Towards standardisation of naming novel prokaryotic taxa in the age of high-throughput microbiology

Microbial underdogs: exploring the significance of low-abundance commensals in host-microbe interactions

Our understanding of host-microbe interactions has broadened through numerous studies over the past decades. However, most investigations primarily focus on the dominant members within ecosystems while neglecting low-abundance microorganisms. Moreover, laboratory animals usually do not have microorganisms beyond bacteria. The phenotypes observed in laboratory animals, including the immune system, have displayed notable discrepancies when compared to real-world observations due to the diverse microbial community in natural environments. Interestingly, recent studies have unveiled the beneficial roles played by low-abundance microorganisms. Despite their rarity, these keystone taxa play a pivotal role in shaping the microbial composition and fulfilling specific functions in the host. Consequently, understanding low-abundance microorganisms has become imperative to unravel true commensalism. In this review, we provide a comprehensive overview of important findings on how low-abundance commensal microorganisms, including low-abundance bacteria, fungi, archaea, and protozoa, interact with the host and contribute to host phenotypes, with emphasis on the immune system. Indeed, low-abundance microorganisms play vital roles in the development of the host's immune system, influence disease status, and play a key role in shaping microbial communities in specific niches. Understanding the roles of low-abundance microbes is important and will lead to a better understanding of the true host-microbe relationships.

Bacterial nomenclature in the era of genomics

The remarkable success of taxonomic discovery, powered by culturomics, genomics and metagenomics, creates a pressing need for new bacterial names while holding a mirror up to the slow pace of change in bacterial nomenclature. Here, I take a fresh look at bacterial nomenclature, exploring how we might create a system fit for the age of genomics, playing to the strengths of current practice while minimizing difficulties. Adoption of linguistic pragmatism-obeying the rules while treating recommendations as merely optional-will make it easier to create names derived from descriptions, from people or places or even arbitrarily. Simpler protologues and a relaxed approach to recommendations will also remove much of the need for expert linguistic quality control. Automated computer-based approaches will allow names to be created en masse before they are needed while also relieving microbiologists of the need for competence in Latin. The result will be a system that is accessible, inclusive and digital, while also fully capable of naming the unnamed millions of bacteria.

The status Candidatus for uncultured taxa of Bacteria and Archaea: SWOT analysis

The status Candidatus was introduced to bacterial taxonomy in the 1990s to accommodate uncultured taxa defined by analyses of DNA sequences. Here I review the strengths, weaknesses, opportunities and threats (SWOT) associated with the status Candidatus in the light of a quarter century of use, twinned with recent developments in bacterial taxonomy and sequence-based taxonomic discovery. Despite ambiguities as to its scope, philosophical objections to its use and practical problems in implementation, the status Candidatus has now been applied to over 1000 taxa and has been widely adopted by journals and databases. Although lacking priority under the International Code for Nomenclature of Prokaryotes, many Candidatus names have already achieved de facto standing in the academic literature and in databases via description of a taxon in a peer-reviewed publication, alongside deposition of a genome sequence and there is a clear path to valid publication of such names on culture. Continued and increased use of Candidatus names provides an alternative to the potential upheaval that might accompany creation of a new additional code of nomenclature and provides a ready solution to the urgent challenge of naming many thousands of newly discovered but uncultured species.