summary: Chicks get infected with Salmonella early in life and the microbes are able to survive in the chicks throughout their life. Because of this, Salmonella can be consistently released from the birds and then infect the other chicks. The presence of Salmonella in the chicks, when they go to market, means that Salmonella can get into chicken meat products where they can cause food poisoning in humans. The purpose of this paper is to summarize how Salmonella can survive in chicks for so long without being "seen" by the chick's immune system. We found that Salmonella causes a change in the immune response of the baby chicks so that it is "invisible" to the immune system. Thus, the immune cells cannot attack Salmonella and kill it. These results are important to the pharmaceutical industry because we have identified a specific target to stimulate the bird's immune system and provide protection against infection.

Technical Abstract: The gastrointestinal ecosystem involves interactions between the host, gut microbiota, and external environment. To colonize the gut of poultry, Salmonella must surmount barriers levied by the intestine including mucosal innate immune responses and microbiota-mediated niche restrictions. Accordingly, comprehending Salmonella intestinal colonization in poultry requires an understanding of the pathogen interacts with the intestinal ecosystem. In chickens, the paratyphoid Salmonella have evolved the capacity to survive the initial robust immune response and persist in the avian ceca for months without triggering clinical signs. The persistent phase of a Salmonella infection in the avian host involves a complex balance of antagonistic and cooperative host defense strategies. The initial phase (4-48 h post-infection) in the chicken cecum is characteristically an innate pro-inflammatory response that controls bacterial invasion. The second phase (4-14 days post-infection) is characterized by an expansion of the T regulatory cell population in the cecum of Salmonella-infected chickens followed by distinct alterations of the immune and metabolic pathways that dramatically changes the local immunometabolic phenotype from pro-inflammatory to an anti-inflammatory environment. Thus, paratyphoid Salmonella in chickens have evolved a unique survival strategy in poultry that minimizes host defenses (disease resistance) during the initial infection and then exploits and/or induces a dramatic immunometabolic reprogramming in the cecum that alters the host defense to disease tolerance. These results provide a basic understanding of how host metabolic adaptations during infection promote co-operative defenses between a host and enteric pathogens to drive asymptomatic carriage of the bacterial pathogen.