Reviews & Analysis

The biologically active form of vitamin B₁ is not required by Borrelia burgdorferi, the bacterium that causes Lyme disease, challenging the paradigm that this vitamin is essential for all living organisms.

Type VII protein secretion systems are most widely associated with virulence in bacterial pathogens. A new study reveals a type VII system-secreted nuclease toxin that specifically affects clonally unrelated strains, thus placing type VII secretion directly into the fray of microbial competition.

Bacterial infection of the bladder can lead to mucosal remodelling and increased predisposition to recurrent infection, changing the way we view host susceptibility and providing new opportunities to develop novel therapeutics.

The symbiosis between UCYN-A and haptophyte picoplankton plays a major role in oceanic nitrogen cycling. Though it bears some resemblance to freshwater examples, making it an interesting marine model, UCYN-A diversity means that many questions remain.

An effector protein secreted by the intracellular human pathogen Mycobacterium tuberculosis impairs antigen processing in targeted phagocytic cells, resulting in evasion from immune surveillance by a dedicated adaptive immune response.

Microorganisms produce antibiotics, which can exclude competitors, but bacteria typically only synthesize modest amounts of these compounds. New work suggests this may be an evolutionary strategy to balance the benefits of antimicrobial warfare against inadvertently providing help to resistant free-loaders.

Plasmids are well known for spreading antibiotic-resistance genes between bacterial strains. Recent experiments show that they can also act as catalysts for evolutionary innovation, promoting rapid evolution of novel antibiotic resistance.

Sequence variability in microbial surface proteins can be extensive in order to promote immune escape, but the changes must not interfere with the function of the protein. Structural analysis of a streptococcal protein now clarifies how an extremely variable region retains its ability to specifically bind its human target.

Viruses, once thought of only as purveyors of disease, take centre stage, from the human microbiome to the oceans, as archives of global diversity and drivers of biogeochemical cycles.

The number of ribosomal operons in bacterial genomes correlates with both growth rate and carbon use efficiency, likely via proteome allocation trade-offs, providing clues into how microbial communities are structured to make best use of available nutrients.

Structural determination of the secreted haem-binding protein from Candida albicans reveals a novel fold and haem coordination environment that facilitates the shuttling of the haem cofactor across the cell wall to the cell surface.

Technological breakthroughs in cryo-electron microscopy are allowing the capture of virus structures, leading to advances in the field of viral microbiology almost daily. An innovative structure–function study on Aichi virus reveals that novel entry mechanisms, yet undiscovered, may exist for non-enveloped viruses.

Optical and force nanoscopy enable visualization of intracellular and extracellular microbial structures with unprecedented resolution. This Review discusses the principles, advantages and limitations of the main optical and force nanoscopy techniques available.

The spirochaete flagella, unlike those of other bacteria, are located entirely within the periplasm of the bacteria. New work highlights another unique spirochaete characteristic — an unusual covalent linkage that mediates flagellar hook self-polymerization and is required for motility.

Regulation of transcriptional termination in archaea has remained a mystery. Now, a high-throughput RNA sequencing approach identifies multiple archaeal genes that contain consecutive terminators, suggesting new ways by which these microorganisms regulate transcription.

Metagenomic analysis of Antarctic sea-ice and brine reveals the presence of hgcAB-like genes in the microaerophilic marine bacterium Nitrospina. These are similar to ones responsible for mercury methylation in anaerobic microorganisms and provide a plausible mechanism for mercury methylation in oxic marine environments.

A new, publicly available, collection of cultured bacterial species from the mouse gut, the Mouse Intestinal Bacterial Collection, opens up opportunities for deepening microbiome research. Cultured isolates allow the functions of specific species and controlled consortia to be determined through in vitro experimentation.

Patients with atopic dermatitis have fundamentally different skin microbial populations compared with people with healthy skin. Bacteria associated with atopic dermatitis express genes for survival in dry conditions and for ammonia production, modulating the pH of this distinct environment and driving complex ecological interactions.

Accurate estimates of disease burden are possible by building high-resolution geographical models. However, novel pathogens such as Zika virus pose substantial challenges, requiring both new analytical techniques and, where possible, serological surveys.

Protein-synthesizing bacterial and archaeal cells can now be visualized by an adaptation of the BONCAT method, and sorted from complex samples for sequencing. A demonstration on the uncultivated, slow-growing methane-oxidizing consortia shows the high potential of this new method.