<i>Spirochaeta</i>

The intestinal tracts of termites are abundantly colonized by a diverse assemblage of spirochetes. Most of them belong to ‘termite cluster I’, a monophyletic group within the radiation of the genus Treponema that occurs exclusively in termite guts. Phylogenomic analysis revealed that members of the genus Treponema are extremely diverse and represent two separate, family-level lineages: the Treponemataceae sensu stricto, which comprise the majority of the validly described Treponema species, and a second lineage that comprises the remaining members of the genus Treponema , including all members of ‘termite cluster I’ from termites and the recently isolated Breznakiella homolactica from cockroaches. Here, we present the formal description of Breznakiellaceae fam. nov. and of the new genera required to accommodate the misplaced Treponema species in the new family as new combinations (Leadbettera azotonutricia, Gracilinema caldarium, Helmutkoenigia isoptericolens and Zuelzera stenostrepta). To avoid paraphyly of Treponemataceae , we propose Rectinemataceae fam. nov. to include the genus Rectinema .

show abstract

“…The characteristics of the species are as given in the descriptions of the type strain [30–32], summarized by [33].…”

Section: Description Of Zuelzera Stenostrepta Comb Novmentioning

confidence: 99%

A new family for ‘termite gut treponemes’: description of Breznakiellaceae fam. nov., Gracilinema caldarium gen. nov., comb. nov., Leadbettera azotonutricia gen. nov., comb. nov., Helmutkoenigia isoptericolens gen. nov., comb. nov., and Zuelzera stenostrepta gen. nov., comb. nov., and proposal of Rectinemataceae fam. nov.

Brune

Song

Oren

et al. 2022

International Journal of Systematic and Evolutionary Microbiology

Self Cite

View full text Add to dashboard Cite

show abstract

Giant Bacteria

Ionescu

Bižić

2019

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

For almost all bacteria, it is convenient to be very small, but a few highly specialist groups of bacteria have evolved to be orders of magnitude larger than ordinary bacteria. While some of these giant microbes are abnormally large in all dimensions, others are long and thin or consist of assemblages of multiple cells. These giant bacteria are spread across the domain Bacteria and have evolved multiple ways to combat diffusion constrains. Giant bacteria often thrive in nutrient and carbon‐rich environments and/or in steep redox gradients. Genomically, giant bacteria seem all to be polyploid, that is containing multiple copies of their genome. Giant bacteria have been described throughout the history of microbial research but only some of them can be traced in current taxonomy and are being actively studied. Therefore, it is likely there are other giant bacteria in nature, awaiting to be explored. Key Concepts Growth and activity of giant bacteria are expected to be constrained by a combination of diffusion of nutrients into the cells as well as intracellular trafficking of solutes by diffusion. Giant bacteria can be divided into ‘truly’ giant, consisting of abnormally large cells on all dimensions, or ‘pseudo‐giant’ consisting of cells abnormally large on one axis or multicellular assemblages of bacteria. ‘Pseudo‐giant’ bacteria may not face the same diffusion limitations as ‘truly’ giant bacteria. ‘Truly’ giant bacteria likely ‘resolve’ diffusion constrains by one or more methods including, minimising cytoplasmic space by intracellular (pseudo)compartmentalisation, storage vacuoles, rapid swimming. Giant bacteria often grow in carbon‐ and nutrient‐rich environments and/or in steep redox gradients, thus additionally minimising diffusion‐related constraints. Current knowledge suggests that all giant bacteria contain multiple copies of their genomes being oligoploid (3–10 copies) or polyploid (10–1000s of copies). Gigantism in bacteria occurs in multiple phylogenetic lineages covering both Gram‐negative and Gram‐positive taxa. Early descriptions of giant bacteria suggest that the currently studied taxa do not encompass the entire diversity of abnormally large bacteria.

show abstract

Subversion of the immune response of human pathogenic spirochetes

Huang

Chen

Xie

et al. 2022

Clinical Laboratory Analysis

View full text Add to dashboard Cite

Spirochetes are prokaryotic microorganisms that are slender, flexible, spiral-shaped, and highly motile. They are widely distributed in nature and are commonly found in water, soil, and other putrefactive organic matter, as well as in the human mouth and animal body.Spirochetes are mainly divided into five genera of Spirochaetaceae based on differences in size, regularity, space structure, physiological characteristics, and host cells. There are namely Cristispira, 1

show abstract

Spirochaeta

Cited by 3 publications

References 42 publications

Giant Bacteria

Subversion of the immune response of human pathogenic spirochetes

Contact Info

Product

Resources

About