Laboratoire Of Bacteriologie Virologie

Dakar, Senegal

Laboratoire Of Bacteriologie Virologie

Dakar, Senegal
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Mourez T.,Institute Pasteur Paris | Mourez T.,Laboratoire Of Bacteriologie Virologie | Mourez T.,University Paris Diderot | Mesel-Lemoine M.,Institute Pasteur Paris | And 4 more authors.
Virology | Year: 2011

We generated a replicating chimeric measles virus in which the hemagglutinin and fusion surface glycoproteins were replaced with the gp160 envelope glycoprotein of simian immunodeficiency virus (SIVmac239). Based on a previously cloned live-attenuated Schwarz vaccine strain of measles virus (MV), this chimera was rescued at high titers using reverse genetics in CD4+ target cells. Cytopathic effect consisted in the presence of large cell aggregates evolving to form syncytia, as observed during SIV infection. The morphology of the chimeric virus was identical to that of the parent MV particles. The presence of SIV gp160 as the only envelope protein on chimeric particles surface altered the cell tropism of the new virus from CD46+ to CD4+ cells. Used as an HIV candidate vaccine, this MV/SIVenv chimeric virus would mimic transient HIV-like infection, benefiting both from HIV-like tropism and the capacity of MV to replicate in dendritic cells, macrophages and lymphocytes. © 2011 Elsevier Inc.

De Beaudrap P.,Montpellier University | Thiam M.,Laboratoire Of Bacteriologie Virologie | Diouf A.,Multisectorial AIDS Program | Toure-Kane C.,Laboratoire Of Bacteriologie Virologie | And 7 more authors.
Journal of Acquired Immune Deficiency Syndromes | Year: 2013

Background: In 1998, Senegal launched one of Africa's first antiretroviral therapy (ART) programs. Since then, the number of treated patients in Africa has substantially increased thanks to simplification in treatment management. Although good outcomes over the first years of ART have been observed in sub-Saharan Africa, little is known about the long-term (.5 years) risks of virological failure and drug resistance and about second-line treatment response. Methods: Patients from the ANRS-1215 cohort in Senegal, started with either one nonnucleoside reverse transcriptase inhibitor or indinavir, a first-generation nonboosted protease inhibitor, followed for .6 months and having .1 viral load (VL) measurement were included. Virological failure was defined as 2 consecutive VL measurements .1000 copies/mL. Results: Of the 366 patients included, 89% achieved a VL ,500 copies/mL. The risk of virological failure at 12, 24, and 60 months was 5%, 16%, and 25%, being higher in younger patients (P = 0.05), those receiving a protease inhibitor-containing regimen (P = 0.05), and those with lower adherence (P = 0.03). The risk of resistance to any drug at 12, 24, and 60 months was 3%, 11%, and 18%. After virological failure, 60% of the patients were switched to second-line treatments. Although 81% of the patients achieved virological success, the risk of virological failure was 27% at 24 months, mostly in patients with multiple resistances. Conclusions: In this cohort, virological outcomes for first-line treatments were good compared with those from high-resource settings. However, the rate of virological failure for second-line treatment was high, probably because of accumulation of resistances. Copyright © 2012 by Lippincott Williams & Wilkins.

Monleau M.,Montpellier University | Monleau M.,French National Center for Scientific Research | Aghokeng A.F.,Montpellier University | Aghokeng A.F.,Virology Laboratory | And 10 more authors.
Journal of Clinical Microbiology | Year: 2014

Dried blood spots (DBS) can be used in developing countries to alleviate the logistic constraints of using blood plasma specimens for viral load (VL) and HIV drug resistance (HIVDR) testing, but they should be assessed under field conditions. Between 2009 and 2011, we collected paired plasma-DBS samples from treatment-experienced HIV-1-infected adults in Burkina Faso, Cameroon, Senegal, Togo, Thailand, and Vietnam. The DBS were stored at an ambient temperature for 2 to 4 weeks and subsequently at-20°C before testing. VL testing was performed on the plasma samples and DBS using locally available methods: the Abbott m2000rt HIV-1 test, generic G2 real-time PCR, or the NucliSENS EasyQ version 1.2 test. In the case of virological failure (VF), i.e., a plasma VL of>1,000 copies/ml, HIVDR genotyping was performed on paired plasma-DBS samples. Overall, we compared 382 plasma-DBS sample pairs for DBS VL testing accuracy. The sensitivities of the different assays in different laboratories for detecting VF using DBS varied from 75% to 100% for the m2000rt test in labs B, C, and D, 91% to 93% for generic G2 realtime PCR in labs A and F, and 85% for the NucliSENS test in lab E. The specificities varied from 82% to 97% for the m2000rt and NucliSENS tests and reached only 60% for the generic G2 test. The NucliSENS test showed good agreement between plasma and DBS VL but underestimated the DBS VL. The lowest agreement was observed for the generic G2 test. Genotyping was successful for 96/124 (77%) DBS tested, and 75/96 (78%) plasma-DBS pairs had identical HIVDR mutations. Significant discrepancies in resistance interpretations were observed in 9 cases, 6 of which were from the same laboratory. DBS can be successfully used as an alternative to blood plasma samples for routine VL and HIVDR monitoring in African and Asian settings. However, the selection of an adequate VL measurement method and the definition of the VF threshold should be considered, and laboratory performance should be monitored. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Abgueguen P.,Service des Maladies Infectieuses et tropicales | Delbos V.,Unite de prevention et de lutte contre les infections nosocomiales | Ducancelle A.,Laboratoire Of Bacteriologie Virologie | Jomaa S.,Service des Maladies Infectieuses et tropicales | And 2 more authors.
Clinical Microbiology and Infection | Year: 2010

In the present study, we retrospectively studied clinical and laboratory findings associated with cytomegalovirus (CMV) infection in immunocompetent patients. We focused on severe CMV infection. Among 38 patients, five had a severe form of infection: one had meningitis, one had symptomatic thrombocytopenia and three had venous thromboses with pulmonary embolism, a rarely described complication. CMV-induced thrombosis has been reported in immunocompromised patients such as transplant recipients and patients with AIDS. Recent case reports have also described thrombotic phenomena in immunocompetent patients with CMV infection. Our study suggests that venous thrombosis during acute CMV infection is an underestimated complication. © 2009 The Authors. Journal Compilation © 2009 European Society of Clinical Microbiology and Infectious Diseases.

Fouquet M.,Service durologie | Morange V.,Laboratoire Of Bacteriologie Virologie | Bruyere F.,Service durologie
Progres en Urologie | Year: 2012

Introduction: Actually, epidemiology of extended-spectrum β-lactamase (ESBL) producing enterobacteriaceae is increasing worldwide, especially in urinary tract infections (UTI). The objective of the study was to investigate the epidemiology of ESBL producers in a department of urology. Patients and methods: This was a retrospective, monocentric study, which included all patients with positive culture showing an ESBL producing enterobacteriaceae in a department of urology between 2005 and 2009 included. Results: The prevalence of ESBL producers in UTI was 2/113 (1.8%) in 2005 and 3/196 (1.5%) in 2009 (P= 0.87). Twenty-seven isolates were included: 66.7% of Escherichia coli, 11.1% of Klebsiella pneumoniae, 11.1% of Enterobacter cloacae. ESBL producers were resistant to another antibiotic family in 24 cases (88.8%). The mean age in this study was 70.4 years, 70% of patients had another antibiotherapy in the past 6 months, 87% an hospitalization within 90% had surgery. Among the patients, 56.5% had a material. The infection was community-acquired in three cases only. Thirty-five percent of patients had no symptoms, 26% presented with severe sepsis. Conclusion: This report was a five-year retrospective study of BLSE-positive bacteria showing the nosocomial infection with ESBL producers and their multiresistance to usual antibiotics without any increase of their prevalence. © 2011 Elsevier Masson SAS.

The purpose of this study was to evaluate the bacterial profile and antimicrobial susceptibility of surgical site infection (SSI) as a basis for optimizing probabilistic antibiotherapy. A 6-month transversal retrospective study was carried out at the Souro Sano Hospital Laboratory from November 1st, 2006 to April 30th, 2007. All positive pus samples collected for etiologic diagnosis of SSI were included. In a series of 681 patients who underwent surgery at the hospital, SSI was observed in 159 cases for an incidence of 23.4%. Pus samples for etiologic diagnosis were collected from 112 patients and led to identification of 103 bacterial strains. The most common strains were enterobacteriaceae in 54.0%, gram-positive cocci in 29.0% and non-fermenting Gram-negative bacilli in 16.5%. Escherichia coli was the most common species (30%) followed by Staphylococcus aureus (16.5%) and Pseudomonas aeroginosa (12.0%). Enterobacteriaceae resistance rates were 71% to amoxicillin, 64% to clavulanic acid-amoxicillin and 15% to third generation cephalosporin. Most S. aureus isolates (85%) were sensitive to methicillin. Non-fermenting Gram-negative bacilli resistance rates were 68.5% to carboxypenicillin and 56% to fluoroquinolones. These findings indicate that SSI can be treated using third generation cephalosporin-aminosides in combination with oral fluoroquinolones.

Braibant M.,French Institute of Health and Medical Research | Gong E.-Y.,French Institute of Health and Medical Research | Gong E.-Y.,Beatson Institute for Cancer Research | Plantier J.-C.,University of Rouen | And 5 more authors.
AIDS | Year: 2013

Objective: HIV-1 has been classified into four groups: M, N, O and P. The aim of this study was to revisit the cross-group neutralization using a highly diverse panel of primary isolates. Design: The panel of viruses included nine HIV-1 group O primary isolates, one recombinant M/O primary isolate, one group N primary isolates, one group P primary isolate, two group M (subtype B) primary isolates and the HIV-1 group M adapted strain MN. Methods: All the viruses were tested for neutralization in TZM-bl cells, using sera issued from patients infected by viruses of group M (n = 11), O (n = 12) and P (n = 1), and a panel of nine human monoclonal broadly neutralizing antibodies (HuMo bNAbs). Results: Although the primary isolates displayed a wide spectrum of sensitivity to neutralization by the human sera, cross-group neutralization was clearly observed. In contrast, the bNAbs did not show any cross-group neutralization, except PG9 and PG16. Interestingly, the group N prototype strain YBF30 was highly sensitive to neutralization by PG9 (IC50: 0.28 (μg/ml) and PG16 (IC50: < 0.12 (μg/ml). The interaction between PG9 and key residues of YBF30 was confirmed by molecular modeling. Conclusion: The conservation of the PG9 and PG16 epitopes within groups M and N provides an argument for their relevance as components of a potentially efficient HIV vaccine immunogen. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Maylin S.,Laboratoire Of Virologie | Maylin S.,French Institute of Health and Medical Research | Maylin S.,University Paris Diderot | Boyd A.,French Institute of Health and Medical Research | And 14 more authors.
AIDS | Year: 2012

Objective: Hepatitis B surface (HBs-Ag) and envelope (HBeAg) antigen loss are the primary goals of treating chronic hepatitis B virus (HBV). Although their quantification is useful for other antivirals, such has not been the case with tenofovir disoproxil fumarate (TDF), particularly in HIV infection. DESIGN:: Prospective, multicenter, cohort study in 143 antiretroviral- experienced HIV-HBV-co-infected patients initiating TDF. Methods: HBsAg (IU/ml) and HBeAg levels (S/CO) were measured every 6 months. HBsAg and HBeAg decline (Δ) were assessed by mixed-effect linear models. Quantification criteria were used to assess predictability of antigen loss with time-dependent receiver operating characteristic curves. Results: After a median follow-up of 30.3 months, cumulative incidence rate of HBsAg loss was 4.0% (n=4) in the entire study population and HBeAg loss was 21.0% (n=17) in the 96 HBeAg-positive patients. ΔHBsAg was steady during follow-up (HBeAg-positive: -0.027; HBeAg-negative: -0.017log10IU/ml per month), whereas ΔHBeAg ratio was strongly biphasic (-27.1S/CO per month before and -6.5S/CO per month after 18 months). Baseline HBeAg and ΔHBeAg were significantly different in patients harboring precore mutations (P<0.01), whereas both ΔHBsAg and ΔHBeAg were significantly slower among HBeAg-positive patients with CD4 + T-cell count less than 350 cells/μl (P< 0.05). HBeAg-ratio of 10S/CO or less at 12 months of therapy was the optimal marker of HBeAg loss, with high sensitivity (0.82) and specificity (0.84) at 36 months. In patients with HBsAg loss, three of four (75.0%) patients had a baseline level of HBsAg of 400 IU/ml or less. Conclusion: During TDF treatment, HIV-induced immunosuppression and HBV genetic variability are associated with differences in HBsAg and HBeAg decline among antiretroviral-experienced, co-infected patients. Considering the decline of HBsAg level is slow, further evaluation is needed to determine its role as a marker of therapeutic efficacy. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Berthet J.,Jean Monnet University | Damien P.,Jean Monnet University | Hamzeh-Cognasse H.,Jean Monnet University | Arthaud C.-A.,EFS Auvergne Loire | And 7 more authors.
Clinical Immunology | Year: 2012

Platelets are currently acknowledged as cells of innate immunity and inflammation and play a complex role in sepsis. We examined whether different types of LPS have different effects on the release of soluble signaling/effective molecules from platelets. We used platelet-rich plasma from healthy volunteers and LPS from two strains of gram-negative bacteria with disparate LPS structures. We combined LPS-stimulated platelet supernatants with reporter cells and measured the PBMC cytokine secretion profiles. Upon stimulation of platelets with both Escherichia coli O111 and Salmonella minnesota LPS, the platelet LPS::TLR4 interaction activated pathways to trigger the production of a large number of molecules. The different platelet supernatants caused differential PBMC secretion of IL-6, TNFα, and IL-8. Our data demonstrate that platelets have the capacity to sense external signals differentially through a single type of pathogen recognition receptor and adjust the innate immune response appropriately for pathogens exhibiting different types of 'danger' signals. © 2012 Elsevier Inc.

PubMed | Institute Pasteur in Cambodia, Montpellier University, Laboratoire Of Virologie, CHU Sanou Souro and 3 more.
Type: Journal Article | Journal: Journal of clinical microbiology | Year: 2016

The impact of HIV-1 DNA coamplification during HIV-1 RNA quantification on dried blood spots (DBS) was explored. False-positive HIV RNA detection (22/62, 35%) was associated with high HIV-1 DNA levels. Specificity of HIV-1 RNA assays on DBS should be evaluated following manufacturer protocols on samples with HIV-1 DNA levels of 1,000 copies/10(6) peripheral blood mononuclear cells.

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