Microbiology Research News and Articles - by David Ojcius

Rhizopus arrhizus emerges as a key fungal driver of metabolic steatotic liver cancer. Its conditioned medium boosts proliferation of human tumor cells, while kynurenic acid produced by the fungus promotes tumor growth in mice. Kynurenic acid binds IQGAP1 and activates MAPK signaling, revealing a pathogenic host–fungus interaction that may be therapeutically targeted to suppress disease progression.

Plasma gelsolin reduces acute inflammation and fungal burden in a 24‑hour mouse model of candidemia. Treatment lowers inflammatory gene expression, decreases renal and pulmonary injury, and improves fungal clearance. In human monocytes, plasma gelsolin boosts fungal uptake, enhances intracellular killing, and modulates reactive radical production without direct candidacidal activity.

Cryo‑electron tomography of native and antibiotic‑perturbed Mycoplasma pneumoniae cells yields 140 in‑cell maps capturing translation initiation, elongation, and recycling. The study visualizes transcription‑translation assemblies, proposes a threading‑based reinitiation mechanism, and provides structural evidence for a supercomplex coordinating transcription, translation, and membrane attachment

Cryo‑electron tomography of Mycoplasma pneumoniae reveals a surface complex combining the conserved Sec‑translocon with a dome‑like assembly formed by three previously uncharacterized Mdps. Integrative proteomics and structural modeling show Mdps resemble PrsA‑like foldases, with Mdp444 retaining catalytic activity. The study provides sub‑nanometer maps of SecA‑mediated translocation coordinated with extracellular protein folding.

Migratory locust eggs emit the microbial volatile 2,4,6‑trimethylpyridine, attracting conspecific females through LmOR34 and LmOR36 to synchronize oviposition. The compound is produced by Enterobacter roggenkampii via lysine degradation, and its loss disrupts attraction. Beyond coordination, 2,4,6‑trimethylpyridine repels soil predators, revealing a dual reproductive and defensive signaling system.

Clostridium immunis protects mice from obesity by secreting a phosphocholine‑modified exopolysaccharide that lowers IL‑22 in the intestine and visceral fat, boosting metabolic activity in adipose tissue. Mutant studies show phosphocholine is essential. Humans with obesity show reduced phosphocholine‑gene abundance, highlighting a translatable strategy to reduce visceral fat.