Navegando por Autor "Tavela, Alexandre de Oliveira"

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Atividade larvicida do extrato bruto enzimático do fungo Duddingtonia flagras sobre larvas de primeiro estádio de Angiostrongylus vasorum
(Revista da Sociedade Brasileira de Medicina Tropical, 2011-01-05) Braga, Fabio Ribeiro; Araujo, Juliana Milani; Tavela, Alexandre de Oliveira; Araújo, Jackson Victor de; Soares, Filippe Elias de Freitas; Geniêr, Hugo Leonardo André; Lima, Walter dos Santos; Mozzer, Lanuze Rose; Queiroz, José Humberto de
Angiostrongylus vasorum é um nematóide que parasita cães domésticos e eventualmente o homem. O objetivo deste trabalho foi observar a atividade predatória in vitro do extrato bruto enzimático do fungo Duddingtonia flagrans sobre larvas de primeiro estádio A. vasorum em condições laboratoriais no meio ágar-água 2%. Ao final do experimento, os percentuais de redução das L1 de A. vasorum observados foram de: 53,5% (24h) e 71,3% (48h) O extrato bruto enzimático do fungo D. flagrans destruiu in vitro as L1, podendo ser utilizado como controle biológico desse nematóide.
Avaliação da eficácia da associação in vitro e in vivo dos fungos nematófagos Duddingtonia flagrans, Monacrosporium thaumasium e Pochonia chlamydosporia sobre larvas infectantes de Ciatostomídeos e Trichostrongilídeos
(Universidade Federal de Viçosa, 2013-07-30) Tavela, Alexandre de Oliveira; Braga, Fábio Ribeiro; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4537780H4; Benjamin, Laércio dos Anjos; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4797917E7; Araújo, Jackson Victor de; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4780836D6; http://lattes.cnpq.br/0640807991403603; Silva, Ita de Oliveira e; http://lattes.cnpq.br/2393397917711039; Lima, Walter dos Santos; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783038T6; Carvalho, Rogério Oliva; http://lattes.cnpq.br/6226293652248977
O controle das verminoses de equinos e caprinos tem sido baseado na utilização de drogas antihelmínticas. No entanto, atualmente a resistência parasitária é um sério problema instalado em todo o mundo. Por outro lado, o controle biológico com fungos nematófagos tem sido estudado no combate alternativo de nematoides de animais domésticos, embora formulações contendo associações de dois ou mais gêneros diferentes de fungos ainda seja pouco explorada.O objetivo do presente trabalho foi avaliar a associação in vitro e in vivo dos fungos nematófagos Duddingtonia flagrans, Monacrosporium thaumasium e Pochonia chlamydosporia no controle das nematodioses de equinos e caprinos. O trabalho foi dividido em três ensaios experimentais denominados A, B e C, realizados em etapas distintas. No ensaio A foi testada a ação de três fungos nematófagos associados em condições laboratoriais utilizando placas de Petri contendo os fungos Duddingtonia flagrans (AC001), Monacrosporium thaumasium (NF34) e Pochonia chlamydosporia (VC1) no controle de ciatostomíneos parasitos de equinos. No ensaio B foi avaliada a associacão in vivo de péletes de alginato de sódio contendo os fungos D. flagrans e M. thaumasium no controle de ciatostomíneos. No ensaio C, foi avaliada a associação dos fungos D. flagrans e M. thaumasium sobre larvas infectantes de tricostrongilídeos em condições laboratoriais e após a passagem pelo tubo digestivo de caprinos. A utilização dos fungos D. flagans,M. thaumasium e P. chlamydosporia associados no controle de ciatostomíneose trichostrongilídeosin vitro e in vivo apresentou resultados promissores. Contudo, devem ser realizados mais testes a campo, com a finalidade de observar a eficiência da associação desses fungos no controle ambiental de nematóides de equinos e caprinos.
Biological control of cyathostomin (Nematoda: Cyathostominae) with nematophagous fungus Monacrosporium thaumasium in tropical southeastern Brazil
(Veterinary Parasitology, 2010-09-30) Tavela, Alexandre de Oliveira; Araújo, Jackson Victor; Braga, Fábio Ribeiro; Silva, André Ricardo; Carvalho, Rogério Oliva; Araujo, Juliana Milani; Ferreira, Sebastião Rodrigo; Carvalho, Giovanni Ribeiro
Horses are hosts to a wide variety of helminthes; the most important are the cyathostomin, or small strongyles. The viability of a fungal formulation (pellets) using the nematode- trapping fungus Monacrosporium thaumasium was assessed in biological control of horse cyathostomin. Two groups (fungus-treated and control) consisted of six mares in each group, crossbred (ages of 2.5 and 3.5 years), were placed in pastures of Cynodon sp. naturally infected with horse cyathostomin larvae. In the treated group, each animal received 1 g/10 kg body weight (0.2 g/10 kg live weight of fungus) of pellets of sodium alginate matrix containing the fungus M. thaumasium orally, twice a week for 6 months. In the control group, animals received (1 g/10 kg body weight) of pellets without fungus. The egg count per gram of feces showed difference (p < 0.01) in the animals treated with the fungus in relation to the control animals during all months of the experiment. The EPG percent- age decrease were 87.5%, 89.7%, 68.3%, 58.7%, 52.5% and 35.2% during June, July, August, September, October and November, respectively. In faecal cultures, there was difference (p < 0.05) among animals treated with fungus was found in relation to the control animals during all the experiment month, with percentage reduction of 67.5%, 61.4% and 31.8% in September, October and November, respectively. Difference (p < 0.01) was observed in the recovery of infective larvae from pastures that were collected up to 20 cm from the dung pats in pastures in the group treated with the fungus in relation to the control group with a reduction of 60.9% and between 0–20 and 0–40 cm from the faecal pat reduction (p < 0.01) was about 56% in the group treated with the fungus M. thaumasium in relation to the con- trol group pasture. There was no difference (p > 0.05) between the average weight gains in both animal groups. The treatment of horses with pellets containing the nematophagous fungus M. thaumasium can be effective in controlling cyathostomin in the tropical region of southeastern Brazil.
Coadministration of sodium alginate pellets containing the fungi Duddingtonia flagrans and Monacrosporium thaumasium on cyathostomin infective larvae after passing through the gastrointestinal tract of horses
(Research in Veterinary Science, 2012-11-22) Tavela, Alexandre de Oliveira; Araújo, Jackson Victor de; Braga, Fábio Ribeiro; Silveira, Wendeo Ferreira da; Silva, Vinicius Herold Dornelas e; Carretta Júnior, Moacir; Borges, Luana Alcântara; Araujo, Juliana Milani; Benjamin, Laércio dos Anjos; Carvalho, Giovanni Ribeiro; Paula, Alessandra Teixeira de
The predatory nematophagous fungi have been used as an alternative control of gastrointestinal nematodes of domestic animals in natural and laboratory conditions. However, it is unclear if the association of some of these species could bring some kind of advantage, from a biological standpoint. In this context, this study consisted of two tests in vitro: in assay A, the assessment of the viability of the association of pellets in sodium alginate matrix containing the fungus Duddingtonia flagrans (AC001) and Monacrosporium thaumasium (NF34) and its predatory activity on infective larvae (L3) of cyathostomin after passing through the gastrointestinal tract of horses and assay B, assessment of the cyathostomin L3 reduction percentage in coprocultures. Twelve crossbred horses, females, with a mean weight of 356 kg and previously dewormed were divided in three groups with four animals each: group 1, each animal received 50 g of pellets containing mycelial mass of the fungus D. flagrans and 50 g of pellets of the fungus M. thaumasium, associated and in a single oral dose; group 2, 100 g of pellets containing D. flagrans and 100 g of pellets containing M. thaumasium, associated and in a single oral dose; group 3, control. Faecal samples were collected from animals in the treated and control groups at time intervals of 12, 24, 36, 48, 60 and 72 h after the administration of treatments and placed in Petri dishes containing 2% water-agar (assay A) and cups for coprocultures (assay B). Subsequently, 1000 cyathostomin L3 were added to each Petri dish (assay A) and 1000 cyathostomin eggs were added to each coproculture (assay B) of fungi-treated and control groups. At the end of 15 days, there was observed that the two associations of pellets containing the fungi tested showed predatory activity after passing through the gastrointestinal tract of horses (assay A). In assay B, all the intervals studied showed reduction rate in the number of L3 recovered from coprocultures exceeding 80%. However, no difference (p > 0.01) was seen in recovery of not predated L3 between the fungi-treated groups in the time intervals studied. The results obtained showed that the associations of pellets (50 or 100 g of each fungal isolate) were viable after passage through the gastrointestinal tract in horses and could be used in natural conditions.
Controle biológico de ciatostomíneos de eqüinos resistentes a ivermectina e pamoato de pirantel com o fungo Monacrosporium thaumasium
(Universidade Federal de Viçosa, 2010-03-26) Tavela, Alexandre de Oliveira; Campos, Artur Kanadani; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4769590E3; Carvalho, Giovanni Ribeiro de; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4723068Z6; Araújo, Jackson Victor de; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4780836D6; http://lattes.cnpq.br/0640807991403603; Ribeiro Filho, José Dantas; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4701118J8; Nero, Luís Augusto; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4763792E2; Lima, Walter dos Santos; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783038T6; Guimarães, Marcos Pezzi; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783034Y8
A viabilidade de uma formulação do fungo predador de nematóides Monacrosporium thaumasium foi avaliada no controle biológico de ciatostomíneos de eqüinos. Dois grupos (tratado com o fungo e controle) constituídos por seis éguas em cada grupo, mestiças, com idade entre 2,5 a 3,5 anos, foram colocados em pastagens de Cynodon sp. naturalmente infectadas com larvas de ciatostomíneos de eqüinos. No grupo tratado, cada animal recebeu 1g/10 kg de peso corporal (0,2g/10kg de peso vivo de fungo) de péletes em matriz de alginato de sódio contendo o fungo M. thaumasium via oral, duas vezes por semana e durante seis meses. No grupo controle, os animais receberam 1g/10 kg de peso corporal de péletes sem o fungo. As contagens de ovos por grama de fezes demonstraram diferença (p<0,01) no grupo de animais tratados com o fungo em relação aos animais do grupo controle em todos os meses do experimento. Os percentuais de redução do OPG foram de 87,5%, 89,7%, 68,3%, 58,7%, 52,5% e 35,2% nos meses de junho, julho, agosto, setembro, outubro e novembro, respectivamente. Nas coproculturas foi encontrada diferença (p<0,05) entre os animais do grupo tratado com o fungo em relação aos animais do grupo controle em todos os meses do experimento, com percentuais de redução de 67,5%, 61,4% e 31,8% para setembro, outubro e novembro, respectivamente. Diferença (p<0,01) foi observada na recuperação de larvas infectantes das pastagens que foram coletadas até 20 cm de distância do bolo fecal no pasto do grupo tratado com o fungo em relação ao grupo controle com uma redução de 60,9% e, entre 20 e 40 cm do bolo fecal a redução (p<0,01) foi de 56% no pasto do grupo tratado com o fungo M. thaumasium em relação ao pasto do grupo controle. Não foi observada diferença (P>0,05) entre as médias de ganho de peso dos animais dos dois grupos. O tratamento de eqüinos com péletes contendo o fungo nematófago M. thaumasium, pode ser efetivo no controle de ciatostomíneos em região tropical do sudeste do Brasil.
Destruição de larvas infectantes de Strongyloides venezuelensis pelos fungos Duddingtonia flagrans, Arthrobotrys robusta e Monacrosporium sinense
(Revista da Sociedade Brasileira de Medicina Tropical, 2010-08-04) Braga, Fabio Ribeiro; Araujo, Juliana Milani; Silva, André Ricardo e; Araújo, Jackson Victor de; Carvalho, Rogério Oliva; Tavela, Alexandre de Oliveira; Silva, Manoel Eduardo da; Fernandes, Fernanda Mara; Melo, Alan Lane de
Strongyloides venezuelensis tem sido utilizado como um modelo para estudo da estrongiloidose humana. O objetivo deste trabalho foi comparar a capacidade predatória dos fungos nematófagos Duddingtonia flagrans (AC001), Arthrobotrys robusta (I-31) e Monacrosporium sinense (SF53) sobre larvas infectantes (L3) de Strongyloides venezuelensis em condições laboratoriais no meio ágar-água 2%. Ao final do experimento, os percentuais de redução de L3 de Strongyloides venezuelensis observados foram de: 93% (AC001); 77,2% (I-31) e 65,2% (SF53). Os fungos nematófagos foram capazes de capturar e destruir in vitro as L3, podendo ser utilizados como controladores biológicos de Strongyloides venezuelensis.
First report of the activity of predatory fungi on Angiostrongylus cantonensis (Nematoda: Angiostrongylidae) first-stage larvae
(Acta Tropica, 2013-04-26) Paula, Alessandra Teixeira de; Braga, Fabio Ribeiro; Carvalho, Lorendane Millena de; Lelis, Rosane Teixeira; Mello, Ingrid Ney Kramer de; Tavela, Alexandre de Oliveira; Soares, Fillipe Elias de Freitas; Maldonado, Arnaldo Junior; Garcia, Juberlan da Silva; Araújo, Jackson Victor de
The nematode Angiostrongylus cantonensis causes eosinophilic meningoencephalitis in humans and thus alternative methods of control should be studied. The objective of this work was to evaluate the predatory capacity of eight fungal isolates of the species Duddingtonia flagrans (AC001, CG768 and CG722), Monacrosporium thaumasium (NF34), M. sinense (SF53) and Arthrobotrys robusta (I31), A. cladodes (CG719) and A. conoides (I40) on first-stage larvae (L 1 ) of A. cantonensis under laboratory conditions. The treated groups contained 1000 conidia of the fungal isolates and 1000 A. cantonensis L 1 in Petri dishes containing 2% water-agar medium (2% WA). The control group (without fungi) contained only 1000 A. cantonensis L 1 in 2% WA. Evidence of predation was observed at the end of 7 days. Percentage reductions in L 1 were: AC001, 82.8%; CG768, 71.0%; CG722, 72.8%; NF34, 86.7%; SF53, 89.7%; I40, 48.3%; CG719, 84.7%; and I31, 80.4%. No significant difference was observed (p > 0.01) between the actions of the isolates used; however, a difference was noted (p < 0.01) in relation to the control group. The results of the present work, confirm previous reports of the effectiveness of the fungi D. flagrans, M. thaumasium, M. sinense and A. robusta in controlling larvae of potentially zoonotic nematodes, this being the first report on A. cantonensis L 1 .
Helminths of wild hybrid marmosets (Callithrix sp.) living in an environment with high human activity
(Revista Brasileira de Parasitologia Veterinária, 2013-07) Fuzessy, Lisieux Franco; Tavela, Alexandre de Oliveira; Silva, Vinicius Herold Dornelas e; Silva, Fernanda de Fátima Rodrigues da; Carretta Junior, Moacir; Silva, Ita de Oliveira; Souza, Vanner Boere
The objective of this study was to identify the helminth fauna in hybrid, non-native marmosets, through analysis of fecal samples. The study involved 51 marmosets (genus Callithrix) from five groups living in places with levels of human impact in Viçosa-MG. The marmosets were caught using a multiple-entrance trap and were anaesthetized. Feces were collected, refrigerated and analyzed by means of the sedimentation technique (Hoffmann-Pons-Janner). Eggs and parasites were identified, but not counted. Most of the marmosets (86%) were parasitized by at least one genus of helminths. Among the infected marmosets, 37% presented co-infection. The intestinal helminths comprised four different taxa: Primasubulura jacchi, Ancylostomatidae, Prosthenorchis sp. and Dilepididae.P. jacchi and Ancylostomatidae had higher prevalences (> 80% and > 40%, respectively) and were found in all marmoset groups. Dilepididae species were found in almost all the groups, but only accounted for around 30% of the marmosets. Prosthenorchis sp. showed a relatively low prevalence (< 10%) and was only found in one group. Although two parasites are commonly found in marmosets and other primates (P. jacchi and Prosthenorchis sp.), our study is the first record for Ancylostomatidae and Dilepididae. Factors like marmosets' feeding behavior and their contact with humans and other species of nonhuman primates seem to be determinants of infection among marmosets.
Hematology and blood biochemistry in wild hybrid marmosets from the Atlantic Forest, Brazil
(Ciência Rural, 2014-09) Silva, Ita de Oliveira e; Silva, Fernanda de Fátima Rodrigues da; Fuzessy, Lisieux Franco; Tavela, Alexandre de Oliveira; Carretta Júnior, Moacir; Silva, Vinícius Herold Dornelas e; Paula, Tarcízio Antônio Rego de; Boere, Vanner
This paper aims to describe the hematological and biochemical values of wild hybrid marmoset (Callithrix penicillata and C. geoffroyi) found in a forest zone of Southeastern Brazil. The marmosets were anaesthetized using ketamine and xylazine hydrochloride. Blood samples (0.5-1mL) were collected through the venipuncture of the femoral vein. Hematological and biochemical analyses were performed using automated counters and biochemical kits. The comparison for sex (adult males vs. adult females) and age class (juvenile vs. adult) physiological data and weight were analyzed through Student's t-test for independent samples. Significant differences between sex were observed in erythrocytes (P<0.01) and hemoglobin (P<0.05). The present study provides essential baseline information on the normal blood values of wild hybrid marmosets, the data of which are not readily accessible from the existing body of scientific literature on nonhuman primates.
In vitro predatory activity of conidia of fungal isolates of the Duddingtonia flagrans on Angiostrongylus vasorum first-stage larvae
(Revista da Sociedade Brasileira de Medicina Tropical, 2011-09-30) Braga, Fabio Ribeiro; Araujo, Juliana Milani; Araújo, Jackson Victor de; Soares, Filippe Elias de Freitas; Tavela, Alexandre de Oliveira; Frassy, Luiza Neme; Lima, Walter dos Santos; Mozzer, Lanuze Rose
Angiostrongylus vasorum is a nematode that parasitizes molluscs, dogs, and even man. The objective was to evaluate the predatory activity of the conidia of two fungal isolates of Duddingtonia flagrans (AC001 and CG722) on first-stage larvae (L1) of A. vasorum in laboratory conditions. At the end of the experiment, there were significant reductions (p<0.01) of 74.5% and 63.2%, on average, in the A. vasorum L1 recovered in the AC001 and CG722 treatment conditions, respectively. The two isolates of fungi were efficient in the capture and destruction of A. vasorum L1.
Influence of the preservation period in silica-gel on the predatory activity of the isolates of Duddingtonia flagrans on infective larvae of cyathostomins (Nematoda: Cyathostominae)
(Experimental Parasitology, 2011-05-24) Braga, Fabio Ribeiro; Araújo, Jackson Victor; Araujo, Juliana Milani; Tavela, Alexandre de Oliveira; Ferreira, Sebastião Rodrigo; Soares, Filippe E. Freitas; Benjamin, Laércio dos Anjos; Frassy, Luiza Neme
The continued maintenance of nematophagous fungi predatory activity under laboratory conditions is one of the basic requirements for a successful biological control. The purpose of this study was to evaluate the influence of time on the preservation of the fungus Duddingtonia flagrans (AC001 and CG722) stored in silica-gel for 7 years and their subsequent predatory activity on cyathostomin L3 larvae in 2% water-agar medium (2% WA). Samples of the isolates AC001 and CG722, originating from vials containing grains of silica-gel sterilized and stored for 7 years, were used. After obtaining fungal conidia, the predation test was conducted over 7 days on the surface of 9.0 cm Petri dishes filled with 2% WA. In the treated groups each Petri dish contained 500 cyathostomin L3 and conidia of fungal isolates in 2% WA. In the control group (without fungi) the plates contained 500 L3 in 2% WA. The experimental results showed that isolated AC001 and CG722 were efficient in preying on cyathostomin L3 (p < 0.01) compared to control (without fungus). However, no difference was observed (p > 0.01) in the predatory activity of the fungal isolates tested. Comparing the groups, there was a significant reductions of cyathostomin L3 (p < 0.01) of 88.6% and 78.4% on average recovered from the groups treated with the isolates AC001 and CG722, respectively, after 7 days. The results of this test showed that the fungus D. flagrans (AC001 and CG722) stored in silica-gel for at least 7 years maintained its predatory activity on cyathostomin L3.
Nematophagous fungi combinations reduce free-living stages of sheep gastrointestinal nematodes in the field
(Journal of Invertebrate Pathology, 2017-08-25) Silveira, Wendeo Ferreira da; Braga, Fabio Ribeiro; Tavela, Alexandre de Oliveira; Santos, Lucas Fernando dos; Domingues, Rafael Reis; Aguiar, Anderson Rocha; Ferraz, Carolina Magri; Carvalho, Lorendane Millena de; Ayupe, Thiago de Hollanda; Zanuncio, Jose Cola; Araújo, Jackson Victor de
Gastrointestinal nematodes (GIN) can reduce or limit sheep production. Currently there is a clear deficiency in the action of drugs for the control of these parasites. Nematophagous fungi are natural enemies of GIN. Fungal combinations have potential for reducing GIN populations. The aim of this study was to evaluate the efficiency combinations of nematophagous fungi in sodium alginate matrix pellets for the biological control agents of gastrointestinal sheep nematode parasites in the field. The nematophagous fungi (0.2 mg of fungus per kg of body weight), Arthrobotrys conoides, A. robusta, Duddingtonia flagrans, and Monacrosporium thaumasium were used. The treated groups were administered mycelium combinations in the following combinations: group 1 (D. flagrans + A. robusta); group 2 (M. thaumasium + A. conoides). The control group did not receive any fungal pellets. We used three groups with eight Santa Inês sheep each. Each animal was treated with approximately 1 g of pellet per 10 kg of live weight. During the experimental period, we evaluated: number of eggs per gram of feces (EPG), infective larvae (L3) per kg of dry matter, larvae recovered from coprocultures, packed cell volume, total plasma protein concentration of sheep, and environmental conditions. Group 2 EPG (M. thaumasium + A. conoides) differed from the control group in September and October. The number of L3/kg of dry matter recovered from animals of groups 1 and 2 at distances of 0–20 and 20–40 cm from the fecal pats was lower than the control group. The packed cell volume and total plasma proteins of treated animals were similar to those of the control group. The combination of treatment groups (D. flagrans + A. robusta and M. thaumasium + A. conoides) reduced the number of L3/kg of pasture. Therefore, treatment of nematophagous fungal combinations have the potential to manage free-living stages of GIN in sheep.