Doutorado em Medicina Tropical e Saúde Pública (IPTSP)
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Item Caracterização morfológica, molecular e biológica de fungos patogênicos a invertebrados dos Cerrados de Goiás(Universidade Federal de Goiás, 2010-02-23) ROCHA, Luiz Fernando Nunes; KIPNIS, André; http://lattes.cnpq.br/4434965360286741; LUZ, Wolf Christian; http://lattes.cnpq.br/1104009511235835The high biodiversity of fungi pathogenic to invertebrates and their potential to control pests until today not well known emphasize the importance to look for new effective species and strains. The Cerrado is considered one of the hotspots of biodiversity and little is known about the occurrence and the potential of fungi pathogenic to invertebrates found in this biome. In the present study a survey of fungi was carried out in different areas of the Cerrado of Goiás. Samples of soil, slurry, water and moribund or dead insects were collected for isolation of fungi. Vectors of medical importance such as triatomines (Triatoma infestans and Rhodnius neglectus), mosquitoes (Aedes aegypti and Culex quinquefasciatus), ticks (Riphicephalus (Boophilus) microplus) and snails (Biomphalaria glabrata) were used as baits for isolation of fungi. After isolation fungi were morphologically identified and included in the collection ofInstitute of Tropical Pathology and Public Health, Federal University of Goiás. Some isolates of Evlachovaea and Metarhizium were molecularly characterized and activity tested against T. infestans. A total of 561 samples of soil (440), slurry (106) and water (15) was collected in different areas of Goiás State. Concerning samples collected at Fazenda Santa Branca, 68 isolates of pathogenic fungi were obtained and identified as belonging to the genera Aspergillus, Beauveria, Cladosporium, Evlachovaea, Fusarium, Gliocladium, Isaria,Lecanicillium, Metarhizium, Paecilomyces, Pochonia and Trichoderma. An total of 106 isolates of Metarhizium spp. and 6 of Evlachovaea spp. were sampled in other areas, being 65isolates of Metarhizium and 1 of Evlachovaea from the Ema National Park, 33 and 1 from the Northern portion of Goiás state, and 8 and 4 from the Silvânia National Forest, respectively.Most fungi were isolated from soils using triatomines as baits. Fungi from genera Aschersonia, Batkoa, Beauveria, Cordyceps, Evlachovaea, Fusarium, Lecanicillium, Pandora and Torrubiella were isolated from mycosed cadavers. All tested isolates of Metarhizium spp. and Evlachovaea spp. induced high mortality of T. infestans in relative humidity (RH) close to saturation. The lowest values for lethal time of 90% were 6.6 d (6.3 7.1 d; M. robertsii IP 34)and 7.1 d (6.7 7.8 d; Evlachovaea IP 141), after treatment of T. infestans and exposure to RH> 98%. The lethal concentration to obtain 50% mortality (LC50) of IP 34 was 2.8x103 (C.I. 4.4x102-4.6x103) and the LC90 was 7.2x103 (C.I. 4.4x103-6.4x105) CFU/cm2 at 10 d p.i. In RH 75% mortality of triatomines did not exceed 20%. Morphological studies and sequencing of the ITS and TEF region of Evlachovaea isolates showed that genus Evlachovaea must be synonymized with Isaria, and that the largest group of isolates previously identified as Evlachovaea are I. cateniannulata, whereas the smaller group is probably a new species of Isaria. The sequencing of the TEF and ITS regions showed that Metarhizium isolates belong to species M. anisopliae, M. robertsii, M. flavoviride var. pemphigi, and the largest group of Metarhizium isolates can be a new species of Metarhizium or a M. anisopliae variety. The results confirmed that in the Cerrado a high diversity of fungi is present and some of them, in special M. robertsii (IP 34) and Evlachovaea (IP 141) have potential for biological control of T. infestansItem Estudo das alterações morohistológicas em larvas de Aedes aegypti submetidas ao tanino catéquino isolado da Magonia pubescene (Sapindaceae) e ao diterpeno de Copaifera reticulata(Leguminosae)(Universidade Federal de Goiás, 2009-06-25) VALOTTO, Cleyde Ferreira Barreto; SILVA, Ionizete Garcia da; http://lattes.cnpq.br/5021551669347602The dengue and yellow fever are caused by Flavivirus, and are an importants problems in public health in the range of tropical and subtropical world. There is only available vaccine for yellow fever. The transmission of both diseases to humans is by the bite of female Aedes aegypti. The vector control is done through the elimination of breeding potential, application of larvicides in collections of water for adults vectors space applications of insecticides. The problems arising from continuous use of chemical insecticides have been the emergence of resistant populations to these products and concern about the environmental damage caused by slow degradation. In search of alternatives for the vector control, studies are being developed with substances of botanical origin, with the aim to control the vectors and preserve the environment. The use of natural insecticides has some advantages when compared to synthetic because they are renewable and have rapid degradation. Moreover, its composition is quite complex, reducing the speed of emergence of resistance and be of low toxicity to mammals, birds and environment. This study presents the morphohistologic and ultrastructural changes of catechist tannin extracted from Magonia pubescens, and the Diterpene extracted from Copaifera reticulata on the larvae of A. aegypti with the objective to evidence the mechanisms of action of these substances. For light microscopy, the 3rd stage larvae were subjected to a solution of catechist tannin 37ppm and the diterpene 9ppm, where they remained for up to 24h. Larvae that reached lethargic state were collected and fixed in 4% in the paraformoldehyde buffer 0.1 M sodium cacodilate pH 7.2, included in resin and the slides stained with hematoxylineosin technique. For electron microscopy, larvae were subjected to the same concentrations of catechist tannin and diterpene, where they remained for 22 h. Larvae that reached lethargic state were collected and dissected and their gut fixed in 2% glutaraldehyde, 2% paraformoldehyde, 3% sucrose in sodium buffer cacodilate 0.1 M pH 7.2 and post fixed in osmium tetroxide at 1% in cacodilate sodium 0.1 M. After this they were contrasted with uranyl acetate 1%, dehydrated, embedded and polymerized. The ultra sections were contrasted with uranyl acetate 3% and lead citrate and were caracterized by eletron microscopy. The changes caused by catechist tannin observed by light 20 and electron microscopy were high vacuolation, absence of cytoplasmic limits, cellular aging, cell disruption, vesicular apical formation with release of cytoplasmic content, increase in intercellular spaces, detachment of cells from the basal lamina and structural change of microvilli. Changes by diterpene by light and electron microscopy were high cytoplasmic vacuolation, cells and nuclei hypertrophy, degeneration of the edge brush, vesicular apical formation with release of cytoplasmic contents of cells, stratification of the epithelium and folds in the peritrophic matrix.