Taxonomy of the <i>Helicobacter</i> Genus

Solnick, Jay V.; Vandamme, Peter

doi:10.1128/9781555818005.ch5

Cited by 16 publications

(6 citation statements)

References 73 publications

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“…The three predominant categories observed were the microaerophiles, obligate anaerobes, and facultative anaerobes (Figure S3). Interestingly, the relative percentage abundance of microaerophiles increases at TP2 (Solnick and Vandamme (2001); Gueneau and Loiseauxdegoer (2002)), coinciding with the peak levels of P. cynomolgi, which is also a microaerophile.…”

Section: Gut Bacterial Diversity In Rhesus Macaquesmentioning

confidence: 80%

Malaria disrupts the rhesus macaque gut microbiome

Farinella

Kaur

Tran

et al. 2023

Front. Cell. Infect. Microbiol.

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Previous studies have suggested that a relationship exists between severity and transmissibility of malaria and variations in the gut microbiome, yet only limited information exists on the temporal dynamics of the gut microbial community during a malarial infection. Here, using a rhesus macaque model of relapsing malaria, we investigate how malaria affects the gut microbiome. In this study, we performed 16S sequencing on DNA isolated from rectal swabs of rhesus macaques over the course of an experimental malarial infection with Plasmodium cynomolgi and analyzed gut bacterial taxa abundance across primary and relapsing infections. We also performed metabolomics on blood plasma from the animals at the same timepoints and investigated changes in metabolic pathways over time. Members of Proteobacteria (family Helicobacteraceae) increased dramatically in relative abundance in the animal’s gut microbiome during peak infection while Firmicutes (family Lactobacillaceae and Ruminococcaceae), Bacteroidetes (family Prevotellaceae) and Spirochaetes amongst others decreased compared to baseline levels. Alpha diversity metrics indicated decreased microbiome diversity at the peak of parasitemia, followed by restoration of diversity post-treatment. Comparison with healthy subjects suggested that the rectal microbiome during acute malaria is enriched with commensal bacteria typically found in the healthy animal’s mucosa. Significant changes in the tryptophan-kynurenine immunomodulatory pathway were detected at peak infection with P. cynomolgi, a finding that has been described previously in the context of P. vivax infections in humans. During relapses, which have been shown to be associated with less inflammation and clinical severity, we observed minimal disruption to the gut microbiome, despite parasites being present. Altogether, these data suggest that the metabolic shift occurring during acute infection is associated with a concomitant shift in the gut microbiome, which is reversed post-treatment.

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Section: Gut Bacterial Diversity In Rhesus Macaquesmentioning

confidence: 80%

Malaria disrupts the rhesus macaque gut microbiome

Farinella

Kaur

Tran

et al. 2023

Front. Cell. Infect. Microbiol.

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“…Phylogenetically, CDT from H. cinaedi is more similar to the C. fetus II clade than the Helicobacter clade. Although H. cinaedi was recently reclassified as a Helicobacter species after initial classification as a Campylobacter species (Vandamme et al, 1991 ), it would be expected to be most similar to H. bilis based on the 16S rRNA phylogeny (Solnick and Vandamme, 2001 ). An interesting example of horizontal gene transfer within only one of the three CDT genes was found for C. lari , which is broken into three distinct clades for CdtC, while only a single clade with one outlier is observed in both CdtA and CdtB.…”

Section: Phylogenetic Analysis Of Cdt Subfamiliesmentioning

confidence: 99%

Bacterial toxin modulation of the eukaryotic cell cycle: are all cytolethal distending toxins created equally?

Gargi

Reno

Blanke

2012

Front. Cell. Inf. Microbio.

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The cytolethal distending toxins (CDTs) comprise a family of intracellular-acting bacterial protein toxins whose actions upon eukaryotic cells result in several consequences, the most characteristic of which is the induction of G2/M cell cycle arrest. Most CDTs are hetero-tripartite assemblies of CdtA, CdtB, and CdtC, with CdtB required for CDT-mediated cell cycle arrest. Several lines of evidence indicate that CdtA and CdtC are required for the optimal intracellular activity of CdtB, although the exact functional roles of CdtA and CdtC remain poorly understood. The genes encoding the CDTs have been identified in a diverse array of Gram-negative pathogenic bacteria. More recently, the genes encoding several CdtB subunits have been associated with alternatively linked subunits resembling the B-subunits of pertussis toxin. Although the CDTs are generally considered to all function as bacterial genotoxins, the extent to which individual members of the CDTs employ similar mechanisms of cell surface binding, uptake, and trafficking within sensitive cells is poorly understood. Recently, data have begun to emerge suggesting differences in the molecular basis by which individual CDTs interact with and enter host cells, suggesting the possibility that CDTs possess properties reflecting the specific niches idiosyncratic to those CDT bacterial pathogens that produce them. The extent to which functional differences between individual CDTs reflect the specific requirements for intoxicating cells and tissues within the diverse range of host microenvironments colonized by CDT-producing pathogenic bacteria remains to be experimentally explored.

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“…Helicobacter pylori is a Gram-negative spiral-shaped bacterium, which colonizes the human stomach [1][2][3] , leading to chronic mucosal inflammation and thus playing a pivotal role in the pathogenesis of chronic gastritis-related diseases (peptic ulcer diseases, gastric adenocarcinoma, and mucosa-associated lymphoid tissue [MALT] lymphoma). 4 Certain H. pylori-related gastric mucosa alterations have emphasized significance in setting up the histologic diagnosis.…”

Section: Introductionmentioning

confidence: 99%