RESUMO
Leishmania panamensis and Leishmania guyanensis are two species of the subgenus Viannia that are genetically very similar. Both parasites are usually associated with cutaneous leishmaniasis, but also have the potential to cause the mucocutaneous form of the disease. In addition, the study of foci and consequently the identification of vectors and probable reservoirs involved in transmission require a correct differentiation between both species, which is important at epidemiological level. We explored the possibility of identifying these species by using restriction fragment length polymorphisms (RFLP) in the gene coding for heat-shock protein 70 (hsp70). Previously, an hsp70 PCR-RFLP assay proved to be very effective in differentiating other Leishmania species when HaeIII is used as restriction enzyme. Based on hsp70 sequences analysis, BccI was found to generate species-specific fragments that can easily be recognized by agarose gel electrophoresis. Using the analysis of biopsies, scrapings, and parasite isolates previously grouped in a cluster comprising both L. panamensis and L. guyanensis, we showed that our approach allowed differentiation of both entities. This offers the possibility not only for identification of parasites in biological samples, but also to apply molecular epidemiology in certain countries of the New World, where several Leishmania species could coexist.
Assuntos
Proteínas de Choque Térmico HSP70/genética , Leishmania guyanensis/genética , Reação em Cadeia da Polimerase/métodos , Humanos , Leishmania guyanensis/classificação , Leishmaniose Cutânea/genética , Leishmaniose Cutânea/parasitologia , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA , Especificidade da EspécieRESUMO
A genomic library of Leishmania amazonensis in expression vector of eukaryote cells (pEF1HisA, pEF1HisB, pEF1HisC) was prepared. Also two subgenomic libraries having each 500 clones approximately were created and BALB/c mice were immunized with 50 mg/0,1 mL of DNA from each. Two immunizations were administered intramuscularly at 15-day interval. Groups of control mice were immunized with DNA from empty plasmid pEF1His, with soluble parasite antigen (100 mg/0,1 mL) and saline solution. The size of lesions was measured for 12 weeks and at the end of the experiment, the parasite load at lesion sites was determined by plaque microtitration method. In mice immunized with subgenomic library DNAI and with soluble antigens,the size of lesions was controlled, which reached an statistical difference (p< 0,05) in relation to the rest of groups whose lesions increased. The parasite load found in lesion sites confirmed the previous results; the number of promastigots was significantly lower in those mice already protected. It was concluded that in subgenomic library DNA1 there should be genes or gene fragments whose in vivo expression induces protective immune response against the challenge in the murine model used.
Assuntos
Biblioteca Genômica , Imunização , Leishmania mexicana/genética , Leishmania mexicana/imunologia , Leishmaniose/prevenção & controle , Animais , Camundongos , Camundongos Endogâmicos BALB CRESUMO
In a study conducted in the province of Cienfuegos, it was proved by using immunological and biomolecular tools that intestina amebiasis in that province was an overdimensioned health problem. A survey on knowledge, perceptions and practices applied to those physicians related to the diagnosis, treatment and control of this parasitosis showed that the overdimensioning may be associated with an inadequate perception of the problem and with a marked lack of knowledge about important aspects of this entity. To contribute to the solution of the ovedimensioning and of its consequences, a set of actions were taken in that province. After a year, a second survey was done, whose results are published in this document, allowing to know about a significant improvement of the surveyed in almost all the evaluated cognitive and perceptual aspects (6.73 and 11.23 means of correct answers before and after the intervention, respectively).
Assuntos
Disenteria Amebiana , Conhecimentos, Atitudes e Prática em Saúde , Padrões de Prática Médica , Disenteria Amebiana/diagnóstico , Disenteria Amebiana/terapia , Educação Médica Continuada , Humanos , Inquéritos e QuestionáriosRESUMO
DNA from a genomic library of Leishmania amazonensis and from pcDNA3 plasmid were used to immunize BALB/c mice. Three immunizations at two weeks intervals were done, with 50µg/0.1ml of DNA. A control group was also injected with the same volume of saline solution. Afterward, all mice were challenged with infective promastigotes of the parasite, and the development of lesions was followed during 16 weeks by dorsoventral measures of the footpad. Mice previously immunized with the genomic library were capable of controlling lesions at a significant level, with major significance between 9 and 13 weeks post challenge.
Assuntos
Humanos , Vacinas de DNA , Leishmania , Biblioteca GenômicaRESUMO
Three studies were conducted in Cienfuegos province to prove that intestinal amebiasis in Cuba could be an overestimated health problem. The first two studies showed two components of this overestimation: microscopical overdiagnosis and lack of knowledge about Entamoeba dispar, a non-pathogenic species, in most cases in which microscopical examination was correct. This paper reported the third study that showed the third component: the wrong belief that Entamoeba histolytica is resistant to metronidazole. Thirty-five individuals infected with one or both species of E-histolytica-E. dispar combination were given metronidazole at a dose of 250 mg three times daily for 10 days. Stool samples taken immediately after the treatment were tested by ENZYMEBA to detect one or both species and by a multiplex polymerase chain reaction procedure to determine the existing species. The results of these assays revealed that E. histolytica infection disappeared in all the cases, therefore, we may conclude that in Cienfuegos province and probably in the rest of the country, metronidazol remains an effective drug in the treatment of intestinal amebiasis