RESUMEN
The objectives of this study were to investigate the molecular basis for Plasmodium falciparum resistance to chloroquine in isolates from the Brazilian Amazon and to identify polymorphisms in the pfmdr1 gene, codons 184, 1042, and 1246, the kappa and gamma regions of the cg2 gene, and the K76T mutation of the pfcrt gene, in order to calculate the distribution of polymorphism within each target gene, comparing samples from distinct geographic areas, using allele-specific polymerase chain reaction (PCR) for the pfmdr gene and PCR plus restriction fragment length polymorphism (RFLP) for the cg2 and pfcrt genes. The sample consisted of 40 human blood isolates, already collected and morphologically diagnosed as carriers of P. falciparum parasites, from four localities: Porto Velho in Rondonia State and Maraba, Itaituba, and Tailandia in Pará State. Distribution of P. falciparum in vitro chloroquine resistance in the isolates was 100 percent for pfmdr1, cg2 gamma region, and pfcrt, except for the polymorphism in the cg2 kappa region, which was not found.
O estudo foi desenvolvido para investigar a base molecular da resistência do Plasmodium falciparum à cloroquina em isolados da região Amazônica brasileira e identificar os polimorfismos nos códons TYR184PHE, ASN1042ASP e ASP1246TYR do gene pfmdr1, as regiões kappa e gamma do gene cg2 e a mutação K76T do gene pfcrt, a fim de determinar a distribuição percentual dos alelos de cada gene estudado, comparando amostras de áreas geográficas distintas, utilizando a reação em cadeia da polimerase (PCR) alelo-específica para o pfmdr1 e a PCR e o polimorfismo do comprimento do fragmento de restrição (RFLP) para os genes cg2 e pfcrt. A amostra foi constituída de quarenta isolados de sangue humano já coletados e microscopicamente diagnosticados com malária por P. falciparum das localidades de Porto Velho (Rondônia) e Marabá, Itaituba e Tailândia (Pará). A distribuição percentual da resistência in vitro do P. falciparum à cloroquina nas amostras estudadas foi de 100 por cento de resistência para os genes pfmdr1, região gamma do cg2 e pfcrt. O polimorfismo na região kappa do gene cg2 não foi encontrado nas amostras estudadas.
Asunto(s)
Humanos , Antimaláricos/farmacología , Cloroquina/farmacología , Plasmodium falciparum/genética , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Proteínas Protozoarias/genética , Resistencia a Medicamentos/genética , Brasil , Malaria Falciparum/parasitología , Plasmodium falciparum/parasitologíaRESUMEN
The objectives of this study were to investigate the molecular basis for Plasmodium falciparum resistance to chloroquine in isolates from the Brazilian Amazon and to identify polymorphisms in the pfmdr1 gene, codons 184, 1042, and 1246, the kappa and gamma regions of the cg2 gene, and the K76T mutation of the pfcrt gene, in order to calculate the distribution of polymorphism within each target gene, comparing samples from distinct geographic areas, using allele-specific polymerase chain reaction (PCR) for the pfmdr gene and PCR plus restriction fragment length polymorphism (RFLP) for the cg2 and pfcrt genes. The sample consisted of 40 human blood isolates, already collected and morphologically diagnosed as carriers of P. falciparum parasites, from four localities: Porto Velho in Rondonia State and Maraba, Itaituba, and Tailandia in Pará State. Distribution of P. falciparum in vitro chloroquine resistance in the isolates was 100% for pfmdr1, cg2 gamma region, and pfcrt, except for the polymorphism in the cg2 kappa region, which was not found.
Asunto(s)
Antimaláricos/farmacología , Cloroquina/farmacología , Resistencia a Medicamentos/genética , Mutación/genética , Plasmodium falciparum/genética , Proteínas Protozoarias/genética , Transportadoras de Casetes de Unión a ATP/genética , Animales , Brasil , Codón/genética , Marcadores Genéticos/genética , Humanos , Proteínas de Transporte de Membrana/genética , Plasmodium falciparum/efectos de los fármacos , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Polimorfismo de Longitud del Fragmento de RestricciónRESUMEN
We compared the serological phenotypic frequencies of ABO, MNSs, and Duffy in 417 blood donors and 309 malaria patients from four Brazilian Amazon areas. Our results suggest no correlation between ABO phenotype and malaria infection in all areas studied. We observed significant correlation between the S +s +, S +s -, and S -s + phenotypes and malaria infection in three areas. Some of the Duffy phenotypes showed significant correlation between donors and malaria patients in different areas. These data are an additional contribution to the establishment of differential host susceptibility to malaria.
Asunto(s)
Sistema del Grupo Sanguíneo ABO/genética , Sistema del Grupo Sanguíneo Duffy/genética , Sistema del Grupo Sanguíneo MNSs/genética , Malaria/sangre , Fenotipo , Adulto , Donantes de Sangre , Brasil , Estudios de Casos y Controles , Femenino , Humanos , MasculinoRESUMEN
This study aimed to evaluate the malaria epidemiological aspects in Santa Catarina State, Brazil, by using National Health Foundation data from 1996 to 2001. From 4,707 thick smears analyzed 5.5% were positive. Plasmodium vivax was found in 69.0%; Plasmodium falciparum in 25.6%, mixed infection with both in 5%, and Plasmodium malariae in only 0.4%. It was observed that 67.4% were heterochthonous cases and 32.6% autochthonous cases. In recent years, the incidence of heterochthonous cases has increased. The majority of these cases come from the Brazilian Amazon region and the remainder from African countries. However, the municipalities of Joinville, Blumenau, São Francisco do Sul and Florianópolis registered higher rates of autochthonous cases in 1996/1997. Control and epidemiological surveillance are necessary to prevent the reintroduction of Plasmodium in this region. It would be useful to investigate each epidemiological setting in order to prevent the reappearance of the disease in areas currently considered under control.
Asunto(s)
Malaria Falciparum/epidemiología , Malaria Vivax/epidemiología , Animales , Brasil/epidemiología , Humanos , IncidenciaRESUMEN
Este estudo objetiva conhecer o perfil epidemiológico da malária no Estado de Santa Catarina, analisando dados disponibilizados pela Fundaçäo Nacional de Saúde, relativos ao período de 1996/2001. Das 4.707 lâminas examinadas, 5,5 por cento evidenciaram-se positivas. As infecçöes por Plasmodium vivax foram 69 por cento, por Plasmodium falciparum 25,6 por cento, infecçöes mistas por ambos foram 5 por cento e, somente 0,4 por cento por Plasmodium malariae. Foi observado 67,4 por cento casos importados e 32,6 por cento casos autóctones. Nos últimos anos houve um aumento de casos importados. A maioria destes veio da regiäo Amazônica brasileira e o restante de países africanos. Identificou-se os municípios de Joinville, Blumenau, Säo Francisco do Sul e Florianópolis com maior número de autoctonia no biênio 1996/97. Medidas de controle e vigilância fazem-se necessárias, no sentido de prevenir a reintroduçäo do plasmódio, favorecendo a autoctonia. Será útil o mapeamento das áreas de risco, já que é contínua a expectativa de sua reemergência em áreas hoje consideradas sob controle
Asunto(s)
Humanos , Animales , Malaria , Brasil , Incidencia , MalariaRESUMEN
The aim of this study was to determine how different types of P. vivax affect clinical symptoms and parasitaemia clearance. Blood was collected from individuals from Pará State, Brazil. The patients were treated as chloroquine plus primaquine. P. vivax were typed daily till D7 and again on D30. Now we can confirm a previously reported correlation between P. vivax genotype and response to chloroquine. Clinical symptoms do not allow for objective identification of different P. vivax types in the Brazilian Amazon, since the VK247 and P. vivax-like have only been detected in mixed infections.
Asunto(s)
Antimaláricos/uso terapéutico , Cloroquina/uso terapéutico , Malaria Vivax/parasitología , Parasitemia/tratamiento farmacológico , Plasmodium vivax/genética , Primaquina/uso terapéutico , Animales , Brasil , Variación Genética , Genotipo , Humanos , Malaria Vivax/tratamiento farmacológico , Plasmodium vivax/efectos de los fármacosRESUMEN
The aim of this study was to determine how different types of P. vivax affect clinical symptoms and parasitaemia clearance. Blood was collected from individuals from Pará State, Brazil. The patients were treated as chloroquine plus primaquine. P. vivax were typed daily till D7 and again on D30. Now we can confirm a previously reported correlation between P. vivax genotype and response to chloroquine. Clinical symptoms do not allow for objective identification of different P. vivax types in the Brazilian Amazon, since the VK247 and P. vivax-like have only been detected in mixed infections