In PLOS Genetics, researchers from the University of Edinburgh and David Geffen School of Medicine outline findings from a genome-wide association study focused on epigenetic age acceleration — DNA methylation-based aging that outpaces an individual's chronological age. After looking at epigenetic age acceleration patterns in 5,100 genotyped and DNA methylation-profiled participants in a Scottish family health study called Generation Scotland, the team did a GWAS for 13,493 individuals of European ancestry from a dozen cohorts, focusing on the "Horvath" and "Hannum" measures of epigenetic age acceleration. The search led to 10 variants with apparent ties to the Horvath measure and another variant associated with Hannum epigenetic age acceleration, the authors report, though none of the risk variants carried over from one epigenetic age acceleration measure to the next.
A University of Vermont team takes a look at antimicrobial resistance genes found in food waste diversion or compost samples from a commercial poultry farm by metagenomic sequencing. As they report in PLOS One, the researchers did metagenomic sequencing on more than a dozen samples from an organic egg farm in northeastern Vermont, including on-farm food scrap, compost, worm cast, or egg samples and samples from off-farm sites used to produce post-consumer food waste feed. From these sequences, they narrowed in on 50 antimicrobial resistance genes and 54 virulence gene sequences, along with 500 bacterial species or sub-species, though the microbial representatives appeared to be distinct in samples originating on or off the farm. "[Antimicrobial resistance gene] sequences related to aminoglycoside, tetracycline, and macrolide resistance were most prominent," the authors report, "while most virulence gene sequences were related to transposon or integron activity.
For their part, researchers from Harvard Medical School, Brigham and Women's Hospital, and elsewhere search for drug targets in Staphylococcus aureus for a paper appearing in PLOS Pathogens. Using transposon sequencing (Tn-Seq), the team characterized the genes required for survival in S. aureus strains before or after treatment with the antibiotic daptomycin. In the untreated strains, the authors saw somewhat variable fitness genes and pathways, though specific pathways remained important across strains following daptomycin treatment. Such findings point to the possibility of "core vulnerabilities that can be exploited to re-sensitize daptomycin-non-susceptible isolates," they write, noting that "daptomycin vulnerabilities and resistance mechanisms support a mode of action with wide-ranging effects on the cell envelope and cell division."