Genome-Wide fitness analysis of group B Streptococcus in human amniotic fluid reveals a transcription factor that controls multiple virulence traits.

Streptococcus agalactiae (group B Streptococcus; GBS) remains a dominant cause of serious neonatal infections. One aspect of GBS that renders it particularly virulent during the perinatal period is its ability to invade the chorioamniotic membranes and persist in amniotic fluid, which is nutritionally deplete and rich in fetal immunologic factors such as antimicrobial peptides. We used next-generation sequencing of transposon-genome junctions (Tn-seq) to identify five GBS genes that promote survival in the presence of human amniotic fluid. We confirmed our Tn-seq findings using a novel CRISPR inhibition (CRISPRi) gene expression knockdown system. This analysis showed that one gene, which encodes a GntR-class transcription factor that we named MrvR, conferred a significant fitness benefit to GBS in amniotic fluid. We generated an isogenic targeted deletion of the mrvR gene, which had a growth defect in amniotic fluid relative to the wild type parent strain. The mrvR deletion strain also showed a significant biofilm defect in vitro. Subsequent in vivo studies showed that while the mutant was able to cause persistent murine vaginal colonization, pregnant mice colonized with the mrvR deletion strain did not develop preterm labor despite consistent GBS invasion of the uterus and the fetoplacental units. In contrast, pregnant mice colonized with wild type GBS consistently deliver prematurely. In a sepsis model the mrvR deletion strain showed significantly decreased lethality. In order to better understand the mechanism by which this newly identified transcription factor controls GBS virulence, we performed RNA-seq on wild type and mrvR deletion GBS strains, which revealed that the transcription factor affects expression of a wide range of genes across the GBS chromosome. Nucleotide biosynthesis and salvage pathways were highly represented among the set of differentially expressed genes, suggesting that MrvR may be involved in regulating nucleotide availability.

Interpreter Use for Limited English Proficiency Patients/Families: A QI Study.

BACKGROUND: Communication is fundamental to high-quality health care. Despite federal requirements to provide interpreters and growing evidence favoring the benefits of interpreter use, providers' use of interpreters remains suboptimal. In acute care settings, where decisions need to be made rapidly on the basis of changing clinical circumstances, this has proven to be challenging. METHODS: We designed a quality improvement project using the model for improvement methodology for patients admitted to the pediatric hospital medicine service. A multidisciplinary team developed interventions focused on provider education and leveraging health information technology (IT). We used health IT to improve the identification of families with limited English proficiency, improve access to various modalities of interpreting, standardize workflow to request face-to-face (F2F) interpreters, and create a designated place in the electronic health record for interpreter use documentation. The use of all forms (telephone, video, and F2F) of interpreter service, documentation of interpreter uses, and F2F interpreter overload were tracked monthly for 3 years. RESULTS: The baseline use of interpreter services for the pediatric hospital medicine inpatient service was 64%. After starting the project, the use of interpreter service increased to 97% and has sustained for more than a year since the project's completion. The use of F2F interpreters also increased from a baseline of 20% to 54% post intervention. CONCLUSIONS: We successfully achieved and sustained our goals of improving interpreter use through supportive leadership and a multidisciplinary approach using quality improvement methodology. Future efforts should be focused on defining and standardizing metrics for families with limited English proficiency across institutions and using health IT to improve care.