Veterinária
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11842
Navegar
10 resultados
Resultados da Pesquisa
Item Efficacy of Monacrosporium thaumasium in the control of goat gastrointestinal helminthiasis in a semi-arid region of Brazil(Parasitology Research, 2013-02) Braga, Fabio Ribeiro; Araújo, Jackson Victor de; Vilela, Vinícius Longo Ribeiro; Feitosa, Thais Ferreira; Lucena, Samuel Cavalcante de; Dantas, Elaine Silva; Athayde, Ana Célia Rodrigues; Silva, Wilson WouflanThe aim of the present study was to test a pellet formulation of Monacrosporium thaumasium in a sodium alginate matrix in the biological control of goat gastrointestinal helminthiasis in a semi-arid region of northeastern Brazil. An area of 2.4 ha was divided into three paddocks, with seven goats kept on each paddock, during the months of March to August 2011: group 1 received 3 g/10 kg live weight of M. thaumasium pellets (NF34a) twice a week; group 2 was given 0.2 mg/kg of 0.2 % moxidectin orally every 30 days; and group 3 received 3 g/10 kg live weight of pellets without fungus twice per week. Each month, two tracer goats was placed in each group for 30 days and then killed and necropsied. The M. thaumasium group showed a 34 % reduction in eggs per gram, higher packed cell volume rates and a lower parasitic load in the tracers compared with the other groups. The 0.2 % moxidectin group had weight gain of 5.7 kg; the M. thaumasium group, 3.6 kg; and the control group had an average reduction in weight of 1.1 kg. The use of M. thaumasium pellets may be effective as an alternative method to control goat gastrointestinal helminthiasis in the semi-arid region of northeastern Brazil.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 Viability and nematophagous activity of the freeze-dried fungus Arthrobotrys robusta against Ancylostoma spp. infective larvae in dogs(Veterinary Parasitology, 2010-10-20) Carvalho, Rogério Oliva; Braga, Fabio Ribeiro; Araújo, Jackson VictorViability and in vitro and in vivo activities of freeze-dried conidia of the predatory fungus Arthrobotrys robusta (I-31) were evaluated against infective larvae (L3) of Ancylostoma spp. in dogs. A. robusta conidia were lyophilized and stored at 4 °C for a month. Freeze-dried conidia were diluted to 1 × 103 conidia/ml and tested in vivo. The treated group consisted of a solution containing conidia (1 ml) and 1000 Ancylostoma spp. (L3) placed on Petri dishes plated with 2% water–agar (2% WA), at 25 °C, in the dark for 10 days. The control group consisted of 1000 Ancylostoma spp. L3, plated on 2% WA. After 10 days, Ancylostoma spp. L3 from both the treated and the control groups were recovered and counted. The in vivo test was performed on two dogs by administering a single oral dose of freeze-dried conidia (1.5 × 105) in aqueous solution to one animal and only water to the other. Fecal samples were collected at 12, 24 and 48 h after the treatments, plated 2% WA plates and incubated at 25 °C for 15 days. A thousand Ancylostoma spp. L3 larvae were spread on these plates. At day 15, infective L3 recovered from the treated and control groups were counted. In the in vitro test, A. robusta was able to survive the freeze-drying process, grow in the plates, form traps and capture Ancylostoma spp. L3. There was a 75.38% decrease in the number of infective larvae recovered from the treated group. The in vivo test showed that freeze-dried A. robusta conidia survived the passage through the gastrointestinal tract of the treated dog, was able to grow in the plates and capture Ancylostoma spp. L3, reducing the number of recovered L3 (p < 0.01). Freeze-drying can be an alternative method for conservation of conidia of nematophagous fungi.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 Pochonia chlamydosporia in the biological control of Fasciola hepatica in cattle in Southeastern Brazil(Parasitology Research, 2013-03-14) Dias, A. S.; Araújo, J. V.; Braga, F. R.; Puppin, A. C.; Perboni, W. R.Biological control with the use of nematophagous fungi has been described very successfully by many authors and presents itself as a complementary control method, acting on the free-living forms of helminths. The efficacy of a formulation containing the fungus Pochonia chlamydosporia in controlling Fasciola hepatica eggs in faeces was evaluated in an experimental field assay. Two bovine groups (six animals each) were used: A (control) and B (treated with fungus). At 30 days after deworming, the animals were separated into two similar paddocks with flooded areas and were given pellets containing 25 % mycelial mass (group B) or no fungus (group A) at a dose of 1 g/10 kg body weight, twice a week, during 18 months. Faecal samples were harvested fortnightly in the animals of groups A and B and they were submitted at examination of quantitative sedimentation. The mean count of F. hepatica eggs per grams of faeces was significantly higher in group A (1.19) compared with those from group B (0.82) (P < 0.01). After 18 months, animals from group B had gained 42.33 kg above (17.82 % more by weight) (P < 0.01), compared with the control group (A). Every month, faecal samples from paddocks A and B were collected and they were incubated. P. chlamydosporia was identified only in sample source of the paddock B. It can be concluded that the application of this fungical formulation with P. chlamydosporia 25 % mycelial mass was effective in reducing the availability of eggs in the environment and reinfections in calves in natural conditions.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 Optimizing protease production from an isolate of the nematophagous fungus Duddingtonia flagrans using response surface methodology and its larvicidal activity on horse cyathostomins(Journal of Helminthology, 2010-04-04) Braga, F.R.; Araújo, J.V.; Soares, F.E.F.; Araujo, J.M.; Genier, H.L.A.; Silva, A.R.; Carvalho, R.O.; Queiroz, J.H.; Ferreira, S.R.Protease production from Duddingtonia flagrans (isolate AC001) was optimized and the larvicidal activity of the enzymatic extract was evaluated on infective horse cyathostomin larvae (L3). Duddingtonia flagrans was grown in liquid medium with eight different variables: glucose, casein, bibasic potassium phosphate (K 2 HPO 4 ), magnesium sulphate (MgSO 4 ), zinc sulphate (ZnSO 4 ), ferrous sulphate (FeSO 4 ), copper sulphate (CuSO 4 ) and temperature. The Plackett– Burman analysis showed a significant influence of MgSO 4 , CuSO 4 and casein (P , 0.05) on protease production by D. flagrans in liquid medium. Central composite design indicated that the highest proteolytic activity was 39.56 U/ml as a function of the concentrations of casein (18.409 g/l), MgSO 4 (0.10 g/l) and CuSO 4 (0.50 mg/l). A significant difference (P , 0.01) was found for the larval number between the treated and control groups at the end of the experiment. A reduction of 95.46% in the number of free-living larvae was found in the treated group compared with the control. The results of this study suggest that protease production by D. flagrans (AC001) in liquid medium was optimized by MgSO 4 , CuSO 4 and casein, showing that the optimized enzymatic extract exerted larvicidal activity on cyathostomins and therefore may contribute to large-scale industrial production.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.Item Biological control of Taenia saginata eggs(Parasitological Institute of SAS, Košice, 2010-10-09) Araújo, J.; Braga, F.; Araújo, J.; Soares, F.; Geniêr, H.Taenia saginata, is a cestode with zoonotic potentially. The objective of this work was to evaluate the ovicide activity (type 3 effect) of the fungus, Paecilomyces lilacinus (PL1), on the eggs of Taenia saginata, in vitro. The eggs were inverted in Petri dishes containing PL1, or in Petri dishes without the fungus (control). After 5, 10, or 15 days, we extracted approximately 100 eggs for evaluation and for classifying the ovicide activity. At the end of the 15 days of interaction, a significant difference (p < 0.05) due to the ovicide activity of PL1, was noted in relation to the control group, with a medium percentage (type 3 effect) at 24.6 %. These results show that the fungus, P.lilacinus (PL1), destroyed the eggs of T. saginata, suggesting its biological control potential of the eggs of this cestode.