Human Nasal Challenge with Streptococcus pneumoniae Is Immunising in the Absence of Carriage

Infectious challenge of the human nasal mucosa elicits immune responses that determine the fate of the host-bacterial interaction; leading either to clearance, colonisation and/or disease. Persistent antigenic exposure from pneumococcal colonisation can induce both humoral and cellular defences that are protective against carriage and disease. We challenged healthy adults intra-nasally with live 23F or 6B Streptococcus pneumoniae in two sequential cohorts and collected nasal wash, bronchoalveolar lavage (BAL) and blood before and 6 weeks after challenge. We hypothesised that both cohorts would successfully become colonised but this did not occur except for one volunteer. The effect of bacterial challenge without colonisation in healthy adults has not been previously assessed. We measured the antigen-specific humoral and cellular immune responses in challenged but not colonised volunteers by ELISA and Flow Cytometry. Antigen-specific responses were seen in each compartment both before and after bacterial challenge for both cohorts. Antigen-specific IgG and IgA levels were significantly elevated in nasal wash 6 weeks after challenge compared to baseline. Immunoglobulin responses to pneumococci were directed towards various protein targets but not capsular polysaccharide. 23F but not 6B challenge elevated IgG anti-PspA in BAL. Serum immunoglobulins did not increase in response to challenge. In neither challenge cohort was there any alteration in the frequencies of TNF, IL-17 or IFNγ producing CD4 T cells before or after challenge in BAL or blood. We show that simple, low dose mucosal exposure with pneumococci may immunise mucosal surfaces by augmenting anti-protein immunoglobulin responses; but not capsular or cellular responses. We hypothesise that mucosal exposure alone may not replicate the systemic immunising effect of experimental or natural carriage in humans

SOS Response Induces Persistence to Fluoroquinolones in Escherichia coli

Bacteria can survive antibiotic treatment without acquiring heritable antibiotic resistance. We investigated persistence to the fluoroquinolone ciprofloxacin in Escherichia coli. Our data show that a majority of persisters to ciprofloxacin were formed upon exposure to the antibiotic, in a manner dependent on the SOS gene network. These findings reveal an active and inducible mechanism of persister formation mediated by the SOS response, challenging the prevailing view that persisters are pre-existing and formed purely by stochastic means. SOS-induced persistence is a novel mechanism by which cells can counteract DNA damage and promote survival to fluoroquinolones. This unique survival mechanism may be an important factor influencing the outcome of antibiotic therapy in vivo

Implementation of preventive strength training in residential geriatric care: a multi-centre study protocol with one year of interventions on multiple levels

<p>Abstract</p> <p>Background</p> <p>There is scientific evidence that preventive physical exercise is effective even in high age. In contrast, there are few opportunities of preventive exercise for highly aged people endangered by or actually in need of care. For example, they would not be able to easily go to training facilities; standard exercises may be too intensive and therefore be harmful to them; orientation disorders like dementia would exacerbate individuals and groups in following instructions and keeping exercises going. In order to develop appropriate interventions, these and other issues were assigned to different levels: the individual-social level (ISL), the organisational-institutional level (OIL) and the political-cultural level (PCL). Consequently, this conceptional framework was utilised for development, implementation and evaluation of a new strength and balance exercise programme for old people endangered by or actually in need of daily care. The present paper contains the development of this programme labeled "fit for 100", and a study protocol of an interventional single-arm multi-centre trial.</p> <p>Methods</p> <p>The intervention consisted of (a) two group training sessions every week over one year, mainly resistance exercises, accompanied by sensorimotor and communicative group exercises and games (ISL), (b) a sustainable implementation concept, starting new groups by instructors belonging to the project, followed by training and supervision of local staff, who stepwise take over the group (OIL), (c) informing and convincing activities in professional, administrative and governmental contexts, public relation activities, and establishing an advisory council with renowned experts and public figures (PCL). Participating institutions of geriatric care were selected through several steps of quality criteria assessment. Primary outcome measures were continuous documentation of individual participation (ISL), number of groups continued without external financial support (at the end of the project, and after one year) (OIL). Secondary outcome was measured by sensorimotor tests and care-related assessments in the beginning and every 16 weeks (ISL), by qualitative outcome descriptions 12 months after group implementation (OIL) and by analysis of media response and structured interviews with stakeholders, also after 12 months (PCL).</p> <p>Conclusion</p> <p>Exemplarily, preventive exercise has been established for a neglected target population. The multi-level approach used here seems to be helpful to overcome institutional and individual (attitude) barriers.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN55213782</p

Stromal IFN-γR-Signaling Modulates Goblet Cell Function During Salmonella Typhimurium Infection

Enteropathogenic bacteria are a frequent cause of diarrhea worldwide. The mucosal defenses against infection are not completely understood. We have used the streptomycin mouse model for Salmonella Typhimurium diarrhea to analyze the role of interferon gamma receptor (IFN-γR)-signaling in mucosal defense. IFN-γ is known to contribute to acute S. Typhimurium diarrhea. We have compared the acute mucosal inflammation in IFN-γR-/- mice and wild type animals. IFN-γR-/- mice harbored increased pathogen loads in the mucosal epithelium and the lamina propria. Surprisingly, the epithelium of the IFN-γR-/- mice did not show the dramatic “loss” of mucus-filled goblet cell vacuoles, a hallmark of the wild type mucosal infection. Using bone marrow chimeric mice we established that IFN-γR-signaling in stromal cells (e.g. goblet cells, enterocytes) controlled mucus excretion/vacuole loss by goblet cells. In contrast, IFN-γR-signaling in bone marrow-derived cells (e.g. macrophages, DCs, PMNs) was required for restricting pathogen growth in the gut tissue. Thus IFN-γR-signaling influences different mucosal responses to infection, including not only pathogen restriction in the lamina propria, but, as shown here, also goblet cell function

Change & Maintaining Change in School Cafeterias: Economic and Behavioral-Economic Approaches to Increasing Fruit and Vegetable Consumption

Developing a daily habit of consuming fruits and vegetables (FV) in children is an important public-health goal. Eating habits acquired in childhood are predictive of adolescent and adult dietary patterns. Thus, healthy eating patterns developed early in life can protect the individual against a number of costly health deficits and may reduce the prevalence of obesity. At present, children in the United States (US) under-consume FV despite having access to them through the National School Lunch Program. Because access is an obstacle to developing healthy eating habits, particularly in low-income households, targeting children’s FV consumption in schools has the advantage of near-universal FV availability among more than 30 million US children. This chapter reviews economic and behavioral-economic approaches to increasing FV consumption in schools. Inclusion criteria include objective measurement of FV consumption (e.g., plate waste measures) and minimal demand characteristics. Simple but effective interventions include (a) increasing the variety of vegetables served, (b) serving sliced instead of whole fruits, (c) scheduling lunch after recess, and (d) giving children at least 25 minutes to eat. Improving the taste of FV and short-term incentivizing consumption of gradually increasing amounts can produce large increases in consumption of these foods. Low-cost game-based incentive program may increase the practicality of the latter strategy

Genes Required for Growth at High Hydrostatic Pressure in Escherichia coli K-12 Identified by Genome-Wide Screening

Despite the fact that much of the global microbial biosphere is believed to exist in high pressure environments, the effects of hydrostatic pressure on microbial physiology remain poorly understood. We use a genome-wide screening approach, combined with a novel high-throughput high-pressure cell culture method, to investigate the effects of hydrostatic pressure on microbial physiology in vivo. The Keio collection of single-gene deletion mutants in Escherichia coli K-12 was screened for growth at a range of pressures from 0.1 MPa to 60 MPa. This led to the identification of 6 genes, rodZ, holC, priA, dnaT, dedD and tatC, whose products were required for growth at 30 MPa and a further 3 genes, tolB, rffT and iscS, whose products were required for growth at 40 MPa. Our results support the view that the effects of pressure on cell physiology are pleiotropic, with DNA replication, cell division, the cytoskeleton and cell envelope physiology all being potential failure points for cell physiology during growth at elevated pressure