The Campylobacter jejuni chemoreceptor Tlp10 has a bimodal ligand-binding domain and specificity for multiple classes of chemoeffectors

Campylobacter jejuni is a bacterial pathogen that is a common cause of enteritis in humans. We identified a previously uncharacterized type of sensory domain in the periplasmic region of the C. jejuni chemoreceptor Tlp10, termed the DAHL domain, that is predicted to have a bimodular helical architecture. Through two independent ligand-binding sites in this domain, Tlp10 responded to molecular aspartate, isoleucine, fumarate, malate, fucose, and mannose as attractants and to arginine, galactose, and thiamine as repellents. Tlp10 also recognized glycan ligands when present as terminal and intermediate residues of complex structures, such as the fucosylated human ganglioside GM1 and Lewisa antigen. A tlp10 mutant strain lacking the ligand-binding sites was attenuated in its ability to colonize avian caeca and to adhere to cultured human intestinal cells, indicating the potential involvement of the DAHL domain in host colonization and disease. The Tlp10 intracellular signaling domain interacted with the scaffolding proteins CheV and CheW, which couple chemoreceptors to intracellular signaling machinery, and with the signaling domains of other chemoreceptors, suggesting a key role for Tlp10 in signal transduction and incorporation into sensory arrays. We identified the DAHL domain in other bacterial signal transduction proteins, including the essential virulence induction protein VirA from the plant pathogen Agrobacterium tumefaciens. Together, these results suggest a potential li...
Source: Signal Transduction Knowledge Environment - Category: Science Authors: Tags: STKE Research Articles Source Type: news

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Abstract Spotty Liver Disease (SLD) is an emerging disease of serious concern in the egg production industry, as it causes significant egg loss and mortality in layer hens. The causative agent is a newly identified Gram-negative bacterium, Campylobacter hepaticus, and knowledge about C. hepaticus pathogenesis and the potential for vaccine development is still in its infancy. Current detection methods for SLD, such as PCR and culturing, only detect an active infection and will not give any indication of a past infection from which the bacteria have been cleared. An immunological assay, on the other hand, can provid...
Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research
Campylobacter jejuni monitors intestinal metabolites produced by the host and microbiota to initiate intestinal colonization of avian and animal hosts for commensalism and infection of humans for diarrheal disease. We previously discovered that C. jejuni has the capacity to spatially discern different intestinal regions by sensing lactate and the short-chain...
Source: Proceedings of the National Academy of Sciences - Category: Science Authors: Tags: Biological Sciences Source Type: research
Authors: Campana R, Baffone W Abstract Campylobacter acts using complex strategies to establish and promote intestinal infections. After ingestion via contaminated foods, this bacterium invades and can survive within the intestinal cells, also inducing epithelial translocation of non-invasive intestinal bacteria. In this investigation, the ability of human and avian C. jejuni and C. coli isolates to survive within two different intestinal epithelial cells lines, Caco-2 and INT 407, as well as the intestinal translocation phenomenon, was assessed. Our data demonstrated that both C. jejuni and C. coli strains survive...
Source: Advances in Experimental Medicine and Biology - Category: Research Tags: Adv Exp Med Biol Source Type: research
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Source: TIME: Health - Category: Consumer Health News Authors: Tags: Uncategorized COVID-19 Source Type: news
Publication date: Available online 24 March 2020Source: Veterinary MicrobiologyAuthor(s): E. Cuevas-Ferrando, P. Guirado, E. Miró, Y. Iglesias-Torrens, F. Navarro, T.S. Alioto, J. Gómez-Garrido, C. Madrid, C. Balsalobre
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research
Abstract Enteric illnesses remain the second largest source of communicable diseases worldwide, and wild birds are suspected sources for human infection. This has led to efforts to reduce pathogen spillover through deterrence of wildlife and removal of wildlife habitat, particularly within farming systems, which can compromise conservation efforts and the ecosystem services wild birds provide. Further, Salmonella spp. are a significant cause of avian mortality, leading to additional conservation concerns. Despite numerous studies of enteric bacteria in wild birds and policies to discourage birds from food systems,...
Source: Biological Reviews of the Cambridge Philosophical Society - Category: Biology Authors: Tags: Biol Rev Camb Philos Soc Source Type: research
In this study, we investigated whether heritable differences in colonization of inbred chicken lines by Campylobacter jejuni are associated with differences in caecal microbiota. We performed homologous and heterologous caecal microbiota transplants between line 61 (resistant) and line N (susceptible), by orally administering caecal contents collected from 3-week-old donors to day-of-hatch chicks. Recipient birds were challenged (day 21) with C. jejuni 11168H. In birds given homologous microbiota, the differential resistance of lines to C. jejuni colonization was reproduced. Contrary to our hypothesis, transfer of caecal m...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research
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Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
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Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
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Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research
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