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1.
Molecules ; 27(7)2022 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-35408712

RESUMO

There is a need for new, cost-effective drugs to treat leishmaniasis. A strategy based on traditional medicine practiced in Bolivia led to the discovery of the 2-substituted quinoline series as a source of molecules with antileishmanial activity and low toxicity. This review documents the development of the series from the first isolated natural compounds through several hundred synthetized molecules to an optimized compound exhibiting an in vitro IC50 value of 0.2 µM against Leishmania donovani, and a selectivity index value of 187, together with in vivo activity on the L. donovani/hamster model. Attempts to establish structure-activity relationships are described, as well as studies that have attempted to determine the mechanism of action. For the latter, it appears that molecules of this series act on multiple targets, possibly including the immune system, which could explain the observed lack of drug resistance after in vitro drug pressure. We also show how nanotechnology strategies could valorize these drugs through adapted formulations and how a mechanistic targeting approach could generate new compounds with increased activity.


Assuntos
Antiprotozoários , Leishmania donovani , Leishmaniose , Quinolinas , Animais , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Cricetinae , Leishmaniose/tratamento farmacológico , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Relação Estrutura-Atividade
2.
Emerg Infect Dis ; 26(8): 1875-1877, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32687036

RESUMO

We used molecular tools to identify an autochthonous case of gnathostomiasis in Madagascar. This severe ocular infection, caused by Gnathostoma spinigerum nematodes, led to vision loss in the patient's left eye. Clinicians should be aware of this parasitosis in Madagascar and other countries in Africa.


Assuntos
Gnathostoma , Gnatostomíase , África , Animais , Gnatostomíase/diagnóstico , Gnatostomíase/tratamento farmacológico , Gnatostomíase/epidemiologia , Humanos , Madagáscar/epidemiologia
3.
Planta Med ; 86(9): 619-630, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32365395

RESUMO

Pediculosis is a prevalent ectoparasite infestation caused by lice. The head louse (Pediculus humanus capitis) and body louse (Pediculus humanus humanus) are obligatory parasites whose only known hosts are humans. Pediculosis is probably the most common ectoparasitic infestation, affecting up to 80% of the population in several countries, and particularly prevalent in the infant population worldwide. Several treatment options, including shampoos and creams containing insecticides, have been introduced for the treatment of pediculosis. Recently, the use of synthetic chemicals to control human lice has raised concerns pertaining to human health and the environment. Therefore, increasing efforts have been undertaken to develop effective pediculicides with low environmental toxicity and minimal environmental residual activity. In this study, we focus on the essential oils derived from 22 plant genera, their constituents, and the major factors that play important roles in the effectiveness of these oils in the treatment of pediculosis. Furthermore, we discuss the advantages and limitations of the mentioned essential oils, and ultimately suggest those demonstrating the most effective in vitro pediculicidal activities. The genera such as Aloysia, Cinnamomum, Eucalyptus, Eugenia, Lavandula, Melaleuca, Mentha, Myrcianthes, Origanum, Pimpinella, and Thymus appear to be more efficient against lice. These genera are rich in anethole, 1,8-cineole, cinnamaldehyde, p-cymene, eugenol, linalool, limonene, pulegone, terpinen-4-ol, and thymol compounds.


Assuntos
Inseticidas , Infestações por Piolhos , Óleos Voláteis , Pediculus , Animais , Humanos , Óleos de Plantas
4.
Malar J ; 18(1): 422, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31842880

RESUMO

BACKGROUND: With less than one severe case per year in average, Plasmodium vivax is very rarely associated with severe imported malaria in France. Two cases of P. vivax severe malaria occurred in patients with no evident co-morbidity. Interestingly, both cases did not occur at the primary infection but during relapses. CASE PRESENTATIONS: Patient 1: A 27-year old male, born in Afghanistan and living in France since 2012, was admitted on August 2015 to the Avicenne hospital because of abdominal pain, intense headache, fever and hypotension. The patient was haemodynamically unstable despite 5 L of filling solution. A thin blood film showed P. vivax trophozoites within the red blood cells. To take care of the septic shock, the patient was given rapid fluid resuscitation, norepinephrine (0.5 mg/h), and intravenous artesunate. Nested polymerase chain reactions of the SSUrRNA gene were negative for Plasmodium falciparum but positive for P. vivax. The patient became apyretic in less than 24H and the parasitaemia was negative at the same time. Patient 2: A 24-year old male, born in Pakistan and living in France, was admitted on August 2016 because of fever, abdominal pain, headache, myalgia, and nausea. The last travel of the patient in a malaria endemic area occurred in 2013. A thin blood film showed P. vivax trophozoites within the red blood cells. The patient was treated orally by dihydroartemisinin-piperaquine and recovered rapidly. Nine months later, the patient returned to the hospital with a relapse of P. vivax malaria. The malaria episode was uncomplicated and the patient recovered rapidly. Three months later, the patient came back again with a third episode of P. vivax malaria. Following a rapid haemodynamic deterioration, the patient was transferred to the intensive care unit of the hospital. In all the patient received 10 L of filling solution to manage the septic shock. After 5 days of hospitalization and a specific treatment, the patient was discharged in good clinical conditions. CONCLUSION: Clinicians should be aware of the potential severe complications associated with P. vivax in imported malaria, even though the primary infection is uncomplicated.


Assuntos
Doenças Transmissíveis Importadas/diagnóstico , Malária Vivax/diagnóstico , Migrantes , Adulto , Afeganistão , Antimaláricos/uso terapêutico , Doenças Transmissíveis Importadas/parasitologia , França , Humanos , Malária Vivax/tratamento farmacológico , Masculino , Paquistão , Plasmodium vivax/efeitos dos fármacos , Plasmodium vivax/genética , Índice de Gravidade de Doença , Resultado do Tratamento
5.
Parasitol Res ; 117(2): 603-609, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29264717

RESUMO

Treatment of head lice has relied mainly on the use of topical insecticides. Today, conventional topical pediculicides have suffered considerable loss of activity worldwide. There is increasing interest in the use of natural products such as essential oils for head louse control, and many of them are now incorporated into various over-the-counter products presented as pediculicides, often without proper evaluation. The aim of the present study was to assess the in vitro efficacy of five essential oils against adults of Pediculus humanus capitis using a contact filter paper toxicity bioassay. The chemical composition of the essential oils from wild bergamot, clove, lavender, tea tree, and Yunnan verbena was analyzed by gas chromatography-mass spectrometry. All treatments and controls were replicated three times on separate occasions over a period of 11 months. In all, 1239 living lice were collected from the scalp of 51 subjects, aged from 1 to 69 years. Clove oil, diluted either in coco oil or sunflower oil, demonstrated the best adulticidal activity, reaching > 90% mortality within 2 h in lice submitted to a 30-min contact. Yunnan verbena oil diluted in coco oil showed also a significant efficacy. Other essential oils showed a lower efficacy. The oil's major component(s) differed according to the tested oils and appeared chemically diverse. In the case of clove oil, the eugenol appeared as the main component. This study confirmed the potential interest of some of the essential oils tested, but not all, as products to include possibly in a pediculicidal formulation.


Assuntos
Inseticidas/administração & dosagem , Infestações por Piolhos/tratamento farmacológico , Óleos Voláteis/administração & dosagem , Pediculus/efeitos dos fármacos , Adolescente , Adulto , Idoso , Animais , Criança , Pré-Escolar , China , Citrus/química , Avaliação Pré-Clínica de Medicamentos , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Lactente , Inseticidas/química , Lavandula/química , Infestações por Piolhos/parasitologia , Masculino , Melaleuca/química , Pessoa de Meia-Idade , Óleos Voláteis/química , Pediculus/fisiologia , Extratos Vegetais/química , Óleos de Plantas/administração & dosagem , Óleos de Plantas/química , Syzygium/química , Adulto Jovem
6.
Nature ; 465(7299): 788-92, 2010 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-20473285

RESUMO

Despite a rapidly-growing scientific and clinical brain imaging literature based on functional magnetic resonance imaging (fMRI) using blood oxygenation level-dependent (BOLD) signals, it remains controversial whether BOLD signals in a particular region can be caused by activation of local excitatory neurons. This difficult question is central to the interpretation and utility of BOLD, with major significance for fMRI studies in basic research and clinical applications. Using a novel integrated technology unifying optogenetic control of inputs with high-field fMRI signal readouts, we show here that specific stimulation of local CaMKIIalpha-expressing excitatory neurons, either in the neocortex or thalamus, elicits positive BOLD signals at the stimulus location with classical kinetics. We also show that optogenetic fMRI (of MRI) allows visualization of the causal effects of specific cell types defined not only by genetic identity and cell body location, but also by axonal projection target. Finally, we show that of MRI within the living and intact mammalian brain reveals BOLD signals in downstream targets distant from the stimulus, indicating that this approach can be used to map the global effects of controlling a local cell population. In this respect, unlike both conventional fMRI studies based on correlations and fMRI with electrical stimulation that will also directly drive afferent and nearby axons, this of MRI approach provides causal information about the global circuits recruited by defined local neuronal activity patterns. Together these findings provide an empirical foundation for the widely-used fMRI BOLD signal, and the features of of MRI define a potent tool that may be suitable for functional circuit analysis as well as global phenotyping of dysfunctional circuitry.


Assuntos
Encéfalo/citologia , Encéfalo/efeitos da radiação , Imageamento por Ressonância Magnética , Vias Neurais/efeitos da radiação , Neurônios/metabolismo , Neurônios/efeitos da radiação , Potenciais de Ação/efeitos da radiação , Anestesia , Animais , Encéfalo/anatomia & histologia , Encéfalo/irrigação sanguínea , Circulação Cerebrovascular/efeitos da radiação , Clorófitas , Medições Luminescentes , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Córtex Motor/irrigação sanguínea , Córtex Motor/citologia , Córtex Motor/metabolismo , Córtex Motor/efeitos da radiação , Neurônios/classificação , Neurônios/citologia , Oxigênio/sangue , Oxigênio/metabolismo , Estimulação Luminosa , Ratos , Rodopsina/genética , Rodopsina/metabolismo , Rodopsina/efeitos da radiação , Tálamo/irrigação sanguínea , Tálamo/citologia , Tálamo/metabolismo , Tálamo/efeitos da radiação
7.
Malar J ; 14: 278, 2015 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-26178656

RESUMO

BACKGROUND: The three members of the ring-infected erythrocyte surface antigen (RESA) proteins family share high sequence homologies, which impair the detection and assignment to one or another protein of some pathogenic processes inherent to Plasmodium falciparum malaria. The present study was intended to determine if the antibody and inflammatory responses of children living in a malaria-endemic area varied depending on the RESA-1, RESA-2 or RESA-3 proteins and the severity of the disease, two groups of severe and uncomplicated malaria cases being considered. METHODS: Two synthetic peptides representing predicted B cell epitopes were designed per RESA protein, all located outside of the 3' and 5' repetition blocks, in order to allow an antibody detection specific of each member of the family. Recombinant rRESA-1B and rRESA-3B proteins were also engineered. Two groups of Beninese children admitted to hospital in 2009 for either uncomplicated or severe malaria were compared for their plasma levels of IgG specifically recognizing each recombinant RESA protein or synthetic peptide, and for their plasma inflammatory cytokine levels (IFN-γ, TNF-α and IL-10), taking into account host and parasite genetic factors. RESULTS: The absence of IgG cross-reactivity between rRESA proteins and their protein carrier as well as between each RESA peptide and a non-epitopic RESA control peptide validated the use of the engineered recombinant proteins and peptides for the measurement of plasma IgG. Taking into account age, fever duration and parasitaemia, a multiple logistic regression performed on children clustered according to their antibody responses' profiles concluded to an increased risk of severe malaria for P2 (representative of RESA-1) responders (P = 0.007). Increased IL-10 plasma levels were found in children harbouring multiclonal P. falciparum infections on the basis of the T1526G resa2 gene polymorphism (P = 0.004). CONCLUSIONS: This study provided novel tools to dissect the seroreactivity against the three members of the RESA protein family and to describe its relation to protection against malaria. It suggested the measurement of plasma antibodies raised against specific peptides to serve as predictive immunologic markers for disease severity. Lastly, it reinforced previous observations linking the T1526G resa2 gene mutation to severe malaria.


Assuntos
Anticorpos Antiprotozoários/imunologia , Malária Falciparum/imunologia , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Anticorpos Antiprotozoários/sangue , Benin/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Citocinas/sangue , Citocinas/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Lactente , Malária Falciparum/epidemiologia , Masculino , Proteínas Recombinantes/imunologia
8.
Emerg Infect Dis ; 20(10): 1637-44, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25272023

RESUMO

Numerous studies have indicated a strong association between amplification of the multidrug resistance-1 gene and in vivo and in vitro mefloquine resistance of Plasmodium falciparum. Although falciparum infection usually is not treated with mefloquine, incorrect diagnosis, high frequency of undetected mixed infections, or relapses of P. vivax infection triggered by P. falciparum infections expose non-P. falciparum parasites to mefloquine. To assess the consequences of such unintentional treatments on P. vivax, we studied variations in number of Pvmdr-1 (PlasmoDB accession no. PVX_080100, NCBI reference sequence NC_009915.1) copies worldwide in 607 samples collected in areas with different histories of mefloquine use from residents and from travelers returning to France. Number of Pvmdr-1 copies correlated with drug use history. Treatment against P. falciparum exerts substantial collateral pressure against sympatric P. vivax, jeopardizing future use of mefloquine against P. vivax. A drug policy is needed that takes into consideration all co-endemic species of malaria parasites.


Assuntos
Resistência a Medicamentos/efeitos dos fármacos , Malária Vivax/parasitologia , Mefloquina/uso terapêutico , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Plasmodium vivax/efeitos dos fármacos , Proteínas de Protozoários/metabolismo , Camboja/epidemiologia , Guiana Francesa/epidemiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Madagáscar/epidemiologia , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Malária Vivax/epidemiologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Plasmodium falciparum/efeitos dos fármacos , Proteínas de Protozoários/genética , Sudão/epidemiologia
9.
Nat Prod Res ; : 1-6, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38770986

RESUMO

Candida species are responsible for the most common fungal infections worldwide. We studied the in vitro antifungal activity of a large panel of essential oils (EOs) against various Candida species. The EOs activity against Candida spp. was tested using a gradient microdilution assay ranging from 4% to 0.008% (v/v). After a preliminary screening including 31 EOs, seven selected EOs were tested against 13 clinical isolates and four reference strains belonging to six Candida species. Cinnamomum zeylanicum and Cymbopogon giganteus EOs exhibited the best antifungal activity against all clinical and reference strains, with MIC ranges of 0.015%-0.25% (v/v). EOs from Litsea citrata, Backhousia citriodora and Ocimum sanctum presented MIC ranges of 0.03%-0.5% (v/v). The antifungal efficacy of EOs was independent of the susceptibility of Candida strains to usual antifungal agents. These EOs could have a promising antifungal action.

10.
Malar J ; 12: 35, 2013 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-23351608

RESUMO

BACKGROUND: Chloroquine (CQ) was the main malaria therapy worldwide from the 1940s until the 1990s. Following the emergence of CQ-resistant Plasmodium falciparum, most African countries discontinued the use of CQ, and now promote artemisinin-based combination therapy as the first-line treatment. This change was generally initiated during the last decade in West and Central Africa. The aim of this study is to describe the changes in CQ susceptibility in this African region, using travellers returning from this region as a sentinel system. METHODS: The study was conducted by the Malaria National Reference Centre, France. The database collated the pfcrtK76T molecular marker for CQ susceptibility and the in vitro response to CQ of parasites from travellers' isolates returning from Senegal, Mali, Ivory Coast or Cameroon. As a proxy of drug pressure, data regarding CQ intake in febrile children were collated for the study period. Logistic regression models were used to detect trends in the proportions of CQ resistant isolates. RESULTS: A total of 2874 parasite isolates were genotyped between 2000-2011. The prevalence of the pfcrt76T mutant genotype significantly decreased for Senegal (from 78% to 47%), Ivory Coast (from 63% to 37%), Cameroon (from 90% to 59%) and remained stable for Mali. The geometric mean of the 50% inhibitory concentration (IC50) of CQ in vitro susceptibility and the proportion of resistant isolates (defining resistance as an IC50 value > 100 nM) significantly decreased for Senegal (from 86 nM (59%) to 39 nM (25%)), Mali (from 84 nM (50%) to 51 nM (31%)), Ivory Coast (from 75 nM (59%) to 29 nM (16%)) and Cameroon (from 181 nM (75%) to 51 nM (37%)). Both analyses (molecular and in vitro susceptibility) were performed for the 2004-2011 period, after the four countries had officially discontinued CQ and showed an accelerated decline of the resistant isolates for the four countries. Meanwhile, CQ use among children significantly deceased in this region (fixed effects slope = -0.3, p < 10-3). CONCLUSIONS: An increase in CQ susceptibility following official withdrawal of the drug was observed in travellers returning from West and Central African countries. The same trends were observed for molecular and in vitro analysis between 2004-2011 and they correlated to the decrease of the drug pressure.


Assuntos
Antimaláricos/uso terapêutico , Cloroquina/uso terapêutico , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Adolescente , Adulto , África Central , África Ocidental , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Resistência a Medicamentos , Feminino , Genótipo , Humanos , Lactente , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Testes de Sensibilidade Parasitária , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Viagem , Adulto Jovem
11.
Antimicrob Agents Chemother ; 56(2): 863-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22123682

RESUMO

Molecular investigations performed following the emergence of sulfadoxine-pyrimethamine (SP) resistance in Plasmodium falciparum have allowed the identification of the dihydrofolate reductase (DHFR) enzyme as the target of pyrimethamine. Although clinical cases of Plasmodium malariae are not usually treated with antifolate therapy, incorrect diagnosis and the high frequency of undetected mixed infections has probably exposed non-P. falciparum parasites to antifolate therapy in many areas. In this context, we aimed to assess the worldwide genetic diversity of the P. malariae dhfr gene in 123 samples collected in Africa and Asia, areas with different histories of SP use. Among the 10 polymorphic sites found, we have observed 7 new mutations (K55E, S58R, S59A, F168S, N194S, D207G, and T221A), which led us to describe 6 new DHFR proteins. All isolates from African countries were classified as wild type, while new mutations and haplotypes were recognized as exclusive to Madagascar (except for the double mutations at nucleotides 341 and 342 [S114N] found in one Cambodian isolate). Among these nonsynonymous mutations, two were likely related to pyrimethamine resistance: S58R (corresponding to C59R in P. falciparum and S58R in Plasmodium vivax; observed in one Malagasy sample) and S114N (corresponding to S108N in P. falciparum and S117N in P. vivax; observed in three Cambodian samples).


Assuntos
Antimaláricos/farmacologia , Variação Genética , Mutação/efeitos dos fármacos , Plasmodium malariae/efeitos dos fármacos , Pirimetamina/farmacologia , Tetra-Hidrofolato Desidrogenase , África , Animais , Antimaláricos/uso terapêutico , Camboja , Combinação de Medicamentos , Resistência a Medicamentos/genética , Humanos , Madagáscar , Malária/tratamento farmacológico , Malária/parasitologia , Testes de Sensibilidade Parasitária , Plasmodium malariae/enzimologia , Plasmodium malariae/genética , Pirimetamina/uso terapêutico , Análise de Sequência de DNA , Sulfadoxina/farmacologia , Sulfadoxina/uso terapêutico , Tetra-Hidrofolato Desidrogenase/efeitos dos fármacos , Tetra-Hidrofolato Desidrogenase/genética
12.
Malar J ; 11: 128, 2012 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-22533816

RESUMO

BACKGROUND: Plasmodium falciparum exports proteins that remodel the erythrocyte membrane. One such protein, called Pf155/RESA (RESA1) contributes to parasite fitness, optimizing parasite survival during febrile episodes. Resa1 gene is a member of a small family comprising three highly related genes. Preliminary evidence led to a search for clues indicating the involvement of RESA2 protein in the pathophysiology of malaria. In the present study, cDNA sequence of resa2 gene was obtained from two different strains. The proportion of P. falciparum isolates having a non-stop T1526C mutation in resa2 gene was evaluated and the association of this genotype with severity of malaria was investigated. METHODS: Resa2 cDNAs of two different strains (a patient isolate and K1 culture adapted strain) was obtained by RT-PCR and DNA sequencing was performed to confirm its gene structure. The proportion of isolates having a T1526C mutation was evaluated using a PCR-RFLP methodology on groups of severe malaria and uncomplicated patients recruited in 1991-1994 in Senegal and in 2009 in Benin. RESULTS: A unique ORF with an internal translation stop was found in the patient isolate (Genbank access number : JN183870), while the K1 strain harboured the T1526C mutation (Genbank access number : JN183869) which affects the internal stop codon and restores a full length coding sequence. About 14% of isolates obtained from Senegal and Benin harboured mutant T1526C parasites. Some isolates had both wild and mutant resa alleles. The analysis excluding those mixed isolates showed that the resa2 T1526C mutation was found more frequently in severe malaria cases than in uncomplicated cases (p = 0.008). The association of the presence of the mutant allele and parasitaemia >4% was shown in multivariate analysis (p = 0.03) in the group of Beninese children. CONCLUSIONS: All T1526C mutant parasites theoretically have the ability to give rise to a full-length RESA2 protein. This study raises the hypothesis that the RESA2 protein could favour high-density infections. Other studies in various geographic settings and probably including more patients are now required to replicate these results and to answer the questions raised by these results.


Assuntos
Malária Falciparum/patologia , Malária Falciparum/parasitologia , Plasmodium falciparum/genética , Plasmodium falciparum/patogenicidade , Mutação Puntual , Proteínas de Protozoários/genética , Fatores de Virulência/genética , Adolescente , Adulto , Animais , Benin , Criança , Pré-Escolar , Análise Mutacional de DNA , DNA Complementar/química , DNA Complementar/genética , DNA de Protozoário/química , DNA de Protozoário/genética , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Polimorfismo de Fragmento de Restrição , Proteínas de Protozoários/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Senegal , Análise de Sequência de DNA , Fatores de Virulência/metabolismo , Adulto Jovem
13.
J Am Acad Dermatol ; 67(6): 1143-50, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22627039

RESUMO

BACKGROUND: Treatment of head lice infestation relies on the application of topical insecticides. Overuse of these products has led to the emergence of resistance to pyrethroids and malathion worldwide. Permethrin resistance in head lice is mostly conferred by the knockdown resistance (kdr) trait. OBJECTIVE: To evaluate the occurrence of permethrin- and malathion-resistant head lice in Paris. METHODS: A prospective survey was conducted in 74 elementary schools. Live lice collected on schoolchildren were randomly selected and submitted to ex vivo bioassays or underwent individual DNA extraction. A fragment of kdr-like gene was amplified and compared with wild-type sequences. RESULTS: Live head lice were detected in 574 children. Ex vivo assays showed no surviving lice after a 1-hour contact with malathion while most lice died after a 1-hour exposure to permethrin and piperonyl butoxide (85.7%, 95% confidence interval [CI]: 83.9-87.5). Among the 670 lice with workable DNA sequences, 661 lice (98.7%, 95% CI 97.7-99.3) had homozygous kdr mutations. LIMITATIONS: The findings of this large-scale survey of the occurrence of insecticide-resistant head lice indicated a major insecticide pressure in the study population, but it was not sufficient to draw conclusions about other populations. The presence of T917I-L920F mutations in kdr gene may not correlate with treatment failure in prospective studies. CONCLUSION: The high occurrence of kdr mutant allele suggests that insecticide resistance was already strongly established in the studied population. This finding must be interpreted with caution as it may not be predictive of treatment failure.


Assuntos
Inseticidas/uso terapêutico , Infestações por Piolhos/tratamento farmacológico , Malation/uso terapêutico , Pediculus/efeitos dos fármacos , Permetrina/uso terapêutico , Animais , Criança , Feminino , Humanos , Resistência a Inseticidas , Masculino , Pediculus/genética , Estudos Prospectivos
14.
Sci Rep ; 12(1): 7176, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35504935

RESUMO

The mite Sarcoptes scabiei is responsible for scabies, a pruritic and contagious skin disease in humans. S. scabiei is also responsible for mange in a wide range of animal species. The treatment of S. scabiei infection is hampered by an under-effectiveness of the few available drugs. The objective of this work was to evaluate the in vitro acaricide activity of a large number of plant essential oils (EOs) against S. scabiei. EOs were selected mainly on the basis of traditional treatments for dermatological infections in Madagascar. The sarcoptes originating from a porcine animal model were tested at concentrations ranging from 10 to 0.1%. The viability of sarcoptes was assessed by stereomicroscopic observation at 5 min, 15 min, 30 min, 45 min and then every hour until 6 h after treatment. Estimates of lethal time and lethal concentration producing 50% mortality were generated using a probit analysis. The survival curves were estimated using the Kaplan Meier method. A total of 31 EOs from different plants were tested. Cinnamomum zeylanicum (cinnamom) and Ocimum sanctum (tulsi) oils were the most active for all concentrations tested. They may be included in in vivo studies, in order to further assess their potential interest as topical treatments.


Assuntos
Acaricidas , Óleos Voláteis , Escabiose , Acaricidas/farmacologia , Animais , Óleos Voláteis/farmacologia , Óleos Voláteis/uso terapêutico , Óleos de Plantas/farmacologia , Sarcoptes scabiei , Escabiose/tratamento farmacológico , Suínos
15.
Emerg Infect Dis ; 17(5): 807-13, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21529388

RESUMO

Little is known about severe imported Plasmodium falciparum malaria in industrialized countries where the disease is not endemic because most studies have been case reports or have included <200 patients. To identify factors independently associated with the severity of P. falciparum, we conducted a retrospective study using surveillance data obtained from 21,888 P. falciparum patients in France during 1996-2003; 832 were classified as having severe malaria. The global case-fatality rate was 0.4% and the rate of severe malaria was ≈3.8%. Factors independently associated with severe imported P. falciparum malaria were older age, European origin, travel to eastern Africa, absence of chemoprophylaxis, initial visit to a general practitioner, time to diagnosis of 4 to 12 days, and diagnosis during the fall-winter season. Pretravel advice should take into account these factors and promote the use of antimalarial chemoprophylaxis for every traveler, with a particular focus on nonimmune travelers and elderly persons.


Assuntos
Malária Falciparum/epidemiologia , Vigilância da População , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , França/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Viagem , Adulto Jovem
16.
Malar J ; 10: 283, 2011 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-21951962

RESUMO

BACKGROUND: Recently, Plasmodium falciparum parasites bearing Pfdhfr I164L single mutation were found in Madagascar. These new mutants may challenge the use of antifolates for the intermittent preventive treatment of malaria during pregnancy (IPTp). Assays with transgenic bacteria suggested that I164L parasites have a wild-type phenotype for pyrimethamine but it had to be confirmed by testing the parasites themselves. METHODS: Thirty Plasmodium falciparum clinical isolates were collected in 2008 in the south-east of Madagascar. A part of Pfdhfr gene encompassing codons 6 to 206 was amplified by PCR and the determination of the presence of single nucleotide polymorphisms was performed by DNA sequencing. The multiplicity of infection was estimated by using an allelic family-specific nested PCR. Isolates that appeared monoclonal were submitted to culture adaptation. Determination of IC(50s) to pyrimethamine was performed on adapted isolates. RESULTS: Four different Pfdhfr alleles were found: the 164L single mutant-type (N = 13), the wild-type (N = 7), the triple mutant-type 51I/59R/108N (N = 9) and the double mutant-type 108N/164L (N = 1). Eleven out 30 (36.7%) of P. falciparum isolates were considered as monoclonal infection. Among them, five isolates were successfully adapted in culture and tested for pyrimethamine in vitro susceptibility. The wild-type allele was the most susceptible with a 50% inhibitory concentration (IC(50)) < 10 nM. The geometric mean of IC(50) of the three I164L mutant isolates was 6-fold higher than the wild-type with 61.3 nM (SD = 3.2 nM, CI95%: 53.9-69.7 nM). These values remained largely below the IC(50) of the triple mutant parasite (13,804 nM). CONCLUSION: The IC(50)s of the I164L mutant isolates were significantly higher than those of the wild-type (6-fold higher) and close from those usually reported for simple mutants S108N (roughly10-fold higher than wild type). Given the observed values, the determination of IC(50)s directly on parasites did not confirm what has been found on transgenic bacteria. The prevalence increase of the Pfdhfr I164L single mutant parasite since 2006 could be explained by the selective advantage of this allele under sulphadoxine-pyrimethamine pressure. The emergence of highly resistant alleles should be considered in the future, in particular because an unexpected double mutant-type allele S108N/I164L has been already detected.


Assuntos
Antimaláricos/farmacologia , Resistência a Medicamentos , Mutação de Sentido Incorreto , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Pirimetamina/farmacologia , Tetra-Hidrofolato Desidrogenase/genética , Adulto , Substituição de Aminoácidos , DNA de Protozoário/química , DNA de Protozoário/genética , Feminino , Humanos , Concentração Inibidora 50 , Madagáscar , Malária Falciparum/parasitologia , Testes de Sensibilidade Parasitária , Plasmodium falciparum/isolamento & purificação , Reação em Cadeia da Polimerase , Gravidez , Análise de Sequência de DNA
17.
J Med Entomol ; 48(1): 73-5, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21337951

RESUMO

Resistance of head lice to pyrethroids induces difficult therapeutic problems. Previous studies demonstrated that this resistance was present in a French urban area, but its prevalence needed to be more precisely evaluated in terms of genotyping lice collected from more infested children over a certain period of time. We monitored the presence of the head lice kdr-like haplotype of the voltage-gated sodium channel alpha-subunit gene in schoolchildren seen three times on a 6-wk period. The prevalence of pediculosis was 2.39% (n = 1551). Genotyped lice (n = 167) were homozygous resistant in all but one pupil. The high frequency of the mutant haplotype (0.93) advocated for the abandonment of pyrethroid insecticides in this area and for the consideration of other treatment options.


Assuntos
Resistência a Inseticidas/genética , Inseticidas , Pediculus/genética , Piretrinas , Canais de Sódio/genética , Animais , Criança , Pré-Escolar , Feminino , França , Haplótipos , Humanos , Inseticidas/uso terapêutico , Infestações por Piolhos/tratamento farmacológico , Masculino , Mutação , Pediculus/efeitos dos fármacos , Piretrinas/uso terapêutico
18.
Antimicrob Agents Chemother ; 54(6): 2323-9, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20308388

RESUMO

The combination of sulfadoxine-pyrimethamine is recommended for use as intermittent preventive treatment of malaria during pregnancy and is deployed in Africa. The emergence and the spread of resistant parasites are major threats to such an intervention. We have characterized the Plasmodium falciparum dhfr (pfdhfr) haplotypes and flanking microsatellites in 322 P. falciparum isolates collected from the Comoros Islands and Madagascar. One hundred fifty-six (48.4%) carried the wild-type pfdhfr allele, 19 (5.9%) carried the S108N single-mutation allele, 30 (9.3%) carried the I164L single-mutation allele, 114 (35.4%) carried the N51I/C59R/S108N triple-mutation allele, and 3 (1.0%) carried the N51I/C59R/S108N/I164L quadruple-mutation allele. Microsatellite analysis showed the introduction from the Comoros Islands of the ancestral pfdhfr triple mutant allele of Asian origin and its spread in Madagascar. Evidence for the emergence on multiple occasions of the I164L single-mutation pfdhfr allele in Madagascar was also obtained. Thus, the conditions required to generate mutants with quadruple mutations are met in Madagascar, representing a serious threat to current drug policy.


Assuntos
Genes de Protozoários , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Alelos , Animais , Comores , Repetições de Dinucleotídeos , Resistência a Medicamentos/genética , Feminino , Haplótipos , Humanos , Madagáscar , Malária Falciparum/complicações , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Malária Falciparum/prevenção & controle , Mutação , Plasmodium falciparum/isolamento & purificação , Gravidez , Complicações Parasitárias na Gravidez/tratamento farmacológico , Complicações Parasitárias na Gravidez/parasitologia , Complicações Parasitárias na Gravidez/prevenção & controle , Proteínas de Protozoários/genética , Tetra-Hidrofolato Desidrogenase/genética
19.
Scand J Infect Dis ; 42(1): 22-32, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19883158

RESUMO

Malaria remains a major health problem in Madagascar. Over past decades, the burden of malarial disease has fluctuated over time, partly in line with the successes and failures of antimalarial policy. In the 1950s and 1960s, a sharp decline in malaria transmission was observed in the central highlands due to indoor spraying with DDT and to the massive use of chloroquine by the population. Following this, the discontinuation of the 'nivaquinization' policy was followed by devastating outbreaks in the central highlands in the 1980s. Currently, the rate of in vitro chloroquine-resistant Plasmodium falciparum isolates does not exceed 5%. This figure appears disconnected from the high level of clinical treatment failure (near 40%). pfcrt mutant isolates are found in less than 1% of isolates on the Island. Conversely, pfmdr1 mutant isolates are found in more than 60% of isolates and may be responsible for the bulk of resistance to chloroquine in Madagascar. Other antimalarials remain generally effective in Madagascar. Recent clinical and in vitro data support the complete efficacy of the combination artesunate-amodiaquine in Madagascar. As such, this artemisinin combination therapy should play a central role in the control and possible elimination of P. falciparum malaria in Madagascar


Assuntos
Antimaláricos/farmacologia , Resistência a Medicamentos , Malária Falciparum/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Animais , Humanos , Madagáscar , Plasmodium falciparum/isolamento & purificação
20.
Artigo em Inglês | MEDLINE | ID: mdl-32630433

RESUMO

The bed bugs (Cimex lectularius and C. hemipterus) have undergone a significant resurgence worldwide since the 1990s. A compilation of findings from a database, including 2650 scientific publications from seven major medical databases, allowed us to document main evolutionary events, from fossil evidence, dating from 11,000 years ago, until the present that has led to the current worldwide expansion of Cimicid species. We present the hypotheses on the possible dispersion pathways of bed bugs in light of the major historical and evolutionary events. A detailed classification of the Cimicidae family and finally, an illustrative map displaying the current distribution of known Cimex species in each geographical ecozone of Asia, Europe, Africa, the Americas, and Australia are presented.


Assuntos
Percevejos-de-Cama , Filogenia , África , Animais , Ásia , Austrália , Percevejos-de-Cama/classificação , Europa (Continente) , Humanos , Estados Unidos
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