Potent Antagonism of Escherichia Coli, Bacteroides Ovatus, Fusobacterium Varium, and Enterococcus Faecalis, Alone or in Combination, for Enteropathogens in Anaerobic Continuous Flow Cultures

Ushijima, Tsutomu; Ozaki, Yoshihiko

doi:10.1099/00222615-22-2-157

Cited by 17 publications

(7 citation statements)

References 10 publications

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“…Second, commensal bacteria even function antagonistically against pathogenic bacteria, a phenomenon known as colonization resistance. Continuous‐flow experiments using a smaller subset of commensal bacteria revealed that this effect is due to competition for nutrients and spaces that are sustained by the dynamics of an intermicrobial metabolic network (Ushijima and Ozaki, 1986, 1988). Perturbation of commensal bacteria due to the use of antibiotics causes antibiotic‐associated diarrhea (Bergogne‐Berezin, 2000) by allowing pathogenic bacteria such as Clostridium difficile to proliferate.…”

Section: Commensal Bacterial Flora As An Integral Part Of the Host Dementioning

confidence: 99%

Robustness trade‐offs and host–microbial symbiosis in the immune system

Kitano

Oda

2006

Molecular Systems Biology

118

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The immune system provides organisms with robustness against pathogen threats, yet it also often adversely affects the organism as in autoimmune diseases. Recently, the molecular interactions involved in the immune system have been uncovered. At the same time, the role of the bacterial flora and its interactions with the host immune system have been identified. In this article, we try to reconcile these findings to draw a consistent picture of the host defense system. Specifically, we first argue that the network of molecular interactions involved in immune functions has a bow-tie architecture that entails inherent trade-offs among robustness, fragility, resource limitation, and performance. Second, we discuss the possibility that commensal bacteria and the host immune system constitute an integrated defense system. This symbiotic association has evolved to optimize its robustness against pathogen attacks and nutrient perturbations by harboring a broad range of microorganisms. Owing to the inherent propensity of a host immune system toward hyperactivity, maintenance of bacterial flora homeostasis might be particularly important in the development of preventive strategies against immune disorders such as autoimmune diseases.

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Section: Commensal Bacterial Flora As An Integral Part Of the Host Dementioning

confidence: 99%

Robustness trade‐offs and host–microbial symbiosis in the immune system

Kitano

Oda

2006

Molecular Systems Biology

118

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“…With respect to its human host, this Gram-negative, nonspore forming, obligately anaerobic microorganism plays both beneficial and pathological roles. F. varium is known to be a potent antagonist of pathogenic bacteria such as Shigella [17] and Salmonella [18,19]. The organism is capable of fermenting amino acids and glucose [20], while many gut microorganisms selectively derive their energy either from carbohydrates or from proteins [21].…”

Section: Introductionmentioning

confidence: 99%

Proteomic investigation of amino acid catabolism in the indigenous gut anaerobe Fusobacterium varium

Potrykus¹,

White²,

Bearne³

2008

Proteomics

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The butyrate-producing anaerobe Fusobacterium varium is an integral constituent of human gut microflora. Unlike many gut microorganisms, F. varium is capable of fermenting both amino acids and glucose. Although F. varium has been implicated in beneficial as well as pathological bacterium-host interactions, its genome has not been sequenced. To obtain a better understanding of the metabolic processes associated with amino acid fermentation by F. varium, we used a gel-based proteomic approach to examine the changes in the soluble proteome accompanying the utilization of eight different growth substrates: glucose, L-and D-glutamate, L-histidine, L-and D-lysine, and L-and D-serine. Using LC-MS/MS to analyze ,25% of the detected protein spots, we were able to identify 47 distinct proteins. While the intracellular concentrations of enzymes characteristic of a catabolic pathway for a specific amino acid were selectively increased in response to the presence of an excess of that amino acid in the growth medium, the concentrations of the core acetate-butyrate pathway enzymes remained relatively constant. Our analysis revealed (i) high intracellular concentrations of glutamate mutase and b-methylaspartate ammonia-lyase under all growth conditions, underscoring the importance of the methylaspartate pathway of glutamate catabolism in F. varium (ii) the presence of two enzymes of the hydroxyglutarate pathway of glutamate degradation in the proteome of F. varium ((R)-2-hydroxyglutaryl-CoA dehydratase and NAD-specific glutamate dehydrogenase) specifically when Lglutamate was the main energy source (iii) the presence of genes in the genome of F. varium encoding each of the enzymes of the hydroxyglutarate pathway (iv) the presence of both L-and Dserine ammonia-lyases (dehydratases) which permit F. varium to thrive on either L-or D-serine, respectively, and (v) the presence of aspartate-semialdehyde dehydrogenase and dihydrodipicolinate synthase, consistent with the ability of F. varium to synthesize meso-2,6-diaminopimelic acid as a component of its peptidoglycan. Proteins involved in other cellular processes, including oxidation-reduction reactions, protein synthesis and turnover, and transport were also identified.

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“…We identified only few potentially pathogenic toxin coding genes from Fusobacterium (Additional file 7 ). Considering that F. varium has been shown to affect its human host in a beneficial manner by antagonizing colonization by pathogenic agents [ 92 ], we suggest that an important role of the gut Fusobacteria could be the formation of biofilms and colonization resistance, without representing a serious pathogenic threat. We identified the pathogenicity genes perfringolysin O and phospholipase C in the gut microbiome from C. perfringens .…”

Section: Discussionmentioning

confidence: 99%

Protective role of the vulture facial skin and gut microbiomes aid adaptation to scavenging

et al. 2018

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BackgroundVultures have adapted the remarkable ability to feed on carcasses that may contain microorganisms that would be pathogenic to most other animals. The holobiont concept suggests that the genetic basis of such adaptation may not only lie within their genomes, but additionally in their associated microbes. To explore this, we generated shotgun DNA sequencing datasets of the facial skin and large intestine microbiomes of the black vulture (Coragyps atratus) and the turkey vulture (Cathartes aura). We characterized the functional potential and taxonomic diversity of their microbiomes, the potential pathogenic challenges confronted by vultures, and the microbial taxa and genes that could play a protective role on the facial skin and in the gut.ResultsWe found microbial taxa and genes involved in diseases, such as dermatitis and pneumonia (more abundant on the facial skin), and gas gangrene and food poisoning (more abundant in the gut). Interestingly, we found taxa and functions with potential for playing beneficial roles, such as antilisterial bacteria in the gut, and genes for the production of antiparasitics and insecticides on the facial skin. Based on the identified phages, we suggest that phages aid in the control and possibly elimination, as in phage therapy, of microbes reported as pathogenic to a variety of species. Interestingly, we identified Adineta vaga in the gut, an invertebrate that feeds on dead bacteria and protozoans, suggesting a defensive predatory mechanism. Finally, we suggest a colonization resistance role through biofilm formation played by Fusobacteria and Clostridia in the gut.ConclusionsOur results highlight the importance of complementing genomic analyses with metagenomics in order to obtain a clearer understanding of the host-microbial alliance and show the importance of microbiome-mediated health protection for adaptation to extreme diets, such as scavenging.Electronic supplementary materialThe online version of this article (10.1186/s13028-018-0415-3) contains supplementary material, which is available to authorized users.

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Potent Antagonism of Escherichia Coli, Bacteroides Ovatus, Fusobacterium Varium, and Enterococcus Faecalis, Alone or in Combination, for Enteropathogens in Anaerobic Continuous Flow Cultures

Cited by 17 publications

References 10 publications

Robustness trade‐offs and host–microbial symbiosis in the immune system

Robustness trade‐offs and host–microbial symbiosis in the immune system

Proteomic investigation of amino acid catabolism in the indigenous gut anaerobe Fusobacterium varium

Protective role of the vulture facial skin and gut microbiomes aid adaptation to scavenging

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