Artigos
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11852
Navegar
8 resultados
Resultados da Pesquisa
Item Application of a formulation of the nematophagous fungus Duddingtonia flagrans in the control of cattle gastrointestinal nematodiosis(World Journal of Microbiology and Biotechnology, 2007-09) Dias, Anderson S.; Araújo, Jackson V.; Campos, Artur K.; Braga, Fabio R.; Fonseca, Thiago A.The viability of a formulation of Duddingtonia flagrans was assessed in the control of parasite gastrointestinal nematodes of cattle. Two groups (A and B) of eight crossbred Holstein × Zebu cattle, approximately one year old, were placed in Brachiaria decumbens pasture. Each animal in group B (treated) received orally 20 g sodium alginate pellets containing mycelial mass of the D. flagrans fungus, while the animals in the group A (control) received pellets without fungus for seven months, starting in March 2005. The egg per gram of feces counting the gastrointestinal nematodes showed a difference (P < 0.05) in the treated group in June, July and August, with reductions of 58% (June), 47% (July) and 51% (August) compared to the control group. The infective larvae recovered in the pastures collected up to 20 cm from distance of the fecal dung in group B differed (P < 0.01) from the larvae recovered in group A. At the end of the experimental period, the animals in group B presented a greater weight gain (P < 0.01) compared to the untreated group (A). The treatment of cattle with pellets containing the D. flagrans nematophagous fungus, at the dose and duration used was effective in controlling the infective larvae of gastrointestinal nematodes of cattle.Item In vitro activity of a serine protease from Monacrosporium thaumasium fungus against first-stage larvae of Angiostrongylus vasorum(Parasitology Research, 2012-01-10) Braga, Fabio R.; Araújo, Jackson V.; Soares, Filippe E. F.; Lima, Walter dos Santos; Mozer, Lanuze R.; Queiróz, José H.A serine protease from the nematophagous fungus Monacrosporium thaumasium (NF34a) was purified, partially characterized and tested in vitro in control of the first larval stage of Angiostrongylus vasorum. NF34a grew in liquid culture medium, producing its crude extract that was purified by ion exchange chromatography. The fractions with high protease activity were collected in a pool, and elution of proteases was monitored by enzymatic assay and protein content. Purification steps were monitored by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Protease activity was determined under different pH and temperature conditions, and the inhibitor effects of metal ions and phenylmethylsulfonyl fluoride (PMSF) were assessed. In an experimental test, the infection process of NF34a on first-stage larvae of A. vasorum was investigated. A purified serine protease (Mt1) was identified, with an approximate molecular mass of 40 kDa and apparent homogeneity in SDS-PAGE, having optimal activity at pH 7.0 to 8.0 and temperature of 60°C. Mg2+ and Zn2+ partially inhibited the activity of Mt1 while PMSF inhibited it completely. Mt1 production was observed when NF34a was grown using first-stage larvae of A. vasorum as the only source of carbon and nitrogen. These results show that the enzyme may have a possible role in the infection process of the larvae. In the in vitro test of applicability against A. vasorum L1, we observed a reduction in the number of larvae of 23.9% (p < 0.05) in the group treated with Mt1 compared with the control group. However, even this low reduction demonstrates that the Mt1 is important in the infection process.Item Destruction of Anoplocephala perfoliata eggs by the nematophagous fungus Pochonia chlamydosporia(Journal of Equine Veterinary Science, 2010-12) Silva, André R.; Araújo, Jackson V.; Braga, Fábio R.; Alves, Camila D. F.; Ribeiro Filho, José DantasThe in vitro effect of an isolate of the nematophagous fungus Pochonia chlamydosporia (VC1) on the eggs of Anoplocephala perfoliata was evaluated. The eggs were morphologically analyzed for their integrity using light microscopy (10× objectives), plated on 9.0-cm diameter petri dishes containing 2% WA culture medium with and without fungal isolate (control), grown for 10 days, and 10 replicates were prepared per group. In all, 1000 eggs of A perfoliata were plated on petri dishes containing 2% water agar culture medium with (VC1) and without the fungal isolate (control). After 3, 5, 7, and 10 days, approximately 100 eggs were removed from each plate and classified on the basis of the following parameters: without alteration; type 1, lytic effect without morphological damage to eggshell; type 2, lytic effect with morphological alteration of embryo and eggshell; and type 3, lytic effect with morphological alteration of embryo and eggshell, in addition to hyphal penetration and internal egg colonization and destruction. The P chlamydosporia fungus demonstrated ovicidal activity (P < .05) on the eggs of A perfoliata in the studied intervals presenting type 3 effects of 35%, 42.5%, 53.83%, and 71.17% for the intervals 3, 5, 7, and 10 days, respectively. P chlamydosporia is a potential biological control agent for the eggs of A perfoliata.Item Biological control of sheep gastrointestinal nematodiasis in a tropical region of the southeast of Brazil with the nematode predatory fungi Duddingtonia flagrans and Monacrosporium thaumasium(Parasitology Research, 2009-09-16) Silva, Andre R.; Araújo, Jackson V.; Braga, Fabio R.; Frassy, Luiza N.; Tavela, Alexandre O.; Carvalho, Rogerio O.; Castejon, Fernanda V.Formulations in matrix of sodium alginate (pellets) of the nematode predatory fungi Duddingtonia flagrans and Monacrosporium thaumasium were evaluated in the biolog- ical control of sheep gastrointestinal nematodiasis. Three groups (1, 2, and 3), each one with eight sheep of the Santa Inês breed, at the ages of 15–48 months, were placed in paddocks of Brachiaria decumbens for 5 months. In group 1, each animal received 1 g/10 kg of live weight (l.w.) of pellets of D. flagrans (0.2 g of fungus/10 kg l.w.). In group 2, each animal received 1 g/10 kg of l.w. of pellets of the fungus M. thaumasium (0.2 g of fungus/10 kg l.w.), twice a week, for 5 months. In group 3 (control), the animals received 1 g/10 kg of live weight of pellets without fungus. The monthly averages of the egg countings per gram of feces of the animals of groups 1 and 2 treated were 71.6% and 61.1% smaller, respectively, in comparison to the animals of group 3 (control). The treatment of sheep with pellets containing the nematophagous fungi D. flagrans and M. thaumasium may be used as an alternative for the control of sheep gastrointestinal nematodiasis.Item In vitro predatory activity of nematophagous fungi and after passing through gastrointestinal tract of equine on infective larvae of Strongyloides westeri(Parasitology Research, 2010-04-06) Araujo, Juliana M.; Araújo, Jackson V.; Braga, Fabio R.; Carvalho, Rogério O.Three isolates of predator fungi Duddingtonia flagrans (AC001), Monacrosporium thaumasium (NF34), and Arthrobotrys robusta (I-31) were assessed in in vitro test regarding the capacity of prey infective larvae (L3) Strongyloides westeri. Compared to control, without fungus, there was a significant decrease (P < 0.01) of 80.4%, 67.9%, and 72.8% in means of infective larvae S. westeri recovered from treatments with isolates AC001, NF34, and I-31, respectively. All tested isolates were efficient in the capture of S. westeri (P > 0.01) in vitro test. Linear regression coefficients of treated and control groups were −0.21 for control, −0.32 for D. flagrans, −0.34 for M. thaumasium, and −0.22 for A. robusta. In the following, isolates AC001 and NF34 were assessed in vivo regarding the capacity of supporting the passage through equine gastrointestinal tract without loss of ability of preying infective larvae S. westeri. Fungal isolates survived the passage and were efficient in preying L3 since the first 12 h of collection (P < 0.01) in relation to the control group (without fungus). Compared to control, there was a significant decrease (P < 0.01) of 76.4% and 76.7% (12 h), 86.4% and 85.9% (24 h), 88.3% and 87.7% (48 h), and 89.9% and 87.2% (72 h) in means of infective larvae S. westeri recovered from treatments with isolates AC001 and NF34, respectively. Linear regression coefficients of L3 of recovered S. westeri regarding the collections due to time were 1.93 for control, −3.52 for AC001, and −2.64 for NF34. Fungi D. flagrans and M. thaumasium (NF34) have demonstrated to be promising for use in the biological control of equine parasite S. westeri.Item Biological control of Fasciola hepatica eggs with the Pochonia chlamydosporia fungus after passing through the cattle gastrointestinal tract(Parasitology Research, 2011-07-20) Dias, Anderson S.; Araújo, Jackson V.; Braga, Fábio R.; Araujo, Juliana M.; Puppin, André C.; Fernandes, Fernanda M.; Ramos, Rafael F.; Bertonceli, Raul M.; Silva, Renata G. da; Perboni, Wilber R.Fasciolosis is a disease caused by Fasciola hepatica responsible for causing significant losses in livestock. This study aimed to evaluate the Pochonia chlamydosporia fungus (isolate VC1) on F. hepatica eggs after passing through the cattle gastrointestinal tract. For this evaluation, 1 g pellet was given in sodium alginate matrix per kilogram live weight containing 25% of fungal mycelium from isolate VC1 per animal. Twelve animals were used, six treated and six untreated (control). Some stool samples were collected from the groups of treated and control animals, at the times of 12, 18, 24, 48, 72, and 96 h after the pellets' administration. Then, from each stool sample of treated and control groups, 2 g was placed in a Petri dish of 9 cm in diameter, containing 2% water–agar and 1,000 eggs of F. hepatica. It was observed that the fungus was effective in preying upon the eggs in the samples recovered at all of the schedules starting at 12 h. Furthermore, differences were observed (p < 0.01) in the destruction of eggs in the Petri dishes in the treated group compared with the control group. The ovicidal effect was observed after 7 days of interaction. The ovicidal P. chlamydosporia fungus was effective in destroying F. hepatica eggs; therefore, it is suggested that this fungus could be employed as agent for the control of helminth eggs.Item Predatory capability of the nematophagous fungus Arthrobotrys robusta preserved in silica gel on infecting larvae of Haemonchus contortus(Tropical Animal Health and Production, 2014-02-08) Braga, Fabio R.; Carvalho, Rogério O.; Silva, André R.; Araújo, Jackson V.; Frassy, Luiza N.; Lafisca, Andrea; Soares, Filippe E. F.Biological control of gastrointestinal nematodiasis in ruminants is an alternative to reduce the number of infective larvae. The fungal isolates predatory activity preservation is a basic requirement for the success of this control type. The aim of this work is to evaluate the predatory capacity of the fungus Arthrobotrys robusta (isolate I-31), preserved on silica gel on infective larvae of Haemonchus contortus under laboratory conditions on 2 % water agar (2 % WA). In this essay, A. robusta storage on silica gel showed successful predatory activity on H. contortus L3 larvae (p < 0.01) compared to the control group. Nematophagous fungi were not observed in the control group during the experiment. There was a significant reduction (p < 0.01) of 73.84 % in the means of H. contortus (L3) recovered from treatment with isolate I-31 compared to the control without fungi. Results indicate that A. robusta (I-31) could survive stored on silica gel for at least 7 years and keep its predatory activity on H. contortus (L3).Item Survival of Pochonia chlamydosporia in the gastrointestinal tract of experimentally treated dogs(Research in Veterinary Science, 2011-10-20) Araujo, Juliana M.; Araújo, Jackson V.; Braga, Fabio R.; Araújo, Dayane M.; Ferreira, Sebastião R.; Soares, Filippe E.F.; Benjamin, Laércio dos A.The predatory capacity of the nematophagous fungus Pochonia chlamydosporia (isolate VC4) after passage through the gastrointestinal tract of dogs was assessed in vivo against Toxocara canis eggs. Twelve dogs previously wormed were divided into two groups of six animals and caged. The treatments consisted of a fungus-treated group (VC4) and a control group without fungus. Each dog of the fungus-treated group received a single 4 g dose of mycelial mass of P. chlamydosporia (VC4). Fecal samples from animals of both groups (treated and control) were collected at five different times (6, 12, 24, 36, and 48 h) after fungal administration, and placed in Petri dishes. Each Petri dish of both groups for each studied time interval received approximately 1000 T. canis eggs. Thirty days after the fecal samples were collected, approximately one hundred eggs were removed from each Petri dish of each studied time interval and evaluated by light microscopy (LM) and scanning electron microscopy (SEM). Microscopy examination of plates inoculated with the fungus showed that the isolate VC4 was able to destroy the T. canis eggs with destruction percentages of 28.6% (6 h), 29.1% (12 h), 32.0% (24 h), 31.7% (36 h), and 37.2% (48 h). These results suggest that P. chlamydosporia can be used as a tool for the biological control of T. canis eggs in feces of contaminated dogs.