Using Genomics to Decipher the Enigmatic Properties and Survival Adaptation of Candidate Phyla Radiation.

Microbial ecology is a critical field for understanding the composition, diversity, and functions of microorganisms in various environmental and health-related processes. The discovery of Candidate Phyla Radiation (CPR) through culture-independent methods has introduced a new division of microbes characterized by a symbiotic/parasitic lifestyle, small cell size, and small genome. Despite being poorly understood, CPRs have garnered significant attention in recent years due to their widespread detection in a variety of environmental and clinical samples.

Candidate Phyla Radiation, an Underappreciated Division of the Human Microbiome, and Its Impact on Health and Disease.

Candidate phyla radiation (CPR) is an emerging division of the bacterial domain within the human microbiota. Still poorly known, these microorganisms were first described in the environment in 1981 as "ultramicrobacteria" with a cell volume under 0.1 μm and were first associated with the human oral microbiota in 2007.

New Beta-lactamases in Candidate Phyla Radiation: Owning Pleiotropic Enzymes Is a Smart Paradigm for Microorganisms with a Reduced Genome.

The increased exploitation of microbial sequencing methods has shed light on the high diversity of new microorganisms named Candidate Phyla Radiation (CPR). CPR are mainly detected via 16S rRNA/metabarcoding analyses or metagenomics and are found to be abundant in all environments and present in different human microbiomes. These microbes, characterized by their symbiotic/epiparasitic lifestyle with bacteria, are directly exposed to competition with other microorganisms sharing the same ecological niche.

Reverse Genomics: Design of Universal Epitope Sets to Isolate All Members from the Human Oral Cavity.

Microorganisms not yet cultured represent a large proportion of the microbes described to date. Progress in sequencing and metagenomic tools continues to increase microbial diversity without providing information on their physiological and pathophysiological characteristics, such as the recent discovery of enigmatic microbes belonging to Candidate Phyla Radiation (CPR). Reverse genomics is a recent technique allowing co-cultivation of a few CPR members, affiliated to the phylum, based on the analysis of their already-available genomes.

Adapted Protocol for Cocultivation: Two New Members Join the Club of Candidate Phyla Radiation.

The growing application of metagenomics to different ecological and microbiome niches in recent years has enhanced our knowledge of global microbial biodiversity. Among these abundant and widespread microbes, the candidate phyla radiation (CPR) group has been recognized as representing a large proportion of the microbial kingdom (>26%). CPR are characterized by their obligate symbiotic or exoparasitic activity with other microbial hosts, mainly bacteria.

Small and Equipped: the Rich Repertoire of Antibiotic Resistance Genes in Candidate Phyla Radiation Genomes.

Microbes belonging to Candidate Phyla Radiation (CPR) have joined the tree of life as a new branch, thanks to the intensive application of metagenomics and sequencing technologies. CPR have been eventually identified by 16S rRNA analysis, and they represent more than 26% of microbial diversity. Despite their ultrasmall size, reduced genome, and metabolic pathways which mainly depend on exosymbiotic or exoparasitic relationships with the bacterial host, CPR microbes were found to be abundant in almost all environments.

Rhizomal Reclassification of Living Organisms.

Living organisms interact with each other during their lifetime, leading to genomes rearrangement and sequences transfer. These well-known phenomena give these organisms mosaic genomes, which challenge their classification. Moreover, many findings occurred between the IXXth and XXIst century, especially the discovery of giant viruses and candidate phyla radiation (CPR).