14 research outputs found
Molecular Markers of In Vivo Plasmodium vivax Resistance to Amodiaquine Plus Sulfadoxine-Pyrimethamine: Mutations in pvdhfr and pvmdr1
Background. Molecular markers for sulfadoxine-pyrimethamine (SP) resistance in Plasmodium vivax have been reported. However, data on the molecular correlates involved in the development of resistance to 4-aminoquinolines and their association with the in vivo treatment response are scarce. Methods. We assessed pvdhfr (F57L/I, S58R, T61M, S117T/N, and I173F/L) and pvmdr1 (Y976F and F1076L) mutations in 94 patients who received amodiaquine (AQ) plus SP in Papua New Guinea (PNG). We then investigated the association between parasite genotype and treatment response. Results. The treatment failure (TF) rate reached 13%. Polymorphisms in pvdhfr F57L, S58R, T61M, and S117T/N and in pvmdr1 Y976F were detected in 60%, 67%, 20%, 40%, and 39% of the samples, respectively. The single mutant pvdhfr 57 showed the strongest association with TF (odds ratio [OR], 9.04; P=.01). The combined presence of the quadruple mutant pvdhfr 57L+58R+61M+117T and pvmdr1 mutation 976F was the best predictor of TF (OR, 8.56; P=.01). The difference in TF rates between sites was reflected in the genetic drug-resistance profile of the respective parasites. Conclusions. The present study identified a new molecular marker in pvmdr1 that is associated with the in vivo response to AQ+SP. We suggest suitable marker sets with which to monitor P. vivax resistance against AQ+SP in countries where these drugs are use
A systematic review and meta-analysis of evidence for correlation between molecular markers of parasite resistance and treatment outcome in falciparum malaria
<p>Abstract</p> <p>Background</p> <p>An assessment of the correlation between anti-malarial treatment outcome and molecular markers would improve the early detection and monitoring of drug resistance by <it>Plasmodium falciparum</it>. The purpose of this systematic review was to determine the risk of treatment failure associated with specific polymorphisms in the parasite genome or gene copy number.</p> <p>Methods</p> <p>Clinical studies of non-severe malaria reporting on target genetic markers (SNPs for <it>pfmdr1</it>, <it>pfcrt</it>, <it>dhfr</it>, <it>dhps</it>, gene copy number for <it>pfmdr1</it>) providing complete information on inclusion criteria, outcome, follow up and genotyping, were included. Three investigators independently extracted data from articles. Results were stratified by gene, codon, drug and duration of follow-up. For each study and aggregate data the random effect odds ratio (OR) with 95%CIs was estimated and presented as Forest plots. An OR with a lower 95<sup>th </sup>confidence interval > 1 was considered consistent with a failure being associated to a given gene mutation.</p> <p>Results</p> <p>92 studies were eligible among the selection from computerized search, with information on <it>pfcrt </it>(25/159 studies), <it>pfmdr1 </it>(29/236 studies), <it>dhfr </it>(18/373 studies), <it>dhps </it>(20/195 studies). The risk of therapeutic failure after chloroquine was increased by the presence of <it>pfcrt </it>K76T (Day 28, OR = 7.2 [95%CI: 4.5â11.5]), <it>pfmdr1 </it>N86Y was associated with both chloroquine (Day 28, OR = 1.8 [95%CI: 1.3â2.4]) and amodiaquine failures (OR = 5.4 [95%CI: 2.6â11.3, p < 0.001]). For sulphadoxine-pyrimethamine the <it>dhfr </it>single (S108N) (Day 28, OR = 3.5 [95%CI: 1.9â6.3]) and triple mutants (S108N, N51I, C59R) (Day 28, OR = 3.1 [95%CI: 2.0â4.9]) and <it>dhfr</it>-<it>dhps </it>quintuple mutants (Day 28, OR = 5.2 [95%CI: 3.2â8.8]) also increased the risk of treatment failure. Increased <it>pfmdr1 </it>copy number was correlated with treatment failure following mefloquine (OR = 8.6 [95%CI: 3.3â22.9]).</p> <p>Conclusion</p> <p>When applying the selection procedure for comparative analysis, few studies fulfilled all inclusion criteria compared to the large number of papers identified, but heterogeneity was limited. Genetic molecular markers were related to an increased risk of therapeutic failure. Guidelines are discussed and a checklist for further studies is proposed.</p
Détection des polymorphismes nucléotidiques pour la surveillance des résistances de Plasmodium falciparum
LYON1-BU Santé (693882101) / SudocSudocFranceF
Déterminisme génomique et post-génomique de la résistance de Plasmodium falciparum aux antipaludéens
L'impact médical du paludisme est la conséquence de la résistance de P.falciparum à la plupart des antipaludéens. L'étude de la résistance repose sur les tests in vivo et les tests in vitro. Leurs contraintes respectives limitent leur capacité à produire des résultats rapides. L'objectif de ce travail est de développer une méthode permettant de distinguer les espÚces plasmodiales, de mesurer la sensibilité du parasite et de détecter les mutations. La PCR en temps réel nous a permis de déterminer la sensibilité à la chloroquine de souches de culture, la charge parasitaire de patients traités par antipaludéens et d'identifier les 4 espÚces plasmodiales. L'utilisation de sondes d'hybridation a permis d'établir le polymorphisme de 217 échantillons collectés sur anticoagulant ou sur papier buvard pour 3 loci du gÚne pfcrt et 5 loci du gÚne pfmdr1. L'utilisation de cette méthode doit permettre d'établir une base comportant les données essentielles à la définition rapide d'une politique thérapeutique de premiÚre et deuxiÚme intention.LYON1-BU Santé (693882101) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF
Characterisation of polyglutamylases in trypanosomatids
International audienceMicrotubules are subject to post-translational modifications, which are thought to have crucial roles in the function of complex microtubule-based organelles. Among these, polyglutamylation was relatively recently discovered, and was related to centrosome stability, axonemal maintenance and mobility, and neurite outgrowth. In trypanosomatids, parasitic protozoa where microtubules constitute the essential component of the cytoskeleton, the function of polyglutamylated microtubules is unknown. Here, in order to better understand the role of this conserved but highly divergent post-translational modification, we characterised glutamylation and putative polyglutamylases in these parasites. We showed that microtubules are intensely glutamylated in all stages of the cell cycle, including interphase. Moreover, a cell cycle-dependent gradient of glutamylation was observed along the cell anteroposterior axis, which might be related to active growth of the microtubule 'corset' during the cell cycle. We also identified two putative polyglutamylase proteins (among seven analysed here) which appeared to be clearly and directly involved in microtubule polyglutamylation in in vitro activity assays. Paradoxically, in view of the importance of tubulins and of their extensive glutamylation in these organisms, RNA interference-based knockdown of all these proteins had no effect on cell growth, suggesting either functional redundancy or, more likely, subtle roles such as function modulation or interaction with protein partners
Advantages and limits of real-time PCR assay and PCR-restriction fragment length polymorphism for the identification of cutaneous Leishmania species in Tunisia.
International audienceCutaneous leishmaniasis (CL), a public health problem in Tunisia, is associated to three species: Leishmania (L.) infantum, L. major and L. killicki. Accurate and sensitive procedures for the diagnostic of Leishmania infection and for species identification are required to enable adequate treatment and appropriate control measures. Several PCR-methods are applied for the diagnosis and the identification of Leishmania parasites such as PCR-restriction fragment length polymorphism (PCR-RFLP), DNA sequencing, hybridization probes and real-time PCR (RT-PCR). In this study, PCR-RFLP and RT-PCR were performed on skin scrapings from 27 patients with confirmed CL by microscopic examination, in order to compare their usefulness and efficiency for identification of Leishmania species in routine diagnostic laboratories. Identification of Leishmania species was successfully achieved in 96.3% and 81.5% respectively. Agreement between using internal transcribed spacer 1 (ITS1)-PCR-RFLP and kDNA-RT-PCR assays was 70% (19/27). Characterization problems using RT-PCR were mainly due to the difficulties in analyzing the melting temperatures. ITS1-PCR-RFLP and kDNA-RT-PCR presented an interesting alternative to conventional methods for the identification of Leishmania parasites from clinical samples. Both PCR assays can be used in a routine diagnostic, however, further prospective studies including largest sampling, are required to determine their performances in a routine use
Marine protected areas in fisheries management: Synthesis on the state of the art
83 pagesâThe international context shows that many MPAs overall objectives, identified in international Conventions, werenot achieved in 2012 and consequently were repeated: âBy 2020, at least ⊠10 per cent of coastal and marine areas,especially areas of particular importance for biodiversity and ecosystem services, are conserved through effectivelyand equitably managed, ecologically representative and well-connected systems of protected areas and other effectivearea-based conservation measures, and integrated into the wider landscapes and seascapesâ (CBD Strategic Plan2011-2020, Goal C, Target 11, CBD CoP10, Decision X2, Nagoya 2010).The present document aims to present the results of ananalysis of the world literature, draw lessons from learnedexperiences, and share relevant recommendationswith regard to situations experienced in the SRFC zone onthe best ways and means to use MPAs as fisheries managementtools.Through the future programs of the SRFC and States ofthe region, the challenges will be the best utilization ofthe recommendations contained therein in order to, onthe one hand, improve the relations between the governancesof coastal management, fisheries, and MPAs and,on the other hand, to develop solutions enabling a betterintegration of the concerns of fisheries in the managementof MPAs and of the MPAs in the management of fisheries..The work, conducted by a group of experts from the Universityof Brest (UMR Amure) â Agrocampus from Rennes(fisheries) â the IUCN-CEM Fisheries Expert Group coordinatedby BRL Engineering and EBCD and supported bymany international contributions, has highlighted a seriesof illustrative examples and case-studies on MPAs inthree main documents:â A âtechnical reportâ in french representing the State ofthe Art made up with 4 volumes dealing with âGovernanceâ,âsocio-economic and bio-economic modellingâ,âbio-ecological and bioecological modellingâ, and âElementof Reflection for the SRFC and its partnersâ in supportto the regional Workshop;â The present âSynthesis Reportâ ;â A ten-page note summarizing the outcomes of thestudy (www.spcsrp.org).These works as well as the supporting document andthoughts they produced enabled the holding of a regionalworkshop in December 2011 in Dakar during which theoutcomes of the review were presented. Exchanges withseveral representatives of fisheries and environmentalinstitutions and other stakeholders throughout the subregion(fishermen, funders, scientists, etc.,) led to confirmationof the relevance of the supporting documents ofthe Workshop and specified further the recommendationspresented in this document.âThree main questions are asked in this study:â Are MPAs tools preferable to conventional fishery managementtools when it comes to promoting :(1) theparticular protection of certain areas, habitats or, species;(ii) the, allocation of resources; and (iii) the participationof communities in the decision-making process?â What lessons have been learned on the effects of MPAson fishing and on the tools associated to the measurementof these effects?â Are there any lessons to be drawn from the internationalexperience on governance of MPAs in relation to fishingthat could lead to improvements in management
Les aires marines protĂ©gĂ©es dans la gestion des pĂȘches.: SynthĂšse de l' Ă©tat de l'art.
83 pagesLe contexte international indique que de nombreux objectifs globaux des AMP nâont pas pu ĂȘtre atteint en 2012comme prĂ©vu dans les conventions internationales et sont donc reconduits : « En 2020, au moins⊠10% des zones cĂŽtiĂšreset marines revĂȘtant une importance particuliĂšre⊠seront conservĂ©es par des systĂšmes dâAMP, gĂ©rĂ©s eficacement,Ă©cologiquement reprĂ©sentatifs et correctement connectĂ©s, ainsi que par dâautres mesures de conservationspatiales efficaces, et intĂ©grĂ©s dans des paysages⊠marins plus vastes (CdP 10, 2010, Nagoya, DĂ©cision X/2, Plan StratĂ©gique2011-2020).Le prĂ©sent document vise Ă disposer dâune analyse de lalittĂ©rature mondiale afin de tirer les enseignements etpartager des recommandations pertinentes aux situationsrencontrĂ©es dans la rĂ©gion CSRP sur les meilleursvoies et moyens dâutiliser des AMP gĂ©rĂ©es en tant quâoutilsdâamĂ©nagement des pĂȘches.Les enjeux Ă travers les programmes futurs de la CSRP etdes Etats de la rĂ©gion seront de valoriser ces travaux afindâamĂ©liorer les relations entre les gouvernances de la gestioncĂŽtiĂšre, des pĂȘches, et des AMP mais aussi de dĂ©velopperdes solutions permettant de mieux intĂ©grer lesprĂ©occupations de la pĂȘche dans la gestion des AMP etdes AMP dans la gestion des pĂȘches.Le travail fourni par un groupe dâexpert, composĂ© de lâuniversitĂ©de Brest (UMR Amure)-Agrocampus (halieutique)-UICN-EBCD, coordonnĂ© par BRL ingĂ©nierie et appuyĂ© parde nombreuses contributions internationales, a mis en valeurune sĂ©rie dâexemples illustratifs et de cas dâĂ©tudes ausein de 3 documents principaux :â Un ârapport techniqueâ reprĂ©sentant le corps de lâĂ©tatde lâart constituĂ© en 4 volumes autour dâun volet âGouvernanceâ,dâun volet âsocioĂ©conomie et modĂ©lisationbioĂ©conomiqueâ, dâun volet âbioĂ©cologie et modĂ©lisationbiologiqueâ et dâun volet âElĂ©ment de rĂ©flexion pour laCSRP et ses partenaires» en appui Ă lâAtelier rĂ©gionalâ ;â Le prĂ©sent ârapport de synthĂšseâ ;â Une note de 10 pages qui rĂ©sume les conclusions delâĂ©tude (www.spcsrp.org).Ces travaux ainsi que le document dâappui et de rĂ©flexionsur les recommandations ont permis la rĂ©alisation dâunAtelier rĂ©gional en dĂ©cembre 2011 Ă Dakar durant lequelont Ă©tĂ© prĂ©sentĂ©s les rĂ©sultats. Les Ă©changes avec de nombreuxreprĂ©sentants dâinstitutions des pĂȘches et de lâenvironnementet dâacteurs de toute la sous-rĂ©gion(pĂȘcheurs, financeurs, scientifiques,âŠ) ont permis de validerla pertinence des documents dâappui Ă lâAtelier et deprĂ©ciserles recommandations qui sont prĂ©sentĂ©es dans ce document.âTrois grandes questions sont abordĂ©es dans cet ouvrage :â Est-ce que les AMP sont des instruments prĂ©fĂ©rablesaux instruments conventionnels de gestion despĂȘches lorsquâil sâagit de promouvoir la protectionparticuliĂšre de certaines zones, habitats, espĂšces,lâallocation des ressources, la participation descommunautĂ©s Ă la dĂ©cision ?â Quels sont les enseignements sur les effets, les outilsassociĂ©s Ă la mesure des effets des AMP sur la pĂȘche ?â Existe-t-il des enseignements Ă tirer de lâexpĂ©rienceinternationale en matiĂšre de gouvernance des AMPen lien avec la pĂȘche et permettant des amĂ©liorationsdans la gestion
Good Efficacy of Artemether-Lumefantrine for Uncomplicated Falciparum Malaria in Eastern Sumba, East Nusatenggara, Indonesia
Aim: to evaluate the safety and efficacy of a fixed combination of artemether-lumefantrine for likely use against failures of the artesunate-amodiaquine first line therapy. Methods: the study was an open label single arm uncontrolled trial. we evaluated the safety and efficacy of standard artemether-lumefantrine therapy in 59 subjects with uncomplicated malaria caused by Plasmodium falciparum on the island of Sumba in eastern Indonesia. No treatment failures occurred up to day 35. One subject had recurrent parasitemia on day 42 that showed a genotype consistent with recrudescence. The efficacy of this therapy was thus estimated to be 98.3% (95% confidence interval=95%-100%). Descriptive analysis was done using the SPSS 12 computer software. Results: two hundred and thirteen P. falciparum patients met the inclusion criteria for in vivo efficacy study, 79 were given artemether-lumefantrine and 134 were treated under another protocol with artesunate-amodiaquine or sulfadoxine-pyrimethamine. Among 79 eligible subjects, 59 successfully completed the 42-day test. As expected, the mean PCT was longer than the mean FCT, i.e. 1.34+-0.67 (95% CI 1.21â1.47) and 1.05+-0.05 (95% CI 0.95â1.15) days, respectively. On day 3 of treatment, both fever and asexual stage of P. falciparum disappeared in all subjects. Observation until Day 35 showed that all of the 59 subjects treated with artemether-lumefantrine were cured. Conclusion: the findings of this uncontrolled study suggest good safety and efficacy of artemether-lumefantrine for treatment of uncomplicated falciparum malaria on Sumba Island in the Lesser Sundas archipelago of eastern Indonesia