Gardnerella vaginalis diversity and ecology in relation to vaginal symptoms

Schellenberg, John; Patterson, Mo H.; Hill, Janet E.

doi:10.1016/j.resmic.2017.02.011

Cited by 42 publications

(43 citation statements)

References 67 publications

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“…Nevertheless, we see the need to put these definitions in a larger context and compare them to already published attempts to classify G. vaginalis lineages. Clades 1 and 2 defined here include isolates reported for clades 1 and 2 in Ahmed et al (2012) and clades C and B (respectively) reported by Schellenberg et al (2017). Our clade 3 corresponded to clades 3 and 4 in Ahmed et al (2012) and clades D and A (respectively) reported by Schellenberg et al (2017).…”

Section: Discussionmentioning

confidence: 66%

“…() and clades C and B (respectively) reported by Schellenberg et al. (). Our clade 3 corresponded to clades 3 and 4 in Ahmed et al.…”

Section: Discussionmentioning

confidence: 79%

“…We observed longer average distances among lineages in clade 3 compared to clades 1 and 2, which could be the result of accelerated rates of evolution or insufficient sampling within the clade (Figure b). Our approach allowed us to resolve the internal structure of the phylogenetic clusters, a main difference between our approach and those published previously (Ahmed et al., ; Schellenberg, Patterson, & Hill, ). Our results suggest that, as more genomes are analyzed, there is a possibility that additional clades of interest will be defined.…”

Section: Resultsmentioning

confidence: 99%

“…The strains JCP8481A and JCP8481B that get assigned to clade A in Schellenberg et al. () (4 in Ahmed et al., ) seem to be incorrectly assigned. In our reconstruction, these strains are confidently assigned to clade 3A (see Figure a) (clade 3 in Ahmed et al., ).…”

Section: Discussionmentioning

confidence: 99%

“…Clades 1 and 2 defined here include isolates reported for clades 1 and 2 in Ahmed et al (2012) and clades C and B (respectively) reported by Schellenberg et al (2017). Our clade 3 corresponded to clades 3 and 4 in Ahmed et al (2012) and clades D and A (respectively) reported by Schellenberg et al (2017). The reason to consider previously reported clades 3 and 4 (as in Ahmed et al) in a single group is purely operational, and we attempt not to bias our gene enrichment analysis by comparing clades with much fewer lineages.…”

Section: Discussionmentioning

confidence: 99%

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Focusing the diversity of Gardnerella vaginalis through the lens of ecotypes

Cornejo

Hickey

Suzuki

et al. 2017

Evolutionary Applications

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Gardnerella vaginalis has long been associated with bacterial vaginosis, a condition that increases the risk of women to preterm birth, sexually transmitted infections, and other adverse sequelae. However, G. vaginalis is also commonly found in healthy asymptomatic women of all ages. This raises the question if genetic differences among strains might distinguish potentially pathogenic from commensal strains. To disentangle the diversity of G. vaginalis, we invoked the concept of ecotypes—lineages of genetically and ecologically distinct strains within a named species—to better understand their evolutionary history and identify functional characteristics. We compared the genomes of G. vaginalis to six species in the closely related Bifidobacterium genus and found that G. vaginalis has a large accessory genome relative to Bifidobacterium, including many unique genes possibly involved in metabolism, drug resistance, and virulence. We then performed a comparative genomic analysis of 35 strains of G. vaginalis to infer a phylogeny based on the combined analysis of the core genome, using nucleotide substitution models, and the accessory genome, using gene gain/loss models. With the inferred tree topology, we performed comparisons of functional gene content among lineages that diverged at varying depths in the phylogeny and found significant differences in the representation of genes putatively involved in pathogenicity. Our functional enrichment analysis suggests that some lineages of G. vaginalis may possess enhanced pathogenic capabilities, including genes involved in mucus degradation like sialidases, while others may be commensal strains, lacking many of these pathogenic capabilities. The combined phylogenetic evidence and functional enrichment analysis allowed us to identify distinct ecotypes that have evolved in G. vaginalis as the result of the differential gene gain/loss for specific functions, including the capability to cause disease. We finally discuss how this analysis framework could be used to gain insight into the etiology of bacterial vaginosis and improve diagnosis.

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Section: Discussionmentioning

confidence: 66%

“…() and clades C and B (respectively) reported by Schellenberg et al. (). Our clade 3 corresponded to clades 3 and 4 in Ahmed et al.…”

Section: Discussionmentioning

confidence: 79%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Focusing the diversity of Gardnerella vaginalis through the lens of ecotypes

Cornejo

Hickey

Suzuki

et al. 2017

Evolutionary Applications

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Weitere medizinisch bedeutsame Bakterien

Hornef¹

2020

Medizinische Mikrobiologie Und Infektiologie

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A Generalist Lifestyle Allows Rare Gardnerella spp. to Persist at Low Levels in the Vaginal Microbiome

2020

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Gardnerella spp. are considered a hallmark of bacterial vaginosis, a dysbiosis of the vaginal microbiome. There are four cpn60 sequence-based subgroups within the genus (A, B, C and D), and thirteen genome species have been defined recently. Gardnerella spp. co-occur in the vaginal microbiome with varying abundance, and these patterns are shaped by a resourcedependent, exploitative competition, which affects the growth rate of subgroups A, B and C negatively. The growth rate of rarely abundant subgroup D, however, increases with the increasing number of competitors, negatively affecting the growth rate of others. We hypothesized that a nutritional generalist lifestyle and minimal niche overlap with the other more abundant Gardnerella spp. facilitate the maintenance of subgroup D in the vaginal microbiome through negative frequency-dependent selection. Using 40 whole-genome sequences from isolates representing all four subgroups, we found that they could be distinguished based on the content of their predicted proteomes. Proteins associated with carbohydrate and amino acid uptake and metabolism were significant contributors to the separation of subgroups. Subgroup D isolates had significantly more of their proteins assigned to amino acid metabolism than the other subgroups. Subgroup D isolates were also significantly different from others in terms of number and type of carbon sources utilized in a phenotypic assay, while the other three could not be distinguished. Overall, the results suggest that a generalist lifestyle and lack of niche overlap with other Gardnerella spp. leads to subgroup D being favoured by negative frequency-dependent selection in the vaginal microbiome.

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Gardnerella vaginalis diversity and ecology in relation to vaginal symptoms

Cited by 42 publications

References 67 publications

Focusing the diversity of Gardnerella vaginalis through the lens of ecotypes

Focusing the diversity of Gardnerella vaginalis through the lens of ecotypes

Weitere medizinisch bedeutsame Bakterien

A Generalist Lifestyle Allows Rare Gardnerella spp. to Persist at Low Levels in the Vaginal Microbiome

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