Volume 3 Issue 5, May 2018

Faecal microbiota richness is considered a hallmark of gut health and stability. However, in healthy hosts, richness would primarily reflect the stage of ecosystem development through the gut, rather than community resilience. This Comment discusses the need to rethink microbiome biomarkers in the context of gut ecology.

A study of blood-feeding female sand flies has shown how successive blood meals amplify Leishmania infections in the vector’s gut and enhance transmission of the tropical disease leishmaniasis.

Topical administration of aminoglycoside antibiotics has been shown to induce expression of interferon-stimulated genes in dendritic cells, inducing an antiviral state in the vaginal and lung mucosa that increases resistance to infection with herpes simplex virus 1, influenza and Zika viruses.

The bacterial pathogen Staphylococcus aureus secretes a high-affinity insulin-binding protein that mediates insulin resistance, a major driver of obesity and type 2 diabetes, in a mouse model of infection.

Bacteria encode many strategies to prevent or escape infection. Through the analysis of metagenomic dark matter, several novel defence systems were identified, some of which were engineered and characterized in vivo, showing that they provide resistance against viruses and plasmids.

Using a combination of remote-sensing technologies, lipidomics and gene-based biomarkers, the authors demonstrate a coupling between viral infection of an Emiliania huxleyi bloom and the export of organic and inorganic carbon from the photic zone.

Sand flies acquire Leishmania during blood meals. Subsequent blood meals, even from uninfected hosts, trigger dedifferentiation of non-replicating metacyclic promastigotes to a replicative form, termed the retroleptomonad promastigote, which amplifies parasite numbers in the flies.

This study describes the development of a primate model for Crimean–Congo haemorrhagic fever, the first immunocompetent animal model, which will be instrumental in developing and testing medical countermeasures for this serious disease.

A transcriptional regulator in Acinetobacter baumannii controls a phenotypic switch between environmentally fit and in vivo virulent subpopulations.

Characterization of xylan utilization loci in the butyrate-producing Firmicute Roseburia intestinalis provides mechanistic insight into its growth on different xylan substrates and its ability to co-grow and compete with a xylan-degrading commensal from the Bacteroides genus.

Cryo-electron microscopy of a type II secretion system pilotin–secretin complex uncovers interactions involved in complex assembly.

A systematic analysis of viral protein phosphorylation elucidates the signalling network of the vaccinia virus F10 kinase and H1 phosphatase, identifying new functions for the reversible phosphorylation of the I7 protease and A7 transcription factor.

Splenic CD169⁺ macrophages serve as an intracellular reservoir for Streptococcus pneumoniae replication and are a target for cell-penetrant antibiotic therapy to prevent septicaemia.

Aminoglycoside antibiotics administered topically are shown to induce a Toll-like-receptor-3-dependent interferon response mediated by XCR1⁺ dendritic cells that is unrelated to effects on the microbiota and can confer an antiviral state to the vaginal mucosa.

The extracellular domain of the cell wall protein LtaS is an insulin-binding protein and mediates insulin resistance during Staphylococcus aureus infection.

The Pseudomonas aeruginosa effector TseT is loaded into the type VI secretion system (T6SS) by the chaperone TecT. Interactions between the T6SS needle-tip protein PAAR and TecT disrupt binding between TecT and its co-chaperone, co-TecT, and promote binding of TseT to PAAR.