RESUMO
An oil-based formulation of the EG95 vaccine to protect grazing animals against infection with Echinococcus granulosus was formulated in Argentina. The efficacy of the vaccine was monitored by serology in sheep and llama (Lama glama) and was compared to the serology in sheep previously published using a QuilA-adjuvanted vaccine. Long-term efficacy was also tested in sheep by challenging with E. granulosus eggs of the G1 strain 4 years after the beginning of the trial. The serological results for both sheep and llama were similar to those described previously, except that there was a more rapid response after the first vaccination. A third vaccination given after 1 year resulted in a transient boost in serology that lasted for about 12 months, which was similar to results previously described. Sheep challenged after 4 years with three vaccinations presented 84·2% reduction of live cysts counts compared with control group, and after a fourth vaccination prior to challenge, this reduction was 94·7%. The oil-based vaccine appeared to be bio-equivalent to the QuilA vaccine.
Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Helmintos/imunologia , Camelídeos Americanos/imunologia , Equinococose/veterinária , Echinococcus granulosus/imunologia , Proteínas de Helminto/imunologia , Doenças dos Ovinos/prevenção & controle , Ovinos/imunologia , Vacinação/veterinária , Adjuvantes Imunológicos , Animais , Argentina , Equinococose/imunologia , Equinococose/parasitologia , Imunização Secundária , Saponinas de Quilaia/imunologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia , Vacinas/imunologiaRESUMO
The origin of agriculture was a signal development in human affairs and as such has occupied the attention of scholars from the natural and social sciences for well over a century. Historical studies of climate and vegetation are closely associated with crop plant evolution because they can reveal the ecological contexts of plant domestication together with the antiquity and effects of agricultural practices on the environment. In this article, we present paleoecological evidence from three lakes and a swamp located in the Central Balsas watershed of tropical southwestern Mexico that date from 14,000 B.P. to the modern era. [Dates expressed in B.P. years are radiocarbon ages. Calibrated (calendar) ages, expressed as cal B.P., are provided for dates in the text.] Previous molecular studies suggest that maize (Zea mays L.) and other important crops such as squashes (Cucurbita spp.) were domesticated in the region. Our combined pollen, phytolith, charcoal, and sedimentary studies indicate that during the late glacial period (14,000-10,000 B.P.), lake beds were dry, the climate was cooler and drier, and open vegetational communities were more widespread than after the Pleistocene ended. Zea was a continuous part of the vegetation since at least the terminal Pleistocene. During the Holocene, lakes became important foci of human activity, and cultural interference with a species-diverse tropical forest is indicated. Maize and squash were grown at lake edges starting between 10,000 and 5,000 B.P., most likely sometime during the first half of that period. Significant episodes of climatic drying evidenced between 1,800 B.P. and 900 B.P. appear to be coeval with those documented in the Classic Maya region and elsewhere, showing widespread instability in the late Holocene climate.
Assuntos
Meio Ambiente , Áreas Alagadas , Clima , Ecossistema , Fósseis , Geografia , Sedimentos Geológicos , História Antiga , Humanos , México , PólenRESUMO
The type strain Bacillus thuringiensis var. bolivia (serotype H63), isolated from the Bolivian high valleys, has been characterized at different levels. Its parasporal crystal has an unusual shape and it is composed of a protein of 155 kDa which shows two bands of 75 and 80 kDa after activation. Analysis by PCR shows the presence of cry1 genes, and amplification with specific primers gave products for cry1 E, cry1 D, cry4 A and cry4 B with sizes different to those expected. Immunoblotting tests showed positive reaction for Cry1 E, Cry3 A, Cry4 A and Cry11 A crystal proteins. The plasmid pattern revealed two large and two small plasmids. Toxicity tests were performed against 14 insects and a slight toxicity was found against Plutella xylotella and Trichoplusia ni.
Assuntos
Bacillus thuringiensis/classificação , Bacillus thuringiensis/isolamento & purificação , Besouros/microbiologia , Animais , Bacillus thuringiensis/ultraestrutura , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/genética , Proteínas de Bactérias/toxicidade , Toxinas Bacterianas/genética , Toxinas Bacterianas/toxicidade , Western Blotting , Bolívia , Eletroforese em Gel de Poliacrilamida , Endotoxinas/genética , Endotoxinas/toxicidade , Proteínas Hemolisinas , Larva/microbiologia , Microscopia Eletrônica de Varredura , Plasmídeos/genéticaRESUMO
Experimental vaccine trials against hydatid disease have been undertaken in sheep using the EG95 recombinant vaccine. Challenge infection was with viable Echinococcus granulosus eggs obtained from a New Zealand isolate (dog/sheep cycle), an Australian isolate (dingo/wallaby cycle) and an Argentine isolate (dog/sheep cycle). Vaccination with EG95 conferred a high degree of protection against challenge with all three parasite isolates (protection range 96-100%). Taken together, the trials demonstrated that 86% of vaccinated sheep were completely free of viable hydatid cysts when examined approximately 1 year after challenge infection. Vaccination reduced the number of viable cysts by 99.3% compared with unvaccinated controls. These results suggest that the EG95 vaccine could have wide applicability as a new tool for use in hydatid control campaigns.
Assuntos
Antígenos de Helmintos/uso terapêutico , Equinococose/veterinária , Doenças dos Ovinos/prevenção & controle , Vacinas Sintéticas/uso terapêutico , Animais , Antígenos de Helmintos/imunologia , Argentina , Austrália , Cães , Equinococose/imunologia , Equinococose/prevenção & controle , Equinococose/transmissão , Echinococcus/imunologia , Feminino , Estudos Longitudinais , Macropodidae/parasitologia , Masculino , Contagem de Ovos de Parasitas/veterinária , Ovinos , Doenças dos Ovinos/parasitologia , Especificidade da Espécie , Vacinas Sintéticas/imunologiaRESUMO
Rarely observed in the wild, the existence of the Andean mountain cat (Oreailurus jacobita) has been established based on only 3 skulls and 14 museum skins. The Andean mountain cat's evolutionary relationship to other felids based on morphological characters is largely contradictory, with evidence aligning it with South American small spotted cats (ocelot lineage) or alternatively with pantherine lineage felids. Here we describe the phylogenetic distinctiveness and placement of the Andean mountain cat using DNA extracted from pieces of nine independent pelt specimens, including one confiscated from a trapper in 1995. A phylogenetic analysis of DNA sequences from three rapidly evolving mitochondrial genes (16S rRNA, NADH-5, and ATP-8) indicate that the Andean mountain cat is a distinct species belonging to the ocelot lineage. Our findings suggest that the Andean mountain cat diverged from a common ancestor with the ocelot (Leopardus paradalis) and margay (L. wiedii) and exhibits moderate levels of genetic variation.
Assuntos
Evolução Biológica , Carnívoros/genética , DNA Mitocondrial/genética , Animais , Sequência de Bases , Evolução Molecular , Dados de Sequência Molecular , Filogenia , Homologia de Sequência do Ácido Nucleico , América do Sul , Especificidade da EspécieRESUMO
The results of a control program of hydatid disease in five jurisdictions of the Patagonian Region in Argentina are presented. The information is glossed in rates of infection in man (95 x 100,000 in 1988 and 15 x 100,000 in 1983), dogs (21.6% in 1983 and 3.1% in 1988) and sheep (16.6% in 1983 and 2.6% in 1988). Factors that condition the endemic situation of hydatidosis in the region are discussed.
Assuntos
Doenças do Cão/transmissão , Equinococose/transmissão , Animais , Argentina , Doenças do Cão/prevenção & controle , Cães , Equinococose/prevenção & controle , Humanos , Incidência , Praziquantel/uso terapêuticoRESUMO
In South America programs to control hydatidosis caused by Echinococcus granulosus include the active search for asymptomatic patients through population surveys for the detection of antibodies against arc 5 antigens using the double diffusion arc 5 test (DD5). Though simple to perform and highly specific, DD5 is not practical for population studies due to the time lapse between testing and receiving results. This work evaluates the application of an enzyme immunoassay to screen sera for subsequent processing using DD5. The efficiency of an enzyme immunoassay screening/DD5 confirmation scheme vs. DD5 alone was compared within the framework of a control program. A total of 5,839 sera from residents of endemic areas was processed and 47 hydatid patients were detected by both schemes. The proposed enzyme immunoassay identified all sera having antibody activity against arc 5 antigens detectable by DD5 and ruled out 95.3% of sera which tested by DD5 would have produced negative results.