Researchers from Tufts University, Texas A&M University, and elsewhere describe genes that help Lyme disease-causing Borrelia burgdorferi bacteria survive in Ixodes ticks for a PLOS Pathogens paper. Using transposon insertion sequencing (Tn-seq), the team screened for B. burgdorferi genes that dialed down the pathogen's fitness in the tick, uncovering 102 known or uncharacterized genes leading to decreased fitness or loss-of-function in the tick. In their follow-up experiments, the authors found that one of the uncharacterized genes in this set seemed to contribute to oxidative stress resistance for pathogens in the tick vector. They argue that the "application of TN-seq to in vivo screening of B. burgdorferi in its natural vector is a powerful tool that can be used to address many different aspects of the host-pathogen interaction."
In PLOS Neglected Tropical Diseases, a team from Brazil and France present evidence suggesting multiple Chikungunya virus (CHIKV) genotypes contributed to a recent outbreak of the disease in Brazil's northeast. The researchers used an in-house, whole-genome CHIKV amplicon sequencing pipeline to assess eight clinical samples from an outbreak in 2015 and early 2016, identifying cases of co-infection with isolates from an Asian/Caribbean genotype and a genotype known as the African ECSA. "Our results demonstrate that both Asian/Caribbean and ECSA genotypes expanded their ranges," they write, "reaching co-circulation in the Northeast region of Brazil."
For a paper appearing in PLOS One, investigators at Radboud University Medical Center, Utrecht University, University College London, and elsewhere present a collection of suspected ciliary genes, including 285 new candidate cilia genes gleaned from a combination of genomic, proteomic, transcriptomic, and other data. The resulting resource, known as CiliaCarta, currently contains nearly 1,000 potential cilia genes, the team says. When they took a closer look at a subset of three dozen potential cilia genes with experiments in mouse, nematode, or nematode models, the investigators shored up apparent ciliary roles for proteins encoded by 24 of the genes. They suggest that CiliaCarta "can be used to objectively prioritize candidate genes in whole exome or genome sequencing of ciliopathy patients."