fbl-typing of Staphylococcus lugdunensis: a frontline tool for epidemiological studies

International audienc

Association Between Nutritional Status and the Immune response in HIV + Patients under HAART: Protocol for a Systematic Review.

Over 850 million people worldwide and 200 million adults in Sub-Saharan Africa suffer from malnutrition. Countries most affected by HIV are also stricken by elevated rates of food insecurity and malnutrition. HIV infection and insufficient nutritional intake are part of a vicious cycle that contributes to immunodeficiency and negative health outcomes. However, the effect of the overlap between HIV infection and undernutrition on the immune response following antiretroviral initiation remains unclear. A possible explanation could be the lack of consensus concerning the definition and assessment of nutritional status. Our objectives are to investigate the existence of an association between undernutrition and immune response at antiretroviral treatment initiation and the following year in low- and middle-income countries where malnutrition is most prevalent. Our systematic review will identify studies originating from low- and middle-income countries (LMICs) published from 1996 onwards, through searches in MEDLINE (PubMed interface), EMBASE (OVID interface), Cochrane Central (OVID interface) and grey literature. No language restrictions will be applied. We will seek out studies of any design investigating the association between the nutritional status (for example, undernourished versus well nourished) and the immune response, either in terms of CD4 count or immune failure, in seropositive patients initiating antiretroviral therapy or in their first year of treatment. Two reviewers will independently screen articles, extract data and assess scientific quality using standardized forms and published quality assessment tools tailored for each study design. Where feasible, pooled measures of association will be obtained through meta-analyses. Results will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. This protocol has been registered in the PROSPERO database (registration number: CRD42014005961). Undernutrition and weight loss are prevalent amongst highly active antiretroviral therapy (HAART)-treated patients in LMICs and contribute to excess early mortality. A possible intermediate pathway could be poor immune reconstitution secondary to deficient nutritional status. In the face of limited access to second line treatments, raising HIV resistance and cut backs to HIV programs, it is crucial to identify the factors associated with suboptimal response and therapeutic failure in order to better customize the care strategies employed in LMICs

Apport de la MLVA dans l'épidémiologie moléculaire des infections à Staphylococcus lugdunensis

International audienc

In vitro activity of daptomycin against Enterococcus faecalis under various conditions of growth-phases, inoculum and pH

Enterococcus faecalis (E. faecalis) has become a major leading cause of nosocomial endocarditis. Treatment of such infections remains problematic and new therapeutic options are needed. Nine E. faecalis strains were tested: six obtained from patients presenting endocarditis, one with isolated bacteremia, and two reference strains. Antibiotics included daptomycin, alone or in combination, linezolid, tigecycline, rifampicin, gentamicin, teicoplanin, ceftriaxone and amoxicillin. Time-kill studies included colony counts at 1, 4 and 24 h of incubation. Significant bactericidal activity was defined as a decrease of ≥3log10CFU/ml after 24 h of incubation. Antibiotics were tested at a low (10(6) CFU/ml) and high (10(9) CFU/ml) inoculum, against exponential- and stationary-phase bacteria. We also performed time kill studies of chemically growth arrested E. faecalis. Various pH conditions were used during the tests. In exponential growth phase and with a low inoculum, daptomycin alone at 60 µg/ml and the combination amoxicillin-gentamicin both achieved a 4-log10 reduction in one hour on all strains. In exponential growth phase with a high inoculum, daptomycin alone was bactericidal at a concentration of 120 µg/ml. All the combinations tested with this drug were indifferent. In stationary phase with a high inoculum daptomycin remained bactericidal but exhibited a pH dependent activity and slower kill rates. All combinations that did not include daptomycin were not bactericidal in conditions of high inoculum, whatever the growth phase. The results indicate that daptomycin is the only antibiotic that may be able of overcoming the effects of growth phase and high inoculum

Identifying risk factors for blood culture negative infective endocarditis: An international ID-IRI study

Background: Blood culture-negative endocarditis (BCNE) is a diagnostic challenge, therefore our objective was to pinpoint high-risk cohorts for BCNE. Methods: The study included adult patients with definite endocarditis. Data were collected via the Infectious Diseases International Research Initiative (ID-IRI). The study analysing one of the largest case series ever reported was conducted across 41 centers in 13 countries. We analysed the database to determine the predictors of BCNE using univariate and logistic regression analyses. Results: Blood cultures were negative in 101 (11.65 %) of 867 patients. We disclosed that as patients age, the likelihood of a negative blood culture significantly decreases (OR 0.975, 95 % CI 0.963–0.987, p < 0.001). Additionally, factors such as rheumatic heart disease (OR 2.036, 95 % CI 0.970–4.276, p = 0.049), aortic stenosis (OR 3.066, 95 % CI 1.564–6.010, p = 0.001), mitral regurgitation (OR 1.693, 95 % CI 1.012–2.833, p = 0.045), and prosthetic valves (OR 2.539, 95 % CI 1.599–4.031, p < 0.001) are associated with higher likelihoods of negative blood cultures. Our model can predict whether a patient falls into the culture-negative or culture-positive groups with a threshold of 0.104 (AUC±SE = 0.707 ± 0.027). The final model demonstrates a sensitivity of 70.3 % and a specificity of 57.0 %. Conclusion: Caution should be exercised when diagnosing endocarditis in patients with concurrent cardiac disorders, particularly in younger cases

Lupus érythémateux systémique et lymphopénie : aspects cliniques et physiopathologiques

Résumé La lymphopénie est très fréquente au cours du lupus érythémateux systémique (LES), et profonde (< 500/mm3) dans 10 % des cas. Elle touche principalement les lymphocytes T, notamment CD4+. Les mécanismes physiopathologiques sont complexes, faisant intervenir des anticorps lymphocytotoxiques, un excès d’apoptose, une sensibilité accrue à la lyse par le complément, de même qu’une répression de la lymphopoïèse et des phénomènes de séquestration lymphocytaire. La lymphopénie dans le LES est indépendante des autres cytopénies et des immunosuppresseurs reçus. Elle est associée à l’activité de la maladie, au risque de poussée lupique et aux séquelles viscérales. Le risque infectieux est principalement bactérien, et une lymphopénie < 1 G/L est un facteur de risque indépendant de survenue d’infections sévères bactériennes. Le déficit immunitaire cellulaire T est associé à un moindre contrôle de la réplication virale, mais les infections sévères symptomatiques restent rares. Bien qu’exceptionnelle dans le LES, la pneumocystose y est plus sévère que chez les patients infectés par le VIH, et le risque de leuco-encéphalopathie multifocale progressive semble augmenté comparativement aux autres rhumatismes inflammatoires. À ce jour, il n’existe pas de recommandations spécifiques de prise en charge des LES avec lymphopénie. La prophylaxie anti-infectieuse doit rester exceptionnelle et à discuter au cas par cas. Des études complémentaires sont nécessaires afin d’évaluer précisément les caractéristiques cliniques et évolutives des patients lupiques avec lymphopénie chronique profonde (< 500/mm3), qui constituent très probablement un sous-groupe de LES avec déficit immunitaire primitif associé et nécessitant une prise en charge spécifique. Abstract Lymphopenia is frequent in systemic lupus erythematosus (SLE) and profound (< 500/mm3) in 10% of cases. T lymphocytes, especially CD4+, are more affected than B cells. The pathophysiological mechanisms are complex, involving lymphocytotoxic antibodies, excess of apoptosis, increased susceptibility of T cells to complement mediated cytolysis, as well as lymphopoiesis impairment and lymphocyte sequestration. Lymphopenia in SLE is independent from other cytopenia and immunosuppressive drug regiments, and associated with disease activity, risk of flare and damage scores. Infectious risk is mostly bacterial, and lymphopenia < 1 G/L is an independent risk factor for severe bacterial infections occurrence. The T cellular deficiency is associated with less control of viral replication, but severe and symptomatic infections are scarce. Although exceptional in SLE, pneumocystis is more severe than in HIV+ patients, and risk of progressive multifocal leukoencephalopathy seems increased compared to other rheumatic diseases. To date, there are no specific recommendations for management of SLE with lymphopenia. Infectious prophylaxis should remain exceptional and discussed on a case by case basis. Further studies are needed to assess the clinical characteristics and outcomes of patients with SLE and profound lymphopenia (< 500/mm3), which are probably a subset of SLE with primary immunodeficiency and require specific management