News & Views in 2017

Bacterial biofilms fabricate an extracellular amyloid fibre network that intimately links cells together and inhibits the ability of bacteriophages to penetrate the biofilm.

The development of tools to accelerate identification of causal microorganisms is crucial, and advances in microbial culture, bioinformatics and animal experimentation are currently driving these discoveries.

The mechanisms involved in controlling Candida albicans at mucosal sites are not fully understood. Recent work identifies the EphA2 on epithelial cells as a fungal β-glucan receptor that is critical for mediating protective immunity during oral candidiasis.

The incorporation of additional gene circuits into hosts can often lead to unpredicted and undesirable behaviours. Recent work has developed a modelling framework that accounts for host–circuit interactions and can predict a variety of phenotypes at both single-cell and population levels.

The use of levulinic acid in bioconversion strategies has been limited by the lack of information on the pathways used by microorganisms to degrade it. Now, functional genomics reveals the essential steps for utilization of levulinic acid in Pseudomonas putida.

Recent work finds that reactive oxygen species are generated in cells starved for the nucleobase thymine and contribute to DNA-destructive “thymineless death” mechanisms, which underlie the activities of many drugs, including trimethoprim and sulfa-based antibiotics. Such mechanisms may also apply to cells across the tree of life.

Two studies identify circulating monocytes as the primary cellular target of Zika virus infection in human blood. Monocytes are an ideal target as they have the potential to be used as a Trojan horse to infiltrate immune-sheltered tissues, including placenta, testes and the brain, to spread Zika virus.

The Uncultivated Bacteria and Archaea dataset is a foundational collection of 7,903 genomes from uncultivated microorganisms. It highlights how microbial diversity is readily recovered using current tools and existing metagenomic datasets to help piece together the tree of life.

The Streptococcus pyogenes surface M protein is a critical multifunctional virulence factor. Recent work sheds light on a new unexpected function of the M protein in activating the host inflammasome to induce macrophage cell death and promote infection.

The goal of malaria eradication is threatened by drug resistance. Now, two studies characterize Plasmodium falciparum PKG inhibitors and hexahydroquinolines as antimalarial compounds that could block transmission and help mitigate the risk of parasite escape via drug resistance.

Influenza B virus causes substantial illness globally, particularly in children. Treatment options are limited, as the most widely used antiviral drug appears to be less effective than against influenza A. A new antibody targeting the influenza B neuraminidase shows promise in mice as a therapeutic option.

A newly described plasmid, which encodes proteins facilitating its packaging and cell-to-cell transfer via membrane vesicles, challenges the way we think about the delineation of viruses, plasmids and extracellular vesicles.

The study of phages that pose a threat to the cheese industry, which enabled the original demonstration that CRISPR–Cas systems work as adaptive immune systems in bacteria, now leads to the identification of a new anti-CRISPR that inhibits Cas9 from Streptococcus pyogenes.

Proteomics analyses reveal how the long-term coexistence of the marine picocyanobacterium Synechococcus and the heterotroph Ruegeria pomeroyi, of the globally abundant marine Roseobacter group, is based on the mutual and beneficial recycling of inorganic and organic nitrogen compounds.

The 2013–2016 West African Ebola virus outbreak evidenced that the virus can persist in survivors long-term, leading to sequelae and risks of new transmission chains. Ebola virus has now been shown to behave similarly in rhesus macaques, enabling their use to study persistence and intervention strategies.

Structural analyses of the type IV coupling protein of the Dot/Icm type IV secretion system from Legionella pneumophila reveal how this platform recruits a plethora of substrates for translocation.

The discovery and genomic characterization of a new group of extreme halophilic methanogens sheds light on the origin of methanogenesis and the evolution of the Haloarchaea.

Co-culture of bacterial cells engineered with quorum-sensing and self-lysis circuits allows coupled oscillatory dynamics and stable states, opening the way to engineered microbial ecosystems with targeted dynamics and extending gene circuits to the ecosystem level.

Nitric oxide synthase has long been associated with control of Mycobacterium tuberculosis infection. However, new work reveals that instead of directing an antibacterial killing response, nitric oxide is critical for restraining granulocytic inflammation, which can provide a nutrient-rich niche for increased bacterial growth.

Coenzymes serve as the catalytic core in many metabolic reactions, but despite their extensive use and intrinsic chemical reactivity, they are remarkably stable.