In PLOS Pathogens, researchers from Tufts University and elsewhere present results from a transposon insertion sequencing-based screen of the Lyme disease-causing pathogen Borrelia burgdorferi. Through high-throughput sequencing on a transposon library of B. burgdorferi representatives exposed to reactive oxygen and nitrogen species, the team searched for genes involved in oxidative stress response in B. burgdorferi, which is exposed to oxidative species in tick vectors and the vertebrates they infect. The search led to 66 candidate genes, including genes coding for components of DNA repair, transport, and inner cell membrane pathways.
A team from the US and Peru studied the range of animals that were bitten by Anopheles darling mosquitoes in the Amazon region of Peru. As they report in PLOS Neglected Tropical Diseases, the researchers used PCR and targeted sequencing to assess blood meal samples from mosquitoes at three Amazonian sites between 2013 and 2015. While humans appeared to be the most common mosquito meal, they found that nearly one-third of mosquitoes tested also consumed blood from dogs, rats, livestock animals, and a wide range of birds.
New World populations of the human pathogen Helicobacter pylori, best known for causing stomach ulcers, appear to have descended from the strains carried to the region by European settlers and slaves from Africa, according to a PLOS Genetics paper. An international research team performed genome sequencing on more than 400 H. pylori isolates from around the world, uncovering seven Old World and five New World populations of the bug. Because some New World strains contained sequences resembling European and African H. pylori sequences, the researchers suspect that past human migration patterns are reflected in present-day pathogens. Our sister publication GenomeWeb has more on the study, here.