Identification of a microbial sub-community from the feral chicken gut that reducesSalmonellacolonization and improves gut health in a gnotobiotic chicken model (original) (raw)
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Applied and Environmental Microbiology, 2018
Salmonella is estimated to cause one million foodborne illnesses in the United States every year. Salmonella-contaminated poultry products are one of the major sources of salmonellosis. Given the critical role of the gut microbiota in Salmonella transmission, a manipulation of the chicken intestinal microenvironment could prevent animal colonization by the pathogen. In Salmonella, the global regulator gene fnr (fumarate nitrate reduction) regulates anaerobic metabolism and is essential for adapting to the gut environment. This study tested the hypothesis that an attenuated Fnr mutant of Salmonella enterica serovar Typhimurium (attST) or prebiotic galacto-oligosaccharides (GOS) could improve resistance to wild-type Salmonella via modifications to the structure of the chicken gut microbiome. Intestinal samples from a total of 273 animals were collected weekly for 9 weeks to evaluate the impact of attST or prebiotic supplementation on microbial species of the cecum, duodenum, jejunum, and ileum. We next analyzed changes to the gut microbiome induced by challenging the animals with a wild-type Salmonella serovar 4,[5],12:r:Ϫ (Nal r) strain and determined the clearance rate of the virulent strain in the treated and control groups. Both GOS and the attenuated Salmonella strain modified the gut microbiome but elicited alterations of different taxonomic groups. The attST produced significant increases of Alistipes and undefined Lactobacillus, while GOS increased Christensenellaceae and Lactobacillus reuteri. The microbiome structural changes induced by both treatments resulted in a faster clearance after a Salmonella challenge. IMPORTANCE With an average annual incidence of 13.1 cases/100,000 individuals, salmonellosis has been deemed a nationally notifiable condition in the United States by the Centers for Disease Control and Prevention (CDC). Earlier studies demonstrated that Salmonella is transmitted by a subset of animals (supershedders). The supershedder phenotype can be induced by antibiotics, ascertaining an essential role for the gut microbiota in Salmonella transmission. Consequently, modulation of the gut microbiota and modification of the intestinal microenvironment could assist in preventing animal colonization by the pathogen. Our study demonstrated that a manipulation of the chicken gut microbiota by the administration of an attenuated Salmonella strain or prebiotic galacto-oligosaccharides (GOS) can promote resistance to Salmonella colonization via increases of beneficial microorganisms that translate into a less hospitable gut microenvironment.
Probiotics/direct fed microbials for Salmonella control in poultry
Food Research International, 2012
Bacterial antimicrobial resistance in both the medical and agricultural fields has become a serious problem worldwide. During the last 15 years, our laboratories have worked toward the identification of probiotic candidates for poultry which can actually displace Salmonella and other enteric pathogens which have colonized the gastrointestinal tract of chickens and turkeys, indicating that selection of therapeutically efficacious probiotic cultures with marked performance benefits in poultry is possible, and that defined cultures can sometimes provide an attractive alternative to conventional antimicrobial therapy. Our studies have been focused on specific pathogen reduction, performance under commercial conditions, and effects on both idiopathic and defined enteritis. We have also confirmed that selected heat-resistant spore-forming Bacillus species can markedly reduce Salmonella and Clostridium when administered in very high numbers, and we have developed a novel and simple technique for obtaining cultured Bacillus spore counts, providing a cost-effective feed-stable inclusion in commercial poultry diets. In order to select even more effective isolates, we are still currently focused on the mechanistic action of the Lactobacillus probiotic previously developed as well as new Bacillus candidates. Current indications are that mechanism of action involves rapid activation of innate host immune responses, providing an exciting possibility for identification of vastly superior and more potent probiotics. In this review, we summarize the safety and efficacy of individual monocultures for prophylactic and/or therapeutic efficacy against Salmonella infections under both laboratory and field conditions as well as the development of a novel, cost-effective, feed-stable direct-fed microbials (DFM) with potential for widespread utilization and improved production, delivery and clinical efficacy for animal use.
Applied and environmental microbiology, 2017
Salmonella is estimated to cause one million food-borne illnesses in the United States every year. Salmonella-contaminated poultry products are one of the major sources of Salmonellosis. Given the critical role of the gut microbiota in Salmonella transmission, manipulation of the chicken intestinal microenvironment could prevent animal colonization by the pathogen. In Salmonella, the global regulator gene fnr (Fumarate Nitrate Reduction) regulates anaerobic metabolism, and is essential for adapting to the gut environment. This study tested the hypothesis that an attenuated Fnr-mutant of Salmonella Typhimurium (attST), or the prebiotic galacto-oligosaccharides (GOS) could improve resistance to wild-type Salmonella via modifications to the structure of the chicken gut microbiome. Intestinal samples from a total of 273 animals were collected weekly for 9 weeks to evaluate the impact of attST or prebiotic supplementation on microbial species of cecum, duodenum, jejunum, and ileum. We ne...
The Journal of Applied Poultry Research, 2006
Salmonella infections are mainly asymptomatic in poultry but are associated with widespread human illness from this source. Therefore, there is continuing interest in finding ways of preventing flock infection and, hence, contamination of poultry products with salmonellas. This review considers aspects of Salmonella carriage in poultry and host interactions that may be exploitable in the future to improve existing control measures. These include factors involved in colonization of the gastrointestinal tract, the role of competitive exclusion and probiotic treatments, and enhancement of intestinal immunity.
Background: The gut microbiota plays an important role in the colonisation resistance and invasion of pathogens. Salmonella Typhimurium has the potential to establish a niche by displacing the microbiota in the chicken gut causing continuous faecal shedding that can result in contaminated eggs or egg products. In the current study, we investigated the dynamics of gut microbiota in laying chickens during Salmonella Typhimurium infection. The optimisation of the use of an infeed probiotic supplement for restoration of gut microbial balance and reduction of Salmonella Typhimurium load was also investigated.
Infection and Immunity, 2011
In commercial poultry production, there is a lack of natural flora providers since chickens are hatched in the clean environment of a hatchery. Events occurring soon after hatching are therefore of particular importance, and that is why we were interested in the development of the gut microbial community, the immune response to natural microbial colonization, and the response to Salmonella enterica serovar Enteritidis infection as a function of chicken age. The complexity of chicken gut microbiota gradually increased from day 1 to day 19 of life and consisted of Proteobacteria and Firmicutes. For the first 3 days of life, chicken cecum was protected by increased expression of chicken -defensins (i.e., gallinacins 1, 2, 4, and 6), expression of which dropped from day 4
Journal of animal science and biotechnology, 2017
The chicken gastrointestinal tract contains a diverse microbiota whose composition and structure play important roles in gut functionality. In this study, microbial shifts resulting from feed supplementation with Bacillus subtilis CSL2 were evaluated in broilers challenged and unchallenged with Salmonella Gallinarum. To analyse bacterial community composition and functionality, 454 GS-FLX pyrosequencing of 16S rRNA gene amplicons was performed. The Quantitative Insights into Microbial Ecology (QIIME) pipeline was used to analyse changes in the faecal microbiota over a 24-h period. A total of 718,204 sequences from broiler chickens were recorded and analysed. At the phylum level, Firmicutes, Bacteroidetes, and Proteobacteria were the predominant bacterial taxa. In Salmonella-infected chickens (SC), Bacteroidetes were more highly abundant compared to control (NC) and Bacillus-treated (BT) chickens. At the genus level, in the NC and BT groups, Lactobacillus was present at high abundanc...
BMC Veterinary Research, 2013
Background: Infection of newly hatched chicks with Salmonella enterica serovar Enteritidis (S. Enteritidis) results in an inflammatory response in the intestinal tract which may influence the composition of gut microbiota. In this study we were therefore interested whether S. Enteritidis induced inflammation results in changes in the cecal microbiota. To reach this aim, we compared the cecal microbiota of non-infected chickens and those infected by S. Enteritidis by pyrosequencing the V3/V4 variable regions of genes coding for 16S rRNA. Results: Cecal microbiota of chickens up to 19 days of life was dominated by representatives of Enterobacteriaceae, Lachnospiraceae and Ruminococcaceae, followed by Lactobacillaceae. The presence of Lachnospiraceae did not change after S. Enteritidis infection. Enterobacteriaceae increased and Ruminococcaceae decreased after S. Enteritidis infection in two independent experiments although these results were not significant. A significant increase in both experiments was observed only for the representatives of Lactobacillaceae which may correlate with their microaerophilic growth characteristic compared to the obligate anaerobes from the families Lachnospiraceae and Ruminococcaceae.
Gastrointestinal microbial ecology and the safety of our food supply as related to Salmonella1,2
Journal of Animal Science, 2007
Salmonella causes an estimated 1.3 million human foodborne illnesses and more than 500 deaths each year in the United States, representing an annual estimated cost to the economy of approximately $2.4 billion. Salmonella enterica comprises more than 2,500 serotypes. With this genetic and environmental diversity, serotypes are adapted to live in a variety of hosts, which may or may not manifest with clinical illness. Thus, Salmonella presents a multifaceted threat to food production and safety. Salmonella have been isolated from all food animals and can cause morbidity and mortality in swine, cattle, sheep, and poultry. The link between human salmonellosis and host animals is most clear in poultry. During the early part of the 20th century, a successful campaign was waged to eliminate fowl typhoid caused by Salmonella Gallinarum/Pullorum. Microbial ecology is much like macroecology; environmental niches are filled by adapted and specialized species. Elimination of S. Gallinarum cleared a niche in the on-farm and intestinal microbial ecology that was quickly exploited by Salmonella Enter
Microorganisms, 2022
Lactobacilli are commonly used as probiotics in poultry to improve production parameters and to increase chicken resistance to enteric infections. However, lactobacilli do not efficiently colonise the chicken intestinal tract, and also, their anti-infection effect in vivo is sometimes questionable. In this study, we therefore evaluated the potential of a mixture of four Lactobacillus species (L. salivarius, L. reuteri, L. ingluviei and L. alvi) for the protection of chickens against Salmonella Enteritidis infection. Whenever the chickens were inoculated by lactobacilli and S. Enteritidis separately, there was no protective effect of lactobacilli. This means that when lactobacilli and S. Enteritidis are exposed to each other as late as in the crop of chickens, lactobacilli did not influence chicken resistance to S. Enteritidis at all. The only positive effect was recorded when the mixture of lactobacilli and S. Enteritidis was used for the inoculation of feed and the feed was anaerob...