Environmental and genetic regulation of Streptococcus pneumoniae galactose catabolic pathways.

Efficient utilization of nutrients is crucial for microbial survival and virulence. The same nutrient may be utilized by multiple catabolic pathways, indicating that the physical and chemical environments for induction as well as their functional roles may differ. Here, we study the tagatose and Leloir pathways for galactose catabolism of the human pathogen Streptococcus pneumoniae. We show that galactose utilization potentiates pneumococcal virulence, the induction of galactose catabolic pathways is influenced differentially by the concentration of galactose and temperature, and sialic acid downregulates galactose catabolism. Furthermore, the genetic regulation and in vivo induction of each pathway differ, and both galactose catabolic pathways can be turned off with a galactose analogue in a substrate-specific manner, indicating that galactose catabolic pathways can be potential drug targets.

Handheld Computer Devices to Support Clinical Decision-making in Acute Nursing Practice: Systematic Scoping Review.

BACKGROUND: Nursing care is increasingly supported by computerized information systems and decision support aids. Since the advent of handheld computer devices (HCDs), there has been limited exploration of their use in nursing practice. OBJECTIVE: The study aimed to understand the professional and clinical impacts of the use of mobile health apps in nursing to assist clinical decision-making in acute care settings. The study also aimed to explore the scope of published research and identify key nomenclature with respect to research in this emerging field within nursing practice. METHODS: This scoping review involved a tripartite search of electronic databases (CINAHL, Embase, MEDLINE, and Google Scholar) using preliminary, broad, and comprehensive search terms. The included studies were hand searched for additional citations. Two researchers independently screened the studies for inclusion and appraised quality using structured critical appraisal tools. RESULTS: Of the 2309 unique studies screened, 28 (1.21%) were included in the final analyses: randomized controlled trials (n=3, 11%) and quasi-experimental (n=9, 32%), observational (n=10, 36%), mixed methods (n=2, 7%), qualitative descriptive (n=2, 7%), and diagnostic accuracy (n=2, 7%) studies. Studies investigated the impact of HCDs on nursing decisions (n=12, 43%); the effectiveness, safety, and quality of care (n=9, 32%); and HCD usability, uptake, and acceptance (n=14, 50%) and were judged to contain moderate-to-high risk of bias. The terminology used to describe HCDs was heterogenous across studies, comprising 24 unique descriptors and 17 individual concepts that reflected 3 discrete technology platforms ("PDA technology," "Smartphone/tablet technology," and "Health care-specific technology"). Study findings varied, as did the range of decision-making modalities targeted by HCD interventions. Interventions varied according to the level of clinician versus algorithmic judgment: unstructured clinical judgment, structured clinical judgment, and computerized algorithmic judgment. CONCLUSIONS: The extant literature is varied but suggests that HCDs can be used effectively to support aspects of acute nursing care. However, there is a dearth of high-level evidence regarding this phenomenon and studies exploring the degree to which HCD implementation may affect acute nursing care delivery workflow. Additional targeted research using rigorous experimental designs is needed in this emerging field to determine the true potential of HCDs in optimizing acute nursing care.

Pneumococcal capsule expression is controlled through a conserved, distal cis-regulatory element during infection.

Streptococcus pneumoniae (the pneumococcus) is the major cause of bacterial pneumonia in the US and worldwide. Studies have shown that the differing chemical make-up between serotypes of its most important virulence factor, the capsule, can dictate disease severity. Here we demonstrate that control of capsule synthesis is also critical for infection and facilitated by two broadly conserved transcription factors, SpxR and CpsR, through a distal cis-regulatory element we name the 37-CE. Strikingly, changing only three nucleotides within this sequence is sufficient to render pneumococcus avirulent. Using in vivo and in vitro approaches, we present a model where SpxR interacts as a unique trimeric quaternary structure with the 37-CE to enable capsule repression in the airways. Considering its dramatic effect on infection, variation of the 37-CE between serotypes suggests this molecular switch could be a critical contributing factor to this pathogen's serotype-specific disease outcomes.

Siglec-5 is an inhibitory immune checkpoint molecule for human T cells.

Sialic acid-binding immunoglobulin-type lectins (Siglecs) are a family of immunoglobulin-type lectins that mediate protein-carbohydrate interactions via sialic acids attached to glycoproteins or glycolipids. Most of the CD33-related Siglecs (CD33rSiglecs), a major subfamily of rapidly evolving Siglecs, contain a cytoplasmic signaling domain consisting of the immunoreceptor tyrosine-based inhibitory motif (ITIM) and immunoreceptor tyrosine-based switch motif (ITSM) and mediate suppressive signals for lymphoid and myeloid cells. While most CD33rSiglecs are expressed by innate immune cells, such as monocytes and neutrophils, to date, the expression of Siglecs in human T cells has not been well appreciated. In this study, we found that Siglec-5, a member of the CD33rSiglecs, is expressed by most activated T cells upon antigen receptor stimulation. Functionally, Siglec-5 suppresses T cell activation. In support of these findings, we found that Siglec-5 overexpression abrogates antigen receptor induced activation of NFAT and AP-1. Furthermore, we show that GBS ß-protein, a known bacterial ligand of Siglec-5, reduces the production of cytokines and cytolytic molecules by activated primary T cells in a Siglec-5 dependent manner. Our data also show that some cancer cell lines express a putative Siglec-5 ligand(s), and that the presence of soluble Siglec-5 enhances tumor-cell specific T cell activation, suggesting that some tumor cells inhibit T cell activation via Siglec-5. Together, our data demonstrate that Siglec-5 is a previously unrecognized inhibitory T cell immune checkpoint molecule and suggest that blockade of Siglec-5 could serve as a new strategy to enhance anti-tumor T cell functions.

Evaluation of the effectiveness of an eLearning program in the nursing observation and assessment of acute surgical patients: A naturalistic observational study.

AIM/OBJECTIVE: The aim of this study was to evaluate the effectiveness of an eLearn program in changing surgical nurses' approach to clinical assessment. BACKGROUND: Nurses need to have the knowledge and skills to recognise and respond to changes in patients' physiological condition in a timely manner. A private health service in Melbourne, Australia developed an online (eLearn) program highlighting the importance of clinical assessment and provided nurses with an overview of the Airway,Breathing, Circulation, Disability, Exposures ('ABCDE') approach. DESIGN: A before and after study design that involved naturalistic observation of nurse-patient interactions and nurses' performing patient clinical assessments was undertaken on two surgical wards. METHODS: The intervention ward nurses received standard education and exposure to the eLearning program. The comparison ward nurses received standard workplace education on patient assessment. The nurses were observed from May to August 2018. RESULTS: Following completion of the eLearn, intervention ward nurses were observed to spend more time with their patients conducting clinical assessment. On both wards, not all nurses performed comprehensive ABCDE assessment and there was variability associated with the sequencing of ABCDE assessment. CONCLUSIONS: This study provides some evidence that completion of an eLearn can change clinical practice, however the intensity of the intervention was insufficient to achieve optimal practice in the conduct of clinical assessments.

A High-Throughput Method for Identifying Novel Genes That Influence Metabolic Pathways Reveals New Iron and Heme Regulation in Pseudomonas aeruginosa.

Heme is an essential metabolite for most life on earth. Bacterial pathogens almost universally require iron to infect a host, often acquiring this nutrient in the form of heme. The Gram-negative pathogen Pseudomonas aeruginosa is no exception, where heme acquisition and metabolism are known to be crucial for both chronic and acute infections. To unveil unknown genes and pathways that could play a role with heme metabolic flux in this pathogen, we devised an omic-based approach we dubbed "Met-Seq," for metabolite-coupled transposon sequencing. Met-Seq couples a biosensor with fluorescence-activated cell sorting (FACS) and massively parallel sequencing, allowing for direct identification of genes associated with metabolic changes. In this work, we first construct and validate a heme biosensor for use with P. aeruginosa and exploit Met-Seq to identify 188 genes that potentially influence intracellular heme levels. Identified genes largely consisted of metabolic pathways not previously associated with heme, including many secreted virulence effectors, as well as 11 predicted small RNAs (sRNAs) and riboswitches whose functions are not currently understood. We verify that five Met-Seq hits affect intracellular heme levels; a predicted extracytoplasmic function (ECF) factor, a phospholipid acquisition system, heme biosynthesis regulator Dnr, and two predicted antibiotic monooxygenase (ABM) domains of unknown function (PA0709 and PA3390). Finally, we demonstrate that PA0709 and PA3390 are novel heme-binding proteins. Our data suggest that Met-Seq could be extrapolated to other biological systems and metabolites for which there is an available biosensor, and provides a new template for further exploration of iron/heme regulation and metabolism in P. aeruginosa and other pathogens.IMPORTANCE The ability to simultaneously and more directly correlate genes with metabolite levels on a global level would provide novel information for many biological platforms yet has thus far been challenging. Here, we describe a method to help address this problem, which we dub "Met-Seq" (metabolite-coupled Tn sequencing). Met-Seq uses the powerful combination of fluorescent biosensors, fluorescence-activated cell sorting (FACS), and next-generation sequencing (NGS) to rapidly identify genes that influence the levels of specific intracellular metabolites. For proof of concept, we create and test a heme biosensor and then exploit Met-Seq to identify novel genes involved in the regulation of heme in the pathogen Pseudomonas aeruginosa Met-Seq-generated data were largely comprised of genes which have not previously been reported to influence heme levels in this pathogen, two of which we verify as novel heme-binding proteins. As heme is a required metabolite for host infection in P. aeruginosa and most other pathogens, our studies provide a new list of targets for potential antimicrobial therapies and shed additional light on the balance between infection, heme uptake, and heme biosynthesis.

RitR is an archetype for a novel family of redox sensors in the streptococci that has evolved from two-component response regulators and is required for pneumococcal colonization.

To survive diverse host environments, the human pathogen Streptococcus pneumoniae must prevent its self-produced, extremely high levels of peroxide from reacting with intracellular iron. However, the regulatory mechanism(s) by which the pneumococcus accomplishes this balance remains largely enigmatic, as this pathogen and other related streptococci lack all known redox-sensing transcription factors. Here we describe a two-component-derived response regulator, RitR, as the archetype for a novel family of redox sensors in a subset of streptococcal species. We show that RitR works to both repress iron transport and enable nasopharyngeal colonization through a mechanism that exploits a single cysteine (Cys128) redox switch located within its linker domain. Biochemical experiments and phylogenetics reveal that RitR has diverged from the canonical two-component virulence regulator CovR to instead dimerize and bind DNA only upon Cys128 oxidation in air-rich environments. Atomic structures show that Cys128 oxidation initiates a "helical unravelling" of the RitR linker region, suggesting a mechanism by which the DNA-binding domain is then released to interact with its cognate regulatory DNA. Expanded computational studies indicate this mechanism could be shared by many microbial species outside the streptococcus genus.

Developing professional attributes in critical care nurses using Team-Based Learning.

Australian nurses prepare for specialty practice by undertaking postgraduate theoretical and clinical education in partnership models between universities and hospitals. In our global healthcare system, nurses require advanced critical thinking and strong communication skills to provide safe, high quality patient care. Yet, few education programs focus on developing these skills. Team-Based Learning (TBL) is a specific educational strategy that encourages and rewards students to think critically and solve clinical problems individually and in teams. The aim of this study was to investigate critical care nursing students' perceptions and experiences of TBL after it was introduced into the second half of their postgraduate specialty course. Following Ethics Committee approval, thirty-two students were invited to participate in an extended response questionnaire on their perceptions of TBL as part of a larger study. Data were analyzed thematically. Postgraduate students perceived their professional growth was accelerated due to the skills and knowledge acquired through TBL. Four themes underpinned the development and accelerated acquisition of specialty nurse attributes due to TBL: Engagement, Learning Effectiveness, Critical Thinking, and Motivation to Participate. Team-Based Learning offered deep and satisfying learning experiences for students. The early acquisition of advanced critical thinking, teamwork and communication skills, and specialty practice knowledge empowered nurses to provide safe patient care with confidence.

Evaluation of postgraduate critical care nursing students' attitudes to, and engagement with, Team-Based Learning: a descriptive study.

OBJECTIVE: The aim of this study was to evaluate postgraduate critical care nursing students' attitudes to, and engagement with, Team-Based Learning (TBL). RESEARCH METHODOLOGY/DESIGN: A descriptive pre and post interventional design was used. Study data were collected by surveys and observation. SETTING: University postgraduate critical care nursing programme. MAIN OUTCOME MEASURES: Students' attitudes to learning within teams (Team Experience Questionnaire) and student engagement (observed and self-reports). RESULTS: Twenty-eight of 32 students agreed to participate (87% response rate). There were significant changes in students' attitudes to learning within teams including increases in overall satisfaction with team experience, team impact on quality of learning, team impact on clinical reasoning ability and professional development. There was no significant increase in satisfaction with peer evaluation. Observation and survey results showed higher student engagement in TBL classes compared with standard lecturing. CONCLUSION: Postgraduate critical care nursing students responded positively to the introduction of TBL and showed increased engagement with learning. In turn, these factors enhanced nurses' professional skills in teamwork, communication, problem solving and higher order critical thinking. Developing professional skills and advancing knowledge should be core to all critical care nursing education programmes to improve the quality and safety of patient care.