Nrf2, a PPARγ Alternative Pathway to Promote CD36 Expression on Inflammatory Macrophages: Implication for Malaria

CD36 is the major receptor mediating nonopsonic phagocytosis of Plasmodium falciparum-parasitized erythrocytes by macrophages. Its expression on macrophages is mainly controlled by the nuclear receptor PPARγ. Here, we demonstrate that inflammatory processes negatively regulate CD36 expression on human and murine macrophages, and hence decrease Plasmodium clearance directly favoring the worsening of malaria infection. This CD36 downregulation in inflammatory conditions is associated with a failure in the expression and activation of PPARγ. Interestingly, using siRNA mediating knock down of Nrf2 in macrophages or Nrf2- and PPARγ-deficient macrophages, we establish that in inflammatory conditions, the Nrf2 transcription factor controls CD36 expression independently of PPARγ. In these conditions, Nrf2 activators, but not PPARγ ligands, enhance CD36 expression and CD36-mediated Plasmodium phagocytosis. These results were confirmed in human macrophages and in vivo where only Nrf2 activators improve the outcome of severe malaria. Collectively, this report highlights that the Nrf2 transcription factor could be an alternative target to PPARγ in the control of severe malaria through parasite clearance

Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Abstract: In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M ⊙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded

Epidemiology and mechanisms of resistance of Aspergillus fumigatus to triazole antifungal drugs : focus on patients with cystic fibrosis

Aspergillus fumigatus est un champignonfilamenteux opportuniste.Aspergillus fumigatus is an opportunistic filamentous fungus, causing various clinical manifestations. The first-line treatment of aspergillosis is triazole antifungal drugs. The emergence of the resistance of A. fumigatus to this class of antifungals is a worrying and monitored phenomenon. The most frequent resistance mechanism involves 14 - demethylase, the target enzyme of azoles (encoded by the cyp51A gene). Two origins of resistance have been proposed: the first related to the selection of resistant isolates during long-term antifungal treatment and the second, an environmental origin following the use of demethylation inhibitor fungicides in the environment. Our work highlighted, for the first time, the presence of TR46/Y121F/T289A isolates in France. Furthermore, the exploration of the genotypic link between clinical and environmental isolates carrying the TR46/Y121F/T289A alteration validated the hypothesis of the environmental origin of azole resistance. A prospective one-year study in cystic fibrosis patients confirmed a relatively high level prevalence of resistance together with the presence of wild-type cyp51A resistant isolates. The latter isolates were investigated for yet unidentified resistance mechanisms, initially analysing the sterol biosynthesis pathway. This work contributes to a better knowledge of the epidemiology and resistance mechanisms of A. fumigatus to azole drugs

Evaluation du spectromètre de masse Matrix Assisted Laser Desorption Ionization-Time Of Flight (MALDI-TOF) Vitek® MS dans le laboratoire de mycologie médicale du centre hospitalier universitaire de Toulouse

BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

Comment on Mugisha et al. J Med Primatol 2010; 39: 71-76.

Comment on : A novel herpesvirus in the sanctuary chimpanzees on Ngamba Island in Uganda. [J Med Primatol. 2010]International audienceLetter to the Edito

Hormographiella aspergillata: an emerging basidiomycete in the clinical setting? A case report and literature review

International audienceBackground: Filamentous basidiomycetes are mainly considered to be respiratory tract colonizers but the clinical significance of their isolation in a specimen is debatable. Hormographiella aspergillata was first reported as a human pathogen in 1971. We discuss the role of this mold as a pathogen or colonizer and give an update on diagnostic tools and in vitro antifungal susceptibility. Case presentation: We identified three cases of H. aspergillata with respiratory symptoms in a short period of time. One invasive infection and two colonizations were diagnosed. Culture supernatants showed that H. aspergillata can produce galactomannan and β-D-glucan but not glucuronoxylomannan. For the first time, isavuconazole susceptibility was determined and high minimum inhibitory concentrations (MICs) were found. Liposomal amphotericin B and voriconazole have the lowest MICs. Conclusion: To date, 22 invasive infections involving H. aspergillata have been reported. On isolation of H. aspergillata, its pathogenic potential in clinical settings can be tricky. Molecular identification and antifungal susceptibility testing are essential considering high resistance against several antifungal therapies

Serological diagnosis of Toxoplasma gondii: analysis of false-positive IgG results and implications

International audienceBackground: Primary infection by Toxoplasma gondii in pregnant women can result in serious outcomes for the foetus. A false-positive IgG result during pregnancy can lead to a misdiagnosis of past infection and to stopping preventive measures. We collected 189 sera with positive Architect® Toxo IgG assay (Abbott Laboratories) and negative IgG results with at least two other serological tests, in order to find an explanation for the suspected false-positive IgG results. We used the recomLine Toxoplasma IgG® immunoblot (Mikrogen Diagnostik) to search for specific antigenic reactivities of the sera, and the LDBio Toxo II IgG® immunoblot (LDBio Diagnostics) as a confirmatory test. Results: The bands GRA8 and/or GRA7 were positive for 148 samples (78.3%). GRA8 was the most frequent band, appearing in 133 patterns (70.4%), whereas GRA7 was present for 49 samples (25.9%). Of the 81 samples tested with LDBio®, 23 (28.4%) turned out to be positive. Of the 58 negative LDBio® tests (71.6%) (real false-positive Architect® IgG), 23 samples (39.6%) did not show either a GRA8 or p30 band by recomLine®. Their false positivity with Architect® remains unexplained since Abbott uses these two recombinant antigens for their assay. Conclusions: The Architect® IgG false positivity for T. gondii seems to be due to reactivity against GRA8 for the majority of the sera and GRA7 to a lesser extent. The hypothesis of past contact with parasites genetically close to T. gondii such as Hammondia hammondi or Neospora caninum seems promising and should be assessed further

Serum (1 → 3)‐β‐D‐glucan could be useful to rule out invasive candidiasis in neonates with an adapted cut‐off

International audienceAim We assessed the diagnostic accuracy of serum (1 -> 3)-beta-D-glucan (BDG) for neonatal invasive candidiasis (NIC) using the recommended cut-off usually used in adults for detecting invasive candidiasis and searched for an optimal cut-off for ruling out NIC.Methods We conducted a prospective cross-sectional study at Nantes University medical centre from January 2017 to July 2018. All consecutive newborn infants of less than 28 days of corrected age, with clinically suspected NIC, who underwent BDG assay, were included. Sensitivity and specificity were calculated by using the recommended cut-off of 80 pg/mL. Receiver operating characteristic curve analysis was used to identify an optimal cut-off value.Results We included 55 newborn infants with 61 episodes of suspected NIC. Their median gestational and chronological ages were 28.0 weeks (interquartile range [IQR] 26.4-34.1) and 10.0 days (IQR 6.0-22.0), respectively. Of 61 episodes, seven revealed NIC. Sensitivity and specificity were 85.7% (95% confidence interval [CI] 42.1%-99.6%) and 51.9% (37.8%-65.7%) with the recommended cut-off, respectively. An optimal cut-off of 174 pg/mL offered the same sensitivity but higher specificity 77.8% (64.4%-88.0%).Conclusion The recommended cut-off of 80 pg/mL was probably too low for ruling out NIC. A higher cut-off might have been more appropriate