Volume 6 Issue 7, July 2021

A high-fat diet causes gut microbiota dysbiosis and depletion of the microbial metabolite indole-3-acetic acid in a murine model, resulting in decreased antibiotic efficacy against bacterial infections.

Some gut bacterial pathogens can escape antibody-mediated immunity by changing surface-exposed antigens, such as O-antigens. But by using vaccines targeting specific O-antigens to induce immunoglobulin A responses in the gut, such pathogens can also be directed to evolve towards expressing O-antigen variants that impair gut colonization.

The spike protein of SARS-CoV-2 harbours a cleavage motif for host cell proteases that is not found in closely related viruses. Peacock and colleagues show that this motif allows the virus to evade innate antiviral defences and is required for transmission.

Salmonella mutants with reduced ability to colonize the mouse gut and cause disease are selected for by vaccine-induced intestinal antibody responses in mice.

A piggyBac transposon mutagenesis screen identifies the long non-coding RNA, DINOR, in the human fungal pathogen Candida auris. DINOR is a virulence factor and regulates fungal stress responses and filamentation.

Arabidopsis thaliana plants lacking the rbohD gene, which encodes the NADPH oxidase RBOHD, have an altered leaf microbiome including an enrichment of opportunistic pathogens, indicating that RBOHD is essential for maintaining leaf microbiota homeostasis.

Fetal meconium does not have a detectable microbiota, as shown using 16S rRNA sequencing and culture of rectal swabs collected during elective breech caesarean sections without labour and before antibiotics, indicating that colonization occurs during and after birth.

High-fat diet decreases antibiotic efficacy in a mouse model via an altered gut microbiota and decreased indole-3-acetic acid, which potentially converts tolerant bacterial cells into susceptible metabolically active cells.

Using microcosms, stable isotope probing, genome-resolved metagenomics and NanoSIMS, the authors identify diverse bacterial taxa that can degrade extracellular DNA in marine sediments, including ‘Candidatus Izemoplasma’, which encode numerous extracellular nucleases.

Efficient transmission of SARS-CoV-2 among infected ferrets requires a functional furin cleavage site in the SARS-CoV-2 spike protein.

A two-protein module mediates Vibrio cholerae cell curvature and is sufficient to curve other Gram-negative bacteria. This module functions independently of cytoskeleton-directed machineries by directly binding to the cell wall.

Cryo-electron microscopy analyses show how Lassa and Machupo virus Z proteins bind the viral L polymerase and how this inhibits virus replication.

IFI16 enhances the type I IFN response to inhibit influenza virus replication by two mechanisms: it directly binds viral RNA to promote RIG-I activation and upregulates RIG-I expression via recruiting RNA polymerase II and binding to the RIG-I promoter.

Resolving widespread incomplete and uneven archaeal classifications is achieved by a rank-normalized genome-based taxonomy.

Almost 190,000 draft-quality DNA virus genomes are recovered by mining more than 11,000 deposited human stool metagenomes to improve resources for understanding the human gut virome.