18 results on '"Santi, Lucélia"'
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2. Relação patógeno-hospedeiro : análise bioquímica e proteômica da interação do fungo Metarhizium anisopliae e seus hospedeiros artrópodes
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Santi, Lucélia, Vainstein, Marilene Henning, and Schrank, Augusto
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Metarhizium anisopliae - Abstract
O fungo filamentoso Metarhizium anisopliae é um patógeno capaz de infectar uma grande variedade de artrópodes. A identificação de proteínas e atividades enzimáticas que participem ativamente do processo de infecção é um importante alvo de estudo. Com o objetivo de identificar tais proteínas, uma nova estratégia foi utilizada: imunoproteômica. Estudos relacionados à produção de esporos, formulação e infectividade de M. anisopliae para o controle de Dysdercus peruvianus (Hemiptera: Pyrrhocoridae) foram também realizados. Formulações contendo 10% de óleo de soja adicionado a 108 conídio.mL-¹ foi a mais efetiva para ninfas e adultos, sendo as ninfas mais sensíveis ao fungo. Analisando as proteínas extraídas da superfície do esporo, foram identificadas atividades relacionadas à proteção, nutrição e patogenicidade do fungo, como proteases, quitinases, lipases, fosfolipase C (identificada pela primeira vez em esporos), trealase e enzimas envolvidas na proteção contra espécies reativas de oxigênio. Utilizando a metodologia de imunoproteômica diferencial, foram observadas diferenças na secreção de proteínas de M. anisopliae em relação aos dois hospedeiros testados: D. peruvianus e Rhipicephalus microplus (Acari: Ixodidae). Foram identificadas proteases, quitinases e proteínas relacionadas com o processo de infecção em outros organismos (DNase e proteína rica em prolina). Os resultados obtidos neste trabalho indicam que M. anisopliae é eficiente no controle de ninfas e adultos de D. peruvianus, e formulações contendo 10% de óleo de soja são as mais eficientes dentre as testadas. Um extenso arsenal enzimático foi detectado no sobrenadante de esporos lavados, favorecendo a adaptação do fungo a diferentes substratos, hospedeiros, condições ambientais e nichos de atuação, seja como patógeno ou saprófito. Os resultados de imunoproteômica reforçam a potencialidade do fungo em secretar diferentes proteínas para adaptar-se, no caso, à infecção de D. peruvianus ou R. microplus, além de evidenciar proteínas e atividades compartilhadas entre os diferentes hospedeiros. As proteínas e enzimas identificadas neste trabalho poderão, isoladamente, ser alvo de novas pesquisas a fim de elucidar o processo de infecção de M. anisopliae, em especial à fase inicial da patogênese. The filamentous fungus Metarhizium anisopliae is a pathogen that infects a variety of arthropods. The identification of proteins and enzymatic activities that participate actively in the infection process is an important target of study. In order to identify these proteins, a new strategy was used: immunoproteomics. Studies related to the spore production, formulation and M. anisopliae infectivity for the control of Dysdercus peruvianus (Hemiptera: Pyrrhocoridae) were also made. Formulations containing 10% of soybean oil added to 108 conidia.mL-¹ was the most effective for nymphs and adults, and the nymphs were more susceptible to fungus. Analyzing the proteins extracted from the spore surface, the activities were identified related to the protection, nutrition and pathogenicity of the fungus, such as proteases, chitinases, lipases, phospholipase C (first identified in spores), trealase and enzymes involved in protection to reactive oxygen species. Using the differential immunoproteomics, differences were observed in the M. anisopliae secretion proteins in the two hosts tested: D. peruvianus and Rhipicephalus microplus (Acari: Ixodidae). Proteases, chitinases and proteins related to the infection process of other organisms (DNase and proline-rich protein) were identified. The results in this work indicate that M. anisopliae is effective for the control of D. peruvianus nymphs and adults, and that formulations containing 10% of soybean oil were the most efficient between tested. An extensive arsenal was detected in supernatant of washed spores, favoring the adaptation of the fungus to different substrates, host, environmental conditions and niches of action, either as pathogen or saprophyte. The results of immunoproteomics reinforce the capability of the fungus to secrete different proteins to adapt, in this case, the infection of D. peruvianus or R. microplus, in addition to evidence proteins and activities shared between different hosts. The proteins identified in this work and enzymes may, alone, be the subject of further research to elucidate the infection process of M. anisopliae, particularly in the early stages of pathogenesis.
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- 2009
3. The entomopathogen Metarhizium anisopliae can modulate the secretion of lipolytic enzymes in response to different substrates including components of arthropod cuticle
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Beys da silva, Walter O., Santi, Lucélia, Corrêa, Ana Paula F., Silva, Lucas A.D., Bresciani, Fernanda R., Schrank, Augusto, and Vainstein, Marilene H.
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METARHIZIUM anisopliae , *ARTHROPODA , *BIOLOGICAL pest control , *ENZYMES , *PATHOGENIC microorganisms - Abstract
Abstract: The filamentous fungus Metarhizium anisopliae is a well-characterized, arthropod pathogen used in the biological control of arthropod pests. Studies on the regulation of enzymes related to host infection such as proteases and chitinases have been reported but little is known about regulation of lipolytic enzymes in this fungus. Here we present the effects of different carbon sources such as components of the arthropod cuticle on the secretion of lipolytic enzymes by M. anisopliae. Differences in the induction of lipolytic activity were observed between the several carbon sources tested. Higher activities of lipase or lipase/esterase were found in culture media containing the arthropod integument components chitin and cholesteryl stearate. Several bands of lipolytic activity were also detected in zymograms, thus suggesting an important set of lipolytic enzymes secreted by the fungus. These results show that the fungus can modulate the secretion of lipolytic activity in response to host integument components, thus reinforcing the potential role of these enzymes during M. anisopliae infection. [Copyright &y& Elsevier]
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- 2010
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4. Metarhizium anisopliae host–pathogen interaction: differential immunoproteomics reveals proteins involved in the infection process of arthropods
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Santi, Lucélia, Silva, Walter O.B., Pinto, Antônio F.M., Schrank, Augusto, and Vainstein, Marilene H.
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METARHIZIUM anisopliae , *HOST-fungus relationships , *ARTHROPOD populations , *ENTOMOPATHOGENIC fungi , *PHYSIOLOGICAL control systems , *HYDROLASES , *PROTEOLYTIC enzymes , *FUNGAL proteins - Abstract
Abstract: Metarhizium anisopliae is an entomopathogenic fungus well characterized for the biocontrol of a wide range of plagues. Its pathogenicity depends on the secretion of hydrolytic enzymes that degrade the host cuticle. To identify proteins involved in the infection process and in host specify, immunoproteomic analysis was performed using antiserum produced against crude extract of M. anisopliae cultured in the presence of Rhipicephalus (Boophilus) microplus and Dysdercus peruvianus cuticles. Spots detected using antisera produced against M. anisopliae cultured in cuticles and spore surface proteins, but not with antiserum against M. anisopliae cultured in glucose, were identified so as to give insights about the infection process. An MS/MS allowed the identification of proteases, like elastase, trypsin, chymotrypsin, carboxypeptidase and subtilisin (Pr1A, Pr1I and PR1J), chitinases, DNase I and proline-rich protein. Chymotrypsin and Pr1I were inferred as host specific, being recognized in D. peruvianus infection only. This research represents an important contribution to the understanding the adaptation mechanisms of M. anisopliae to different hosts. [Copyright &y& Elsevier]
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- 2010
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5. Conidial surface proteins of Metarhizium anisopliae: Source of activities related with toxic effects, host penetration and pathogenesis
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Santi, Lucélia, Beys da Silva, Walter O., Berger, Markus, Guimarães, Jorge A., Schrank, Augusto, and Vainstein, Marilene H.
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METARHIZIUM anisopliae , *FUNGI imperfecti , *PROTEINS , *TOXINS , *CHITINASE , *MYCOSES , *PROTEOLYTIC enzymes , *LIPASES , *ARTHROPODA - Abstract
Abstract: Conidial contact with an arthropod surface is the first step of the fungal penetration and infection process. However, conidia of Metarhizium anisopliae have associated components, like enzymes that could be involved in triggering the penetration process and toxic effects that have not yet been well characterized. Fungi produce many enzymes that also are toxic components found in bacteria and animal venoms and thus may be considered as potential virulence factors. In this work, we report several enzymatic activities from spore surface protein extracts. The major proteolytic activities observed in spore surface proteins (SSP) were Pr1 and Pr2 activities, in that order. According to the zymograms obtained, SSP contain different proteases. SSP contain trehalase, exo- and endo-chitinase activities, and seven different chitinase bands which have been observed in zymograms. Activities involved in protection against reactive oxygen species (ROS) were also detected. Two lipolytic enzymes were also detected in lipase zymograms. Phospholipase C activity, closely related to microbial pathogenesis, was detected for the first time in M. anisopliae conidia. These activities described could be an initial step towards understanding the mechanisms involved in the first stage of M. anisopliae infection process and its toxic effects against arthropod hosts. [Copyright &y& Elsevier]
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- 2010
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6. Metarhizium anisopliae lipolytic activity plays a pivotal role in Rhipicephalus (Boophilus) microplus infection
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Beys da Silva, Walter O., Santi, Lucélia, Schrank, Augusto, and Vainstein, Marilene H.
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METARHIZIUM anisopliae , *LIPOLYSIS , *RHIPICEPHALUS , *LIPASE inhibitors , *PHYSIOLOGICAL control systems , *MICROFUNGI - Abstract
Abstract: Lipases secreted by Metarhizium anisopliae, an important biological control agent, could potentially be involved in the host infection process. Here, we present the activity profile during the host infection process and the effect of lipase activity inhibitor ebelactone B on infection. The previous treatment of spores with lipase activity inhibitor, ebelactone B, completely inhibited lipolytic activity and prevented the infection of the Rhipicephalus (Boophilus) microplus host. The results herein presented prove, for the first time, the importance of lipase activity in M. anisopliae host infection process. The filamentous fungus Metarhizium anisopliae is one of the most important and studied biological agents for the control of several arthropod pests, including the cattle tick Rhipicephalus (Boophilus) microplus. Lipases secreted by M. anisopliae could potentially be involved in the host infection process. This work presents the activity profile during the host infection process and the effect of lipase activity inhibitor ebelactone B on infection. During the course of tick exposure to spores (6–120h) lipase activity increased from 0.03±0.00U to 0.312±0.068U using ρNP palmitate as substrate. In zymograms, bands of lipase activity were detected in ticks treated with spores without inhibitor. The previous treatment of spores with lipase activity inhibitor, ebelactone B, completely inhibited lipolytic activity, at all times specified, and prevented the infection of the R. microplus host. Spores treated with the inhibitor did not germinate on the tick, although this effect was not observed in the culture medium. The results herein presented prove, for the first time, the importance of lipase activity in M. anisopliae host infection process. [Copyright &y& Elsevier]
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- 2010
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7. Differential immunoproteomics enables identification of Metarhizium anisopliae proteins related to Rhipicephalus microplus infection
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Santi, Lucélia, Silva, Walter Orlando Beys da, Pinto, Antônio Frederico Michel, Schrank, Augusto, and Vainstein, Marilene Henning
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IMMUNOLOGY , *PROTEOMICS , *METARHIZIUM anisopliae , *RHIPICEPHALUS , *CUTICLE , *PROTEOLYTIC enzymes , *PATHOGENIC microorganisms - Abstract
Abstract: Differential immunoproteomics was applied to identify proteins secreted by Metarhizium anisopliae induced by the Rhipicephalus microplus cuticle. In addition, IgG anti-spore surface proteins were used for searching for proteins possibly involved in early stages of fungus versus tick infection. LC-MS/MS of differentially secreted proteins led to the identification of proteases (carboxypeptidase and Pr1A), chitinase, carboxylic acid transport and proline-rich protein. Differential immunoproteomics strategy facilitated the detection and the identification of new proteins related to M. anisopliae host–pathogen interaction and could be used in further works to identify novel proteins related to other microbial infection systems. [Copyright &y& Elsevier]
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- 2009
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8. Characterization of a spore surface lipase from the biocontrol agent Metarhizium anisopliae
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Silva, Walter O.B., Santi, Lucélia, Berger, Markus, Pinto, Antonio F.M., Guimarães, Jorge A., Schrank, Augusto, and Vainstein, Marilene H.
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FUNGAL enzymes , *LIPASES , *FUNGAL spores , *SURFACE analysis , *METARHIZIUM anisopliae , *PHYSIOLOGICAL control systems , *ION exchange chromatography , *HYDROPHOBIC surfaces , *INTERFACES (Physical sciences) - Abstract
Abstract: A Metarhizium anisopliae spore surface lipase (MASSL) strongly bound to the fungal spore surface has been purified by ion exchange chromatography on DEAE sepharose followed by ultrafiltration and hydrophobic interaction chromatography on phenyl sepharose. Electrophoretic analyses showed that the molecular weight of this lipase is ∼66kDa and pI is 5.6. Protein sequencing revealed that identified peptides in MASSL shared identity with several lipases or lipase-related sequences. The enzyme was able to hydrolyze triolein, the animal lipid cholesteryl stearate and all ρNP ester substrates tested with some preference for esters with a short acyl chain. The values of K m and V max for the substrates ρNP palmitate and ρNP laurate were respectively 0.474mM and 1.093mMolmin−1 mg−1 and 0.712mM and 5.696mMolmin−1 mg−1. The optimum temperature of the purified lipase was 30°C and the enzyme was most stable within the most acid pH range (pH 3–6). Triton X-100 increased and SDS reduced enzyme lipolytic activity. MASSL activity was stimulated by Ca2+, Mg2+ and Co2+ and inhibited by Mn2+. The inhibitory effect on activity exerted by EDTA and EGTA was limited, while the lipase inhibitor Ebelactone B completely inhibited MASSL activity as well as PMSF. Methanol 0.5% apparently did not affect MASSL activity while β-mercaptoethanol activated the enzyme. [Copyright &y& Elsevier]
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- 2009
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9. Cuticle-induced endo/exoacting chitinase CHIT30 from Metarhizium anisopliae is encoded by an ortholog of the chi3 gene
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da Silva, Márcia Vanusa, Santi, Lucélia, Staats, Charley Christian, da Costa, Andrea Miura, Colodel, Edson Moleta, Driemeier, David, Vainstein, Marilene Henning, and Schrank, Augusto
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METARHIZIUM anisopliae , *ENTOMOPATHOGENIC fungi , *ENZYMES , *ETHYLENE glycol , *GENETICS - Abstract
Abstract: The characterization of chitinase genes and enzymes is an important step toward global understanding of the chitinolytic system in entomopathogenic fungi. Chitinase CHIT30 from Metarhizium anisopliae var. anisopliae (strain E6) has both endo- and exochitinase activities and is a potential determinant of pathogenicity. Serum anti-CHIT30 specifically detected this chitinase amongst five isoenzymes shown in glycol-chitin activity gels. Chitinase CHIT30 secretion is upregulated by chitin, tick cuticle and low concentrations of N-acetylglucosamine (0.25%) and is downregulated by both high N-acetylglucosamine (1%) and glucose (1%) concentrations. Chitinase CHIT30 was produced at tick cuticle during fungal infection. The chi3 gene was assigned to code chitinase CHIT30 in M. anisopliae var. anisopliae. [Copyright &y& Elsevier]
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- 2005
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10. Expression and characterization of the 42 kDa chitinase of the biocontrol fungus Metarhizium anisopliae in Escherichia coli.
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Baratto, César Milton, Da Silva, Marcia Vanusa, Santi, Lucélia, Passaglia, Luciane, Schrank, Irene Silveira, Vainstein, Marilene Henning, and Schrank, Augusto
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METARHIZIUM anisopliae ,METARHIZIUM ,FUNGI ,ENZYMES ,CHITIN ,GENES - Abstract
Copyright of Canadian Journal of Microbiology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2003
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11. Characterization of Mycoviruses and Analyses of Chitinase Secretion in the Biocontrol Fungus Metarhizium anisopliae.
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Paz Giménez-Pecci, Maria de la, Bogo, Maurício R., Santi, Lucélia, de Moraes, Caroline Kriger, Cláudia Tatiana Corrêa, Vainstein, Marilene Henning, and Schrank, Augusto
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METARHIZIUM anisopliae ,METARHIZIUM ,FUNGAL viruses ,ELECTRON microscopy ,FUNGI ,RNA - Abstract
Metarhizium anisopliae is the best-characterized entomopathogen and is used to control insect pests in sugar cane plantations in Brazil on a commercial scale. We have previously reported the infection of some M. anisopliae strains by dsRNA mycoviruses. Here we describe the purification and characterization of the viruses (MaV-A1, MaV-M5, MaV-RJ) in terms of dsRNA content, capsid proteins, electron microscopy, Western blot, and hybridization patterns. One spontaneous mutant lost some of the high molecular weight dsRNA components and showed significant alterations in colony morphology and spore production, suggesting that viral genes interfere with fungal phenotype. A comparison between dsRNA mycovirus-free and infected M. anisopliae isolates showed that virus-free isolates have increased endochitinase secretion. By comparing the following parameters: the buoyant density in CsCl of the presumed virions; the number and estimated molecular weight of the dsRNA components and the molecular mass of the capsid proteins to other mycoviruses previously described, we suggest the inclusion of MaV-A1 and MaV-M5 in the family Totiviridae and MaV-RJ in the family Partitiviridae. [ABSTRACT FROM AUTHOR]
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- 2002
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12. Susceptibility of Loxosceles sp. to the arthropod pathogenic fungus Metarhizium anisopliae: potential biocontrol of the brown spider.
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Beys-da-Silva, Walter O., Santi, Lucélia, Berger, Markus, Guimarães, Jorge A., Schrank, Augusto, and Vainstein, Marilene H.
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LOXOSCELES ,METARHIZIUM anisopliae ,ARTHROPOD pests ,PHYSIOLOGICAL control systems ,PUBLIC health - Abstract
Background Loxosceles genus (brown spider) is an important pest with great impact on public health. Thus, more effective strategies for spider control are necessary. Methods Three isolates of Metarhizium anisopliae fungus were tested for the control of Loxosceles sp. Results Metarhizium anisopliae isolate E6 was highly virulent to the Loxosceles sp. spider, causing 100% mortality at 109 conidia/ml after 12 days and 9 days for juvenile and adult spiders, respectively. Conclusions This is the first report of the pathogenicity of M. anisopliae against a venomous arthropod. This fungus could offer an interesting alternative to reduce loxoscelism in future biocontrol strategies. [ABSTRACT FROM PUBLISHER]
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- 2013
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13. Metarhizium anisopliae E6 secretome reveals molecular players in host specificity and toxicity linked to cattle tick infection.
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Saciloto-de-Oliveira, Laura Rascovetzki, Broetto, Leonardo, Alves, Camila Innocente, da Rosa, Rafael Lopes, Calegari Alves, Yohana Porto, da Silva, Rodrigo Campos, Berger, Markus, Macedo, Alexandre José, Dalberto, Pedro Ferrari, Bizarro, Cristiano Valim, Guimarães, Jorge Almeida, Yates, John R., Santi, Lucélia, and Beys-da-Silva, Walter Orlando
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CATTLE tick , *METARHIZIUM anisopliae , *ENTOMOPATHOGENIC fungi , *BEAUVERIA bassiana , *PROTEOMICS , *PROTEIN expression , *GREATER wax moth , *BIOLOGICAL pest control agents , *ACARICIDES - Abstract
Although Metarhizium anisopliae is one of the most studied fungal biocontrol agents, its infection mechanism is far from being completely understood. Using multidimensional protein identification technology (MudPIT), we evaluated the differential secretome of M. anisopliae E6 induced by the host Rhipicephalus microplus cuticle. The proteomic result showed changes in the expression of 194 proteins after exposure to host cuticle, such as proteins involved in adhesion, penetration, stress and fungal defense. Further, we performed a comparative genomic distribution of differentially expressed proteins of the M. anisopliae secretome against another arthropod pathogen, using the Beauveria bassiana ARSEF2860 protein repertory. Among 47 analyzed protein families, thirty were overexpressed in the M. anisopliae E6 predicted genome compared to B. bassiana. An in vivo toxicity assay using a Galleria mellonella model confirmed that the M. anisopliae E6 secretome was more toxic in cattle tick infections compared to other secretomes, including B. bassiana with cattle ticks and M. anisopliae E6 with the insect Dysdereus peruvianus , which our proteomic results had also suggested. These results help explain molecular aspects associated with host infection specificity due to genetic differences and gene expression control at the protein level in arthropod-pathogenic fungi. [ABSTRACT FROM AUTHOR]
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- 2023
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14. Integrated control of an acaricide-resistant strain of the cattle tick Rhipicephalus microplus by applying Metarhizium anisopliae associated with cypermethrin and chlorpyriphos under field conditions.
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Webster, Anelise, Reck, José, Santi, Lucélia, Souza, Ugo A., Dall’Agnol, Bruno, Klafke, Guilherme M., Beys-da-Silva, Walter O., Martins, João Ricardo, and Schrank, Augusto
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ACARICIDE resistance , *CATTLE diseases , *RHIPICEPHALUS , *METARHIZIUM anisopliae , *CYPERMETHRIN , *TICKS as carriers of disease - Abstract
The efficacy of the fungus Metarhizium anisopliae to control ticks has been shown in several in vitro experiments. However, few studies have been undertaken in field conditions in order to demonstrate the applicability of its use as a biological control of ticks and its combination with chemical acaricides. The aim of the present study was to evaluate the efficacy of M. anisopliae to control an acaricide-resistant strain of Rhipicephalus microplus under laboratory and field conditions. First, the compatibility of M. anisopliae strain (TIS-BR03) with commercial acaricides and its potential to control the cattle tick were evaluated in vitro . In general, acaricide treatments had mild effects on fungus viability. In the field experiment, the median of treatment efficacy with acaricide only, M. anisopliae only and combination of M. anisopliae with acaricide were 71.1%, 56.3% and 97.9%, respectively. There is no statistical difference between groups treated with M. anisopliae and acaricide alone. Thus, in this work we have demonstrated the applicability of M. anisopliae use associated or not with chemical acaricides on field conditions in order to control an acaricide-resistant strain of the cattle tick R. microplus . [ABSTRACT FROM AUTHOR]
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- 2015
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15. Enzymatic activities and effects of mycovirus infection on the virulence of Metarhizium anisopliae in Rhipicephalus microplus.
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Perinotto, Wendell M.S., Golo, Patricia S., Coutinho Rodrigues, Caio J.B., Sá, Fillipe A., Santi, Lucélia, Beys da Silva, Walter O., Junges, Angela, Vainstein, Marilene H., Schrank, Augusto, Salles, Cristiane M.C., and Bittencourt, Vânia R.E.P.
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FUNGAL viruses , *PATHOGENIC fungi , *FUNGAL virulence , *PROTEOLYTIC enzymes , *METARHIZIUM anisopliae , *RHIPICEPHALUS - Abstract
Abstract: The present study aimed to evaluate the pathogenic potential of different Metarhizium anisopliae s.l. isolates and to determine whether differences in enzymatic activities of proteases, lipases and chitinases and infection with mycoviruses affect the control of Rhipicephalus microplus achieved by these fungal isolates. Engorged female ticks were exposed to fungal suspensions. The lipolytic and proteolytic activities in the isolates were evaluated using chromogenic substrates and the chitinolytic activity was determined using fluorescent substrates. A gel zymography was performed to determine the approximate size of serine proteases released by M. anisopliae isolates. To detect mycoviral infections, dsRNA was digested using both RNAse A and S1 endonuclease; samples were analyzed on an agarose gel. Four of the five isolates tested were infected with mycovirus; however, the level of control of R. microplus ticks achieved with the only isolate free of infection (isolate CG 347) was low. This finding suggests that mycoviral infection does not affect the virulence of fungi against ticks. Although all five isolates were considered pathogenic to R. microplus, the best tick control and the highest levels of enzymatic activity were achieved with the isolates CG 629 and CG 148. The in vitro activities of lipases, proteases and chitinases produced by M. anisopliae s.l. differed among isolates and may be related to their virulence. [Copyright &y& Elsevier]
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- 2014
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16. Exposure to a sublethal menadione concentration modifies the mycelial secretome and conidial enzyme activities of Metarhizium anisopliae sensu lato and increases its virulence against Rhipicephalus microplus.
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Coutinho-Rodrigues, Caio Junior Balduino, Rosa, Rafael Lopes da, Freitas, Maria Clemente de, Fiorotti, Jéssica, Berger, Markus, Santi, Lucélia, Beys-da-Silva, Walter Orlando, Yates III, John R., and Bittencourt, Vânia Rita Elias Pinheiro
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METARHIZIUM anisopliae , *MENADIONE , *RHIPICEPHALUS , *ENZYMES , *CELL communication , *FUNGAL enzymes , *DIGESTIVE enzymes , *RICKETTSIAL diseases - Abstract
• M. anisopliae s.l. isolate was low tolerant to menadione (MND). • Half of MND LC 50 was used as a sublethal dose in the experiments. • Changes in the colony and conidial enzymatic activities were noticed. • Better efficacy against R. microplus with fungal LC 50 and LT 50 reductions. • Mycelial secretome reveals a specific increase in some Pr1 isoforms. Menadione (MND) is known to induce oxidative stress in fungal cells. Here, we explore how exposure to this molecule alters conidial enzyme activities, fungal efficacy against Rhipicephalus microplus, and mycelial secretion (secretome) of an isolate of Metarhizium anisopliae sensu lato. First, the fungus was exposed to different MND concentrations in potato-dextrose-agar (PDA) to determine the LC 50 by evaluating conidia germination (38μM). To ensure high cell integrity, a sublethal dose of MND (half of LC 50) was added to solid (PDA MND) and liquid media (MS MND). Changes in colony growth, a slight reduction in conidia production, decreases in conidial surface Pr1 and Pr2 activities as well as improvements in proteolytic and antioxidant (catalase, superoxide dismutase, and peroxidase) conidial intracellular activities were observed for PDA MND conidia. Additionally, PDA MND conidia had the best results for killing tick larvae, with the highest mortality rates until 15 days after treatment, which reduces both LC 50 and LT 50 , particularly at 108 conidia mL−1. The diversity of secreted proteins after growth in liquid medium + R. microplus cuticle (supplemented or not with half of MND LC 50), was evaluated by mass spectrometry-based proteomics. A total of 654 proteins were identified, 31 of which were differentially regulated (up or down) and mainly related to antioxidant activity (catalase), pathogenicity (Pr1B, Pr1D, and Pr1K), cell repair, and morphogenesis. In the exclusively MS MND profile, 48 proteins, mostly associated with cellular signaling, nutrition, and antioxidant functions, were distinguished. Finally, enzymatic assays were performed to validate some of these proteins. Overall, supplementation with MND in the solid medium made conidia more efficient at controlling R. microplus larvae, especially by increasing, inside the conidia, the activity of some infection-related enzymes. In the liquid medium (a consolidated study model that mimics some infection conditions), proteins were up- and/or exclusively-regulated in the presence of MND, which opens a spectrum of new targets for further study to improve biological control of ticks using Metarhizium species. [ABSTRACT FROM AUTHOR]
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- 2021
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17. Updating the application of Metarhizium anisopliae to control cattle tick Rhipicephalus microplus (Acari: Ixodidae).
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Beys-da-Silva, Walter O., Rosa, Rafael L., Berger, Markus, Coutinho-Rodrigues, Caio J.B., Vainstein, Marilene H., Schrank, Augusto, Bittencourt, Vânia R.E. P., and Santi, Lucélia
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RHIPICEPHALUS , *METARHIZIUM anisopliae , *CATTLE tick , *IXODIDAE , *MITES , *ENTOMOPATHOGENIC fungi , *PLANT products - Abstract
The bovine tick, Rhipicephalus microplus , is the main ectoparasite of cattle and causes loss of billions of dollars worldwide in lost meat, milk, and leather production, as well as control expenses. In addition to systemically impacting the host during the parasitic act, this parasite is also an important disease vector. Traditionally, the main commercial control of the tick is achieved through application of chemical acaricides, which can leave residues in the meat and milk. Moreover, ticks can become resistant to these chemicals due to their massive and incorrect use. Many alternative methods have been tested including vaccines and natural products from plant origin. However, the efficacy of these treatments is variable and limited, especially when used alone. Arthropod-pathogenic fungi, such as Metarhizium anisopliae , are among the natural microbial agents with promising potential to be used alone or in association with other products, for example with chemical acaricides. This article discusses several aspects of bovine tick control related to the use of M. anisopliae , which is one of the most studied and viable alternative tools for effective tick control. Image 1 • Dozens of tested M. anisopliae isolates able to control the cattle tick. • Field and pen studies proved the biocontrol potential. • Alternative to chemical acaricides and to control multi-resistant tick strains. • Combined use with commercial chemical acaricides. • Tick control on pasture suitable for organic production. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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18. Secretoma do fungo biocontrolador Metarhizium anisopliae relacionado à infecção do carrapato bovino Rhipicephalus microplus
- Author
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Scherer, Karine, Sperotto, Raul Antonio, Santi, Lucélia, and Silva, Walter Orlando Beys da
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Proteômica ,Rhipicephalus microplus ,Metarhizium anisopliae ,Controle biológico ,CB - Abstract
Submitted by FERNANDA DA SILVA VON PORSTER (fdsvporster@univates.br) on 2016-09-22T18:55:12Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2016KarineScherer.pdf: 501039 bytes, checksum: ba846d16b9e36cfee8ac3c7682596d48 (MD5) Approved for entry into archive by Ana Paula Lisboa Monteiro (monteiro@univates.br) on 2016-09-29T19:18:09Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2016KarineScherer.pdf: 501039 bytes, checksum: ba846d16b9e36cfee8ac3c7682596d48 (MD5) Made available in DSpace on 2016-09-29T19:18:09Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2016KarineScherer.pdf: 501039 bytes, checksum: ba846d16b9e36cfee8ac3c7682596d48 (MD5) Previous issue date: 2016-09 Prosup/CAPES O controle biológico é considerado uma alternativa natural e ecológica para o controle de pragas, evitando os problemas causados pela utilização de agentes químicos. Na comparação entre as duas alternativas, o controle biológico apresenta inúmeras vantagens, principalmente quanto ao impacto ambiental, custo, manuseio, especificidade e não desenvolvimento de resistência. No entanto, os biopesticidas necessitam, na maioria das vezes, de mais tempo para efetivar o controle das pragas-alvo, quando comparado ao controle químico. Entre os microrganismos utilizados no controle biológico de pragas, o fungo Metarhizium anisopliae está entre os mais estudados e aplicados para diversas pragas, inclusive para o controle do carrapato bovino Rhipicephalus microplus, um ectoparasita hematófago responsável por grandes prejuízos econômicos no Brasil e no mundo. O estudo do processo de infecção do hospedeiro pode contribuir muito na otimização do processo de biocontrole visando a redução do tempo de morte da praga a ser controlada. Neste trabalho, utilizando shotgun proteomics e um sistema de cultura in vitro indutor do sistema de infecção, identificamos mais de 400 proteínas. Destas, 133 foram exclusivas da condição de infecção e 56 diferencialmente reguladas quando comparadas ao controle. Nestes resultados, foram identificadas proteínas responsáveis pela degradação e penetração da cutícula, além de moduladores da resposta do hospedeiro e proteção do fungo. Muitas das proteínas foram identificadas pela primeira vez neste sistema e 12 aparentemente são compartilhadas na infecção de M. anisopliae em insetos, portanto, não estando relacionadas à especificidade ao hospedeiro. Este perfil de proteínas secretadas, identificadas neste trabalho, representa uma contribuição para o entendimento da interação patógeno-hospedeiro e futuramente podem contribuir na otimização do controle biológico e na seleção de isolados mais eficientes especificamente para o carrapato bovino R. microplus. The biological control is considered a natural and ecologic alternative to control pests avoiding the issues related to the use of chemical compounds. The biocontrol presents several benefits as the lower environmental impact, cost, handling, specificity, and the non-development of resistant pest strains. However, normally biopesticides need more time to kill and control pests when compared to chemical control. Among microorganisms used in biological control the fungus Metarhizium anisopliae is one of the most studied and applied to control several pests, including the cattle tick Rhipicephalus microplus. The understanding of the host infection process may contribute to optimize the biocontrol through the reduction of the time to kill the target pest. In this work, applying shotgun proteomics and an in vitro culture strategy to induce the infection system in R. microplus we identified more than 400 proteins. Among these proteins, 133 were exclusively identified in the infection condition and 56 were differentially regulated when compared to control. Several of these proteins are related to host-cuticle digestion and penetration, fungal defense and modulators of host immune system. Besides, many of these proteins are being reported for the first time linked to M. anisopliae infection and 12 are shared in infection of insects and probably not connected to host specificity. The secreted protein profile identified here represents a contribution to the understanding of host-pathogen interaction and may help to optimize the biocontrol and to select fungal isolates more specific and effiicent to control the cattle tick R. microplus.
- Published
- 2016
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