Development of an inducer-free, virulence gene promoter-controlled, and fluorescent reporter-labeled CRISPR interference system in .

The dCas9-based Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) interference (CRISPRi) gene regulation technique requires two components: a catalytically inactive Cas9 protein (dCas9) and a single-guide RNA that targets the gene of interest. This system is commonly activated by expressing dCas9 through an inducible gene promoter, but these inducers may affect cellular physiology, and accessibility and permeability of the inducer are limited in relevant model systems. Here, we have developed an alternative approach for CRISPRi activation in the clinical isolate USA300 LAC, where dCas9 was expressed through endogenous virulence gene promoters (vgp); coagulase, autolysin, or fibronectin-binding protein A.

Bacterial genomic epidemiology with mixed samples.

Genomic epidemiology is a tool for tracing transmission of pathogens based on whole-genome sequencing. We introduce the mGEMS pipeline for genomic epidemiology with plate sweeps representing mixed samples of a target pathogen, opening the possibility to sequence all colonies on selective plates with a single DNA extraction and sequencing step. The pipeline includes the novel mGEMS read binner for probabilistic assignments of sequencing reads, and the scalable pseudoaligner Themisto.

Prevalence and prognostic implication of iron deficiency and anaemia in patients with severe aortic stenosis.

Objective: The aim of this study was to evaluate the prevalence and prognostic implication of iron deficiency (ID) and anaemia in patients with severe aortic stenosis (AS).

Methods: In an observational study of consecutive patients referred for aortic valve replacement (AVR), we assessed a wide range of biomarkers of iron status, including the definition of ID commonly applied in patients with chronic heart failure (ferritin <100 µg/L or ferritin 100-299 µg/L with a transferrin saturation <20%). The endpoints were short-term (one-year) and long-term (median 4.