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This Week in PNAS: Feb 12, 2019

Researchers from the US, Japan, and Sierra Leone present findings from a blood plasma lipidome analysis of individuals infected with the Ebola virus during an outbreak in 2014 to 2016, where they compared lipids circulating in the blood of those who did or did not survive the disease. Based on plasma liquid chromatography tandem mass spectrometry profiles for sequential samples collected from 11 Ebola survivors, nine individuals who died of Ebola virus disease, and seven healthy volunteers, the team quantified more than 400 lipid from four main categories, including lipids with potential ties to disease outcome. "Specific changes in the lipidome suggested contributions from extracellular vesicles, viremia, liver dysfunction, apoptosis, autophagy, and general critical illness," the authors write, "and we identified possible targets for therapies enhancing [Ebola virus disease] survival." 

A team from Australia, Taiwan, and the UK explores metabolic adaptation by the bacterial pathogen Staphylococcus aureus to dodge the host innate immune system and last-line antibiotics such as daptomycin, which targets the bacterial cell membrane. Using whole-genome sequencing, treatment assays, thin-layer chromatography of lipids, liquid chromatography-mass spectrometry, and other approaches, the researchers assessed samples from nine daptomycin-treated individuals with S. aureus bloodstream infections, uncovering resistance-related point mutations in the cardiolipin synthase enzyme gene cls2 that appear to alter bacterial membrane features. These and other findings "highlight the importance of bacterial membrane lipid adaptation in bacterial pathogenesis," they report, "and provide crucial insights into potentially novel therapeutic targeting."

Researchers at the University of Texas Health Science Center, the University of California, Riverside, and elsewhere describe genome organization features in the malaria-causing parasite Plasmodium falciparum and other intracellular parasites in the Apicomplexa phylum. The team came up with three-dimensional genome models for five species in the Plasmodium genus — along with the babesiosis and toxoplasmosis culprits Babesia microti and Toxoplasma gondii — with in situ Hi-C experiments, available genome and gene expression data, improved genome assemblies, and other approaches. For example, the authors note that "the two most pathogenic human malaria parasites shared unique features in the organization of gene families involved in antigenic variation and immune escape," among other genome structure differences relative to less virulent parasites.