Volume 4 Issue 1, January 2019

The early identification of repetitive genomic loci in Haloferax species was instrumental in igniting interest in CRISPR–Cas systems. Now, work in this genus has revealed an important role of CRISPR–Cas in reducing an unusual form of inter-species archaeal mating that occurs by cell fusion.

Hydrolysis of phosphatidylcholine to choline was found to be catalysed by phospholipase D enzymes from diverse members of the gut microbiota, revealing a mechanism by which commensals obtain choline for subsequent production of disease-associated trimethylamine.

APOBEC3 restriction, known to inhibit retroviruses by interfering with genome replication and hypermutating viral DNA, targets the γ-herpesvirus Epstein–Barr virus and is antagonized by the viral BORF2 protein.

Streptococcus pneumoniae strains colonizing the nasopharynx use quorum sensing and fratricide to outcompete incoming strains, thereby retaining ownership of the host. This occurs via activation of the competence regulon, induction of lytic proteins, and turning the invader into a source of DNA for genetic exchange.

This Review Article describes how recent advances in viral genome sequencing and phylogenetics have enabled key issues associated with outbreak epidemiology to be more accurately addressed, and highlights the requirements and challenges for generating, sharing and using such data when tackling a viral outbreak.

Mosquitoes are responsible for transmission of important human diseases, including malaria, dengue and Zika. Here, Shaw and Catteruccia discuss how studying insect biology can inform the development of new control strategies against vector-borne disease.

This Review discusses the role of the gut, respiratory tract and vaginal microbiota in susceptibility and resistance to infectious diseases.

A Perspective discussing the factors that have contributed to the success and failure of point-of-care tests for resource-limited settings and the challenges and opportunities that exist for developing new infectious disease diagnostics.

Shotgun metagenomes recovered from a thermal gradient at a coal-seam fire site identified distinct microbial communities with smaller genomes and cell sizes and altered metabolic genes in higher-temperature soils.

A Streptococcus pneumoniae toxin, pneumolysin, binds to MRC-1 on phagocytes to dampen immune responses and promote infection.

One of the most potently neutralizing flavivirus-specific monoclonal antibodies ever isolated, WNV-86, targets an epitope in E domain II of the West Nile virus (WNV), preferentially recognizes mature virions lacking an uncleaved form of the prM chaperone protein and protects mice from lethal WNV challenge when administered two days after infection.

The ribonucleotide reductase large subunit of the Epstein–Barr virus, BORF2, inhibits the DNA cytosine deaminase activity of the host restriction factor APOBEC3B and sequesters it in perinuclear and cytoplasmic bodies, thus preserving viral genome integrity during lytic reactivation.

The characterization of the type IV CRISPR system from Aromatoleum aromaticum shows that Csf2 serves as a backbone to which Csf5, Csf3 and Csf1 bind to form CRISPR–ribonucleoprotein complexes. Csf5 (a Cas6 variant) generates CRISPR RNAs with short, 7 nucleotide 5′-repeat tags and stable 3′ hairpin structures.

Pseudomonas aeruginosa quorum-sensing signal N-(3-oxo-dodecanoyl) homoserine lactone alters host cell membranes and induces host cell death via ligand-independent immune receptor ligation.

Development of a structure-based method to predict potential ARDs present in human metagenomes indicates that resistance genes are rarely transferred within the human gut, and that individuals can be clustered into resistotypes.

Structures of three enterovirus D68 capsid states and two monoclonal antibodies provide a molecular explanation for the transition of picornavirus capsid conformations and reveal distinct mechanisms for viral neutralization.

A Legionella pneumophila effector, MavC, mediates ubiquitination through a transglutamination reaction and targets host UBE2N to inhibit immune signalling during infection.

The manipulation of expression of PfAP2-G, the master regulator of gametocytogenesis in malaria parasites, reveals that in addition to the canonical next cycle conversion route, sexual conversion can occur without additional replication (that is, within the same cycle).

Phospholipase Ds (PLDs) transform phosphatidylcholine to choline, which can then be converted to disease-associated trimethylamine. Here, PLDs are identified in gut bacteria that support growth of other bacteria and are potential therapeutic targets.

The E3 ligase TRIM43 ubiquitinates the centrosomal protein pericentrin, targeting it for proteasomal degradation, leading to alterations of the nuclear lamina that repress active viral chromatin states of a range of herpesviruses.

A combination of genome sequencing of environmental archaeal isolates and experimental mating between Haloferax volcanii and Haloferax mediterranei shows that inter-species mating can induce the acquisition of CRISPR spacers, which modulate speciation.

Neutralizing murine monoclonal antibodies against the Eeastern equine encephalitis virus target the E2 glycoprotein, block infection at a post-attachment stage by inhibiting viral membrane fusion and protect mice from lethal challenge.

Resident Streptococcus pneumoniae colonizers persist in hosts by outcompeting incoming strains through the action of a quorum-regulated Com regulon.