Institute Pasteur Of La Guyane

Cayenne, French Guiana

Institute Pasteur Of La Guyane

Cayenne, French Guiana
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Matheus S.,Institute Pasteur Of La Guyane | Pham T.B.,Far East Medical Vietnam Ltd | Labeau B.,Institute Pasteur Of La Guyane | Huong V.T.Q.,Institute Pasteur Vietnam | And 3 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2014

Large-scale epidemiological surveillance of dengue in the field and dengue patient management require simple methods for sample collection, storage, and transportation as well as effective diagnostic tools. We evaluated the kinetics of three biological markers of dengue infection - non-structural protein 1 (NS1) antigen, immunoglobulin M (IgM), and IgA - in sequential capillary blood samples collected from fingertips of confirmed dengue patients. The overall sensitivities and specificities of the tests were 96% and 100%, respectively, for NS1, 58.1% and 100%, respectively, for IgM, and 33% and 100%, respectively, for IgA. During the acute phase of the disease, NS1 was the best marker of dengue infection, with a sensitivity of 98.7%, whereas from day 5, all three markers exhibited relevant levels of sensitivity. This first descriptive study of the kinetics of biological markers of dengue in capillary blood samples confirms the usefulness of this biological compartment for dengue diagnosis and argues for its exploitation in community-level and remote settings. Copyright © 2014 by The American Society of Tropical Medicine and Hygiene.

Dormoi J.,Institute Of Recherche Biomedicale Des Armees | Dormoi J.,Aix - Marseille University | Briolant S.,Institute Of Recherche Biomedicale Des Armees | Briolant S.,Aix - Marseille University | And 4 more authors.
Malaria Journal | Year: 2013

Background: Proveblue®, a methylene blue dye that complies with European Pharmacopoeia and contains limited organic impurities and heavy metals of recognized toxicity, showed in vitro synergy against Plasmodium falciparum when combined with atorvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl- Coenzyme A reductase. The objective of this study was to evaluate the in vivo efficacy of Proveblue® when combined with atorvastatin in a murine model of experimental cerebral malaria. Methods. Forty female C57Bl6/N mice were divided into four groups (control, atorvastatin 40 mg/kg for seven days, Proveblue® 10 mg/kg for five days and atorvastatin combined with Proveblue®), infected with Plasmodium berghei ANKA parasites by intraperitoneal inoculation and observed for 45 days. Results: Treatment with atorvastatin alone did not demonstrate an effect significantly different from no treatment (p = 0.0573). All the mice treated by atorvastatin alone died. Treatment with Proveblue® or a combination of Proveblue® and atorvastatin was significantly increased survival of cerebral malaria (p = 0.0011 and 0.0002, respectively). Although there was only one death in the atorvastatin and Proveblue® combination treatment group (10%) versus two deaths (22%) with Proveblue® treatment, the effect on cerebral malaria was not significant (p = 0.283). Conclusions: The present work demonstrated, for the first time, the high efficacy of Proveblue® in preventing cerebral malaria. Atorvastatin alone or in combination appears to possess limited use for preventing cerebral malaria. Combination of atorvastatin with lower doses of Proveblue® (<10 mg/kg/day) should be evaluated to show potential synergistic effects in cerebral malaria prevention. © 2013 Dormoi et al.; licensee BioMed Central Ltd.

Dormoi J.,Institute Of Recherche Biomedicale Des Armees | Dormoi J.,Aix - Marseille University | Briolant S.,Institute Of Recherche Biomedicale Des Armees | Briolant S.,Aix - Marseille University | And 4 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2013

Although 100% of untreated mice infected with Plasmodium berghei died with specific signs of cerebral malaria and 100% of mice treated with 3 mg/kg dihydroartemisinin, the active metabolite of artesunate, which is used as the first-line treatment for severe malaria, also died but showed no specific signs of cerebral malaria, 78% of mice treated with 10 mg/kg Proveblue (methylene blue) and 78% of mice treated with a combination of 3 mg dihydroartemisinin and 10 mg/kg Proveblue survived and showed no specific signs of cerebral malaria or detectable parasites. Copyright © 2013, American Society for Microbiology.

Cockburn J.J.B.,Institute Pasteur Paris | Cockburn J.J.B.,French National Center for Scientific Research | Navarro Sanchez M.E.,Institute Pasteur Paris | Navarro Sanchez M.E.,French National Center for Scientific Research | And 12 more authors.
EMBO Journal | Year: 2012

The four serotypes of dengue virus (DENV-1 to-4) cause the most important emerging viral disease. Protein E, the principal viral envelope glycoprotein, mediates fusion of the viral and endosomal membranes during virus entry and is the target of neutralizing antibodies. However, the epitopes of strongly neutralizing human antibodies have not been described despite their importance to vaccine development. The chimpanzee Mab 5H2 potently neutralizes DENV-4 by binding to domain I of E. The crystal structure of Fab 5H2 bound to E from DENV-4 shows that antibody binding prevents formation of the fusogenic hairpin conformation of E, which together with in-vitro assays, demonstrates that 5H2 neutralizes by blocking membrane fusion in the endosome. Furthermore, we show that human sera from patients recovering from DENV-4 infection contain antibodies that bind to the 5H2 epitope region on domain I. This study, thus, provides new information and tools for effective vaccine design to prevent dengue disease. © 2012 European Molecular Biology Organization | All Rights Reserved.

Dusfour I.,Institute Pasteur Of La Guyane | Carinci R.,Institute Pasteur Of La Guyane | Issaly J.,Institute Pasteur Of La Guyane | Gaborit P.,Institute Pasteur Of La Guyane | Girod R.,Institute Pasteur Of La Guyane
Journal of Vector Ecology | Year: 2013

In French Guiana, Anopheles darlingi is considered the main malaria vector. However, several reports have hypothesized the implication of other anopheline species in malaria transmission for the territory. Data on the ecology of these other potential vectors is rare or even unexplored in French Guiana. The aim of this study was to describe the biting habits of several anopheline species in multiple localities in French Guiana. Six sampling sites yielded 1,083 anopheline adults. Results indicated the presence of An. darlingi in all study locations and it was the only species to be collected inside villages. Other anophelines collected included An. aquasalis, An. braziliensis, An. intermedius, An. mediopunctatus, An. nuneztovari, An. oswaldoi, and An. triannulatus, all of which were associated with open areas and forests. The environment and time, at which biting behavior was recorded, varied for each species. It was noted that An. oswaldoi showed a daytime rhythm in open areas. This study is the first to report on the biting habits of a range of anophelines in French Guiana that may play a role in malaria transmission. This information is vital to fully describe the risk of malaria transmission and thereby design appropriate vector control measures and malaria prevention programs. © 2013 The Society for Vector Ecology.

Dusfour I.,Institute Pasteur Of La Guyane | Thalmensy V.,Institute Pasteur Of La Guyane | Gaborit P.,Institute Pasteur Of La Guyane | Issaly J.,Institute Pasteur Of La Guyane | And 2 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2011

In French Guiana, pyrethroids and organophosphates have been used for many years against Aedes aegypti. We aimed to establish both the resistance level of Ae. aegypti and the ultra low volume spray efficacy to provide mosquito control services with practical information to implement vector control and resistance management. Resistance to deltamethrin and fenitrothion was observed. In addition, the profound loss of efficacy of AquaK'othrine® and the moderate loss of efficacy of Paluthion® 500 were recorded. Fenitrothion remained the most effective candidate for spatial application in French Guiana until its removal in December 2010. Further investigation of the mechanism of resistance to deltamethrin demonstrated the involvement of mixed-function oxidases and, to a lesser extent, of carboxylesterases. However, these observations alone cannot explain the level of insecticide resistance we observed during tube and cage tests.

Valderramos S.G.,Columbia University | Valderramos S.G.,Yeshiva University | Valderramos J.-C.,Yeshiva University | Musset L.,Yeshiva University | And 5 more authors.
PLoS Pathogens | Year: 2010

Mutant forms of the Plasmodium falciparum transporter PfCRT constitute the key determinant of parasite resistance to chloroquine (CQ), the former first-line antimalarial, and are ubiquitous to infections that fail CQ treatment. However, treatment can often be successful in individuals harboring mutant pfcrt alleles, raising questions about the role of host immunity or pharmacokinetics vs. the parasite genetic background in contributing to treatment outcomes. To examine whether the parasite genetic background dictates the degree of mutant pfcrt-mediated CQ resistance, we replaced the wild type pfcrt allele in three CQ-sensitive strains with mutant pfcrt of the 7G8 allelic type prevalent in South America, the Oceanic region and India. Recombinant clones exhibited strain-dependent CQ responses that ranged from high-level resistance to an incremental shift that did not meet CQ resistance criteria. Nonetheless, even in the most susceptible clones, 7G8 mutant pfcrt enabled parasites to tolerate CQ pressure and recrudesce in vitro after treatment with high concentrations of CQ. 7G8 mutant pfcrt was found to significantly impact parasite responses to other antimalarials used in artemisininbased combination therapies, in a strain-dependent manner. We also report clinical isolates from French Guiana that harbor mutant pfcrt, identical or related to the 7G8 haplotype, and manifest a CQ tolerance phenotype. One isolate, H209, harbored a novel PfCRT C350R mutation and demonstrated reduced quinine and artemisinin susceptibility. Our data: 1) suggest that high-level CQR is a complex biological process dependent on the presence of mutant pfcrt; 2) implicate a role for variant pfcrt alleles in modulating parasite susceptibility to other clinically important antimalarials; and 3) uncover the existence of a phenotype of CQ tolerance in some strains harboring mutant pfcrt. © 2010 Valderramos et al.

Lacoste V.,Institute Pasteur Of La Guyane | Lavergne A.,Institute Pasteur Of La Guyane | de Thoisy B.,Institute Pasteur Of La Guyane | Pouliquen J.-F.,Institute Pasteur Of La Guyane | Gessain A.,Institute Pasteur Paris
Infection, Genetics and Evolution | Year: 2010

The Gammaherpesvirinae sub-family is divided into two genera: Lymphocryptovirus and Rhadinovirus. Until the middle of the 1990s, the Rhadinovirus genus was only represented by Herpesvirus saimiri and Herpesvirus ateles, which infect New World monkey species. Until the year 2000, Epstein-Barr virus (EBV), the human prototype of the Lymphocryptovirus, and simian homologues had only been detected in humans and Old World non-human primates. It was thought, therefore, that the separation of the continents had resulted in drastic changes in Gammaherpesvirinae evolution. The discovery of Kaposi's sarcoma-associated herpesvirus in humans, belonging to the Rhadinovirus, followed by the identification of CalHV3 (Callitrichine herpesvirus 3), a lymphocryptovirus of the marmoset, challenged this paradigm. The description of numerous viruses belonging to this sub-family from various Old and New World primate species enabled a cospeciation hypothesis for these viruses and their hosts to be developed. This review focuses on the current knowledge of primate Gammaherpesvirinae genetic diversity and molecular evolution. We discuss the various theories based on current genetic data regarding evolutionary relationships between lymphocryptoviruses of Old World primates, the use of these data as a tool to study evolutionary relationships between New World monkey species, and the possible existence of a ninth human herpesvirus belonging to the Rhadinovirus genus. © 2009 Elsevier B.V. All rights reserved.

Simonnet C.,Institute Pasteur Of La Guyane | Berger F.,Institute Pasteur Of La Guyane | Gantier J.-C.,Institute Pasteur Paris
Medical Mycology | Year: 2011

A three-year retrospective analysis of fungi isolated from specimens of patients with superficial fungal infections in French Guiana is presented. Clinical samples from 726 patients with presumptive diagnoses of onychomycosis (28.2% of the patients), tinea capitis (27.8%), superficial cutaneous mycoses of the feet (22.0%), and of other areas of the body (21.9%), were assessed by microscopic examination and culture. Dermatophytes accounted for 59.2% of the isolates, followed by yeasts (27.5%) and non-dermatophytic molds (13.1%). Trichophyton rubrum was the most common dermatophyte recovered from cases of onychomycosis (67.4%), tinea pedis (70.6%) and tinea corporis (52.4%). In contrast, Trichophyton tonsurans was the predominant species associated with tinea capitis (73.9%). Yeasts were identified as the principal etiologic agents of onychomycosis of the fingernails (74.2%), whereas molds were found mainly in cases of onychomycosis of the toenails. In such instances, Neoscytalidium dimidiatum (70.8%) was the most common mold recovered in culture. In conclusion, the prevalence of T. rubrum and the occurrence of onychomycosis and fungal infections of the feet in French Guiana are similar to results reported from Europe, whereas the frequency of tinea capitis and the importance of T. tonsurans in such infections are similar to the situation in the Americas. © 2011 ISHAM.

Dusfour I.,Institute Pasteur Of La Guyane | Issaly J.,Institute Pasteur Of La Guyane | Carinci R.,Institute Pasteur Of La Guyane | Gaborit P.,Institute Pasteur Of La Guyane | Girod R.,Institute Pasteur Of La Guyane
Memorias do Instituto Oswaldo Cruz | Year: 2012

Anopheles darlingi Root is the major vector of human malaria in the Neotropics and has been considered to be the sole malaria vector in French Guiana. The presence of other potential vectors suggests that malaria may be transmitted by other species under certain conditions. From 2006-2011, all anopheline specimens collected from 11 localities were assayed to determine if the Plasmodium circumsporozoite protein was present. In addition to An. darlingi, we found Anopheles oswaldoi, Anopheles intermedius and Anopheles nuneztovari specimens that were infected with Plasmodium sp. Further investigations on the behaviour and ecology of An. oswaldoi, An. intermedius and An. nuneztovari are necessary to determine their role in malaria transmission in French Guiana.

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