Veterinária
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11842
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Resultados da Pesquisa
Item Duddingtonia flagrans, Monacrosporium thaumasium and Pochonia chlamydosporia as possible biological control agents of Oxyuris equi and Austroxyuris finlaysoni(Journal of Helminthology, 2009-07-02) Braga, F.R.; Araújo, J.V.; Silva, A.R.; Araujo, J.M.; Carvalho, R.O.; Campos, A.K.; Tavela, A.O.; Ferreira, S.R.; Frassy, L.N.; Alves, C.D.F.The action of four fungal isolates of the species Duddingtonia flagrans (AC001), Monacrosporium thaumasium (NF34a) and Pochonia chlamydosporia (VC1 and VC4) on eggs of Oxyuris equi and Austroxyuris finlaysoni was evaluated in two assays (A and B). Eggs of O. equi (Test A) and A. finlaysoni (Test B) were plated on Petri dishes with 2% water-agar with grown fungal isolates and control without fungus. After 5, 10 and 15 days, 100 eggs were collected and classified according to the following parameters: type 1 effect, physiological and biochemical effect without morphological damage to the eggshell; type 2 effect, lytic effect with morphological alteration of the eggshell and embryo; and type 3 effect, lytic effect with morphological alteration of the eggshell and embryo, hyphal penetration and internal egg colonization. Pochonia chlamydosporia isolates VC1 and VC4 showed ovicidal activity for type 1, 2 and 3 effects on eggs of O. equi and eggs of A. finlaysoni. In vitro assays A and B showed that P. chlamydosporia had a negative influence on eggs of O. equi and A. finlaysoni and can be considered as a potential biological control agent of nematodes.Item Scanning electron microscopy of Ancylostoma spp. dog infective larvae captured and destroyed by the nematophagous fungus Duddingtonia flagrans(Micron, 2008-12-16) Maciel, A.S.; Araújo, J.V.; Campos, A.K.; Benjamin, L.A.; Freitas, L.G.The interaction between the nematode-trapping fungus Duddingtonia flagrans (isolate CG768) against Ancylostoma spp. dog infective larvae (L3) was evaluated by means of scanning electron microscopy. Adhesive network trap formation was observed 6 h after the beginning of the interaction, and the capture of Ancylostoma spp. L3 was observed 8 h after the inoculation these larvae on the cellulose membranes colonized by the fungus. Scanning electron micrographs were taken at 0, 12, 24, 36 and 48 h, where 0 is the time when Ancylostoma spp. L3 was first captured by the fungus. Details of the capture structure formed by the fungus were described. Nematophagous Fungus Helper Bacteria (NHB) were found at interactions points between the D. flagrans and Ancylostoma spp. L3. The cuticle penetration by the differentiated fungal hyphae with the exit of nematode internal contents was observed 36 h after the capture. Ancylostoma spp. L3 were completely destroyed after 48 h of interaction with the fungus. The scanning electron microscopy technique was efficient on the study of this interaction, showing that the nematode-trapping fungus D. flagrans (isolate CG768) is a potential exterminator of Ancylostoma spp. L3.Item Predatory activity of the fungi Duddingtonia flagrans, Monacrosporium thaumasium, Monacrosporium sinense and Arthrobotrys robusta on Angiostrongylus vasorum first-stage larvae(Journal of Helminthology, 2009-02-16) Braga, F.R.; Carvalho, R.O.; Araujo, J.M.; Silva, A.R.; Araújo, J.V.; Lima, W.S.; Ferreira, S.R.; Tavela, A.O.Angiostrongylus vasorum is a nematode that parasitizes domestic dogs and wild canids. We compared the predatory capacity of isolates from the predatory fungi Duddingtonia flagrans (AC001), Monacrosporium thaumasium (NF34), Monacrosporium sinense (SF53) and Arthrobotrys robusta (I31) on first-stage larvae (L 1 ) of A. vasorum under laboratory conditions. L 1 A. vasorum were plated on 2% water-agar (WA) Petri dishes marked into 4 mm diameter fields with the four grown isolates and a control without fungus. Plates of treated groups contained each 1000 L 1 A. vasorum and 1000 conidia of the fungal isolates AC001, NF34, SF53 and I31 on 2% WA. Plates of the control group (without fungus) contained only 1000 L 1 A. vasorum on 2% WA. Ten random fields (4 mm diameter) were examined per plate of treated and control groups, every 24 h for 7 days. Nematophagous fungi were not observed in the control group during the experiment. There was no variation in the predatory capacity among the tested fungal isolates (P . 0.05) during the 7 days of the experiment. There was a significant reduction (P , 0.05) of 80.3%, 74.5%, 74.2% and 71.8% in the means of A. vasorum L 1 recovered from treatments with isolates AC001, NF34, SF53 and I31, respectively, compared to the control without fungi. In this study, the four isolates of predatory fungi were efficient in the in vitro capture and destruction of A. vasorum L 1 , confirming previous work on the efficiency of nematophagous fungi in the control of nematode parasites of dogs and as a possible alternative method of biological control.