In PLOS Pathogens, researchers from Boston College describe experiments done by pairing transposon insertion mutagenesis with sequencing to profile genes involved in sensitivity to the antibiotic daptomycin in two strains of the bacterial pathogen Streptococcus pneumoniae. When it used Tn-Seq to look at TIGR4 and Taiwan-19F strain growth in the presence or absence of daptomycin, the team saw considerable wiggle room in the repertoire of genes each strain used to respond to daptomycin-related stress. The analysis also made it possible to characterize essential and conditionally important genes in the S. pneumoniae pan-genome.
A team from the Institute of Tropical Medicine in Belgium takes a look at the proteome of Treponema pallidum sub-species pallidum, the pathogen behind syphilis, for a paper in PLOS Neglected Tropical Diseases. Using tandem mass spectrometry, the researchers analyzed a T. pallidum ssp. pallidum from rabbits, uncovering more than 6,000 peptides comprising 557 proteins. The set, which included just over half of the proteins believed to make up the pathogen's complete proteome, contained more than 100 proteins had not been directly detected in the past.
Enhanced expression of a microRNA called miR-9 seems to be at the heart of a miRNA signature that distinguishes ovarian clear cell carcinoma from the high-grade serous carcinoma subtype of ovarian cancer, according to a study appearing in PLOS One. Japanese researchers relied on array-based strategies to profile the expression of 88 miRNAs in tumor samples from a dozen individuals with high-grade serous carcinoma and 15 ovarian clear cell carcinoma cases. They found that inhibiting miR-9, one of the five miRNAs with higher expression in ovarian clear cell carcinoma, impaired the invasiveness of ovarian cancer cell line assays.