A team from the US and Guatemala explore the genetic diversity of the Chagas disease-causing parasite Trypanosoma cruzi in Central America for a paper appearing in PLOS Neglected Tropical Diseases. The researchers used 18S ribosomal RNA sequencing to identify discrete typing units in T. cruzi parasites carried by the kissing bug vector Triatoma dimidiata, using more than 300 samples from Mexico, Central America, or Colombia. The results suggest that "parasites are moving among vectors/hosts and ecotypes," the authors note, arguing that "a comprehensive approach, such as the Ecohealth approach that makes houses refractory to the vectors will be needed to successfully halt transmission of Chagas disease."
Researchers from Poland and France consider the Chlamydia species found in and on captive and free-living turtles in PLOS One. Using a combination of Chlamydiaceae-specific PCR, 16S rRNA sequencing, and 23S rRNA sequencing, the team assessed pharyngeal swab, cloacal swab, and tissue samples from 204 turtles and tortoises from 11 species, genotyping Chlamydiaceae species when present. Nearly 29 percent of captive turtles or tortoises and more than 18 percent of their wild counterparts tested positive for one or more Chlamydiaceae species, they report, including almost two-thirds of species from the Testudo tortoise genus.
In PLOS Genetics, a University of Chicago-led team reports on findings from an expression search for breast cancer risk genes. With the help of software that had been trained using transcriptome and genotyping data for hundreds of individuals with or without major depressive disorder, the researchers analyzed available genome-wide association study data for more than 8,600 breast cancer cases and nearly 8,100 unaffected controls, searching for genetically-predicted shifts in breast cancer-associated genes. In particular, their analysis pointed to apparent ties between TP53INP2 and estrogen receptor-negative breast cancer in individuals of European, African, or Asian ancestry.