A trypsin inhibitor from seeds of faba bean (Vicia faba L.) was purified to near homogeneity as j... more A trypsin inhibitor from seeds of faba bean (Vicia faba L.) was purified to near homogeneity as judged by native-PAGE with about 11 % recovery using ammonium sulphate fractionation, ion-exchange chromatography on DEAE-cellulose and gel filtration through Sephadex G-100. The inhibitor had a molecular weight of 18 kD as determined by SDS-PAGE and Sephadex G-100. The inhibitor inhibited trypsin and
The fly Haematobia irritans irritans is one of the most important ectoparasites in cattle product... more The fly Haematobia irritans irritans is one of the most important ectoparasites in cattle production, due to its ability to suck large amounts of blood. This report describes the purification and characterization of a serine proteinase inhibitor (HiTI) present in H. i. irritans head and thorax extracts. The HiTI purified by affinity chromatography on trypsin–Sepharose has a molecular mass of
A utilização de Pichia pastoris para a produção de proteínas recombinantes apresenta inúmeras van... more A utilização de Pichia pastoris para a produção de proteínas recombinantes apresenta inúmeras vantagens que esse sistema agrega, destacando-se a exportação das moléculas para o meio extracelular. Isto permite que a obtenção das proteínas possa ser realizada por métodos de precipitação, com uso de sais neutros ou solventes orgânicos, sem trazer prejuízos. O objetivo deste trabalho foi avaliar a utilização de sulfato de amônio, acetona e metanol para obtenção da proteína recombinante Bm86 do carrapato Rhipicephalus microplus expressa por P. pastoris. A ação provocada pelos solventes orgânicos ocasionou uma solubilidade parcial das proteínas. Na quantificação por densitometria da proteína rBm86-CG, verificou-se que utilizando acetona (1:2) foi obtido 30,3 mg/L, metanol (1:2) 60,5 mg/L e com sulfato de amônio a 70% (83,5 mg/L). A manutenção das características antigênicas após a precipitação foi verificada pela técnica de Western Blot, sendo que a proteína rBm86-CG obtida pelos três mét...
The aim of this study was to evaluate tick fauna and identify the possible presence of Rickettsia... more The aim of this study was to evaluate tick fauna and identify the possible presence of Rickettsia spp. in ticks of the genus Amblyomma from two environmental preservation areas in different regions of Mato Grosso do Sul state, Brazil. CO2 traps, visual observation and cloth dragging were used to capture ticks. Three hundred ticks were submitted to the hemolymph test, and samples that showed organisms morphologically compatible with Rickettsia were used for rickettsial DNA detection by PCR. DNA was extracted using guanidine-phenol isothiocyanate, and the primers CS78 and CS323 were used for PCR, which amplified a 401-base pair fragment of the citrate synthase (gltA) gene. If positive, the DNA sample was tested by primers Rr190.70p and Rr190.602n that produce a 530 bp amplicon of the ompA gene that is present only in rickettsiae of the spotted fever group. A total of 1,745 adult ticks were collected, including 1,673 specimens of Amblyomma sculptum, 63 of Amblyomma coelebs, five of Amblyomma naponense and four of Amblyomma ovale. Thirteen ticks of the species A. ovale, A. coelebs and A. sculptum showed structures compatible with Rickettsia inside the hemocytes; after DNA extraction, the presence of Rickettsia spp. in a sample of A. ovale was confirmed by PCR in both analyzed fragments. In the sequencing analysis, 100% identity for the Rickettsia parkeri strain Atlantic rainforest was obtained according to GenBank. The two environmental preservation areas showed A. sculptum as the predominant species, as well as the presence of marked seasonality for this species. This paper is the first report of the R. parkeri strain Atlantic rainforest in A. ovale ticks in the state of Mato Grosso do Sul, Brazil.
Rondônia is the only state in the North Region of Brazil to have registered confirmed cases of Br... more Rondônia is the only state in the North Region of Brazil to have registered confirmed cases of Brazilian Spotted Fever (BSF). The present study investigated the epidemiological cycle of Rickettsia spp. by surveying free-living ixodofauna and tick parasitism of dogs in the municipality of Porto Velho, Rondônia State. Ticks and dogs were tested for the presence of Rickettsia spp. DNA and dog serum was tested for reactivity to anti-Rickettsia spp. antibodies. Tick collection and dog blood sampling were performed in peri-urban and rural environments at 11 locations. Eight free-living Amblyomma species and one Haemaphysalis species were collected: A. scalpturatum, A. naponense, A. oblongoguttatum, A. coelebs, A. latepunctatum, A. pacae, A. ovale, Amblyomma sp., and H. juxtakochi. Three tick species were found parasitizing dogs: Rhipicephalus sanguineus sensu lato, A. oblongoguttatum and A. ovale. Molecular analysis did not identify the presence of the gltA gene fragment in any tick specimen. Results from an indirect immunofluorescent assay (IFA) showed that 20.8% of peri-urban and 15.4% of rural dog sera exhibited reactivity to Rickettsia rhipicephali, Rickettsia amblyommatis, Rickettsia bellii and Rickettsia parkeri antigens. Antibody prevalence in dogs was 16.4%. This study is the first to describe the prevalence of Rickettsia spp. infection in dogs from Porto Velho municipality. Our findings enhance current knowledge of Rickettsia spp. circulation in the Western Amazon.
The objective of the study was to investigate the efficacy of cypermethrin, chlorpyrifos and pipe... more The objective of the study was to investigate the efficacy of cypermethrin, chlorpyrifos and piperonyl butoxide based pour-on and spray acaricides for the control of Rhipicephalus microplus in a naturally infested cattle herd. Fifty eight male Brangus cattle in the rearing phase were divided into treated (28) and untreated (30) groups. The treated group was subdivided in treated with a pour-on acaricide (13) and treated with a spray acaricide (15). Every 18 days, tick counts, acaricide treatment, weighing and clinical observation were performed on the animals, totaling four evaluation time points. The adult immersion tests were used for in vitro analysis of the study population to different chemical bases was assessed for primary results. Tick counts were separately compared between groups at each time point using the Kruskal-Wallis and Wilcoxon tests. Significantly fewer number of ticks were observed on the treated group compared to control group and also on the sprayed subgroup co...
A trypsin inhibitor from seeds of faba bean (Vicia faba L.) was purified to near homogeneity as j... more A trypsin inhibitor from seeds of faba bean (Vicia faba L.) was purified to near homogeneity as judged by native-PAGE with about 11 % recovery using ammonium sulphate fractionation, ion-exchange chromatography on DEAE-cellulose and gel filtration through Sephadex G-100. The inhibitor had a molecular weight of 18 kD as determined by SDS-PAGE and Sephadex G-100. The inhibitor inhibited trypsin and
The fly Haematobia irritans irritans is one of the most important ectoparasites in cattle product... more The fly Haematobia irritans irritans is one of the most important ectoparasites in cattle production, due to its ability to suck large amounts of blood. This report describes the purification and characterization of a serine proteinase inhibitor (HiTI) present in H. i. irritans head and thorax extracts. The HiTI purified by affinity chromatography on trypsin–Sepharose has a molecular mass of
A utilização de Pichia pastoris para a produção de proteínas recombinantes apresenta inúmeras van... more A utilização de Pichia pastoris para a produção de proteínas recombinantes apresenta inúmeras vantagens que esse sistema agrega, destacando-se a exportação das moléculas para o meio extracelular. Isto permite que a obtenção das proteínas possa ser realizada por métodos de precipitação, com uso de sais neutros ou solventes orgânicos, sem trazer prejuízos. O objetivo deste trabalho foi avaliar a utilização de sulfato de amônio, acetona e metanol para obtenção da proteína recombinante Bm86 do carrapato Rhipicephalus microplus expressa por P. pastoris. A ação provocada pelos solventes orgânicos ocasionou uma solubilidade parcial das proteínas. Na quantificação por densitometria da proteína rBm86-CG, verificou-se que utilizando acetona (1:2) foi obtido 30,3 mg/L, metanol (1:2) 60,5 mg/L e com sulfato de amônio a 70% (83,5 mg/L). A manutenção das características antigênicas após a precipitação foi verificada pela técnica de Western Blot, sendo que a proteína rBm86-CG obtida pelos três mét...
The aim of this study was to evaluate tick fauna and identify the possible presence of Rickettsia... more The aim of this study was to evaluate tick fauna and identify the possible presence of Rickettsia spp. in ticks of the genus Amblyomma from two environmental preservation areas in different regions of Mato Grosso do Sul state, Brazil. CO2 traps, visual observation and cloth dragging were used to capture ticks. Three hundred ticks were submitted to the hemolymph test, and samples that showed organisms morphologically compatible with Rickettsia were used for rickettsial DNA detection by PCR. DNA was extracted using guanidine-phenol isothiocyanate, and the primers CS78 and CS323 were used for PCR, which amplified a 401-base pair fragment of the citrate synthase (gltA) gene. If positive, the DNA sample was tested by primers Rr190.70p and Rr190.602n that produce a 530 bp amplicon of the ompA gene that is present only in rickettsiae of the spotted fever group. A total of 1,745 adult ticks were collected, including 1,673 specimens of Amblyomma sculptum, 63 of Amblyomma coelebs, five of Amblyomma naponense and four of Amblyomma ovale. Thirteen ticks of the species A. ovale, A. coelebs and A. sculptum showed structures compatible with Rickettsia inside the hemocytes; after DNA extraction, the presence of Rickettsia spp. in a sample of A. ovale was confirmed by PCR in both analyzed fragments. In the sequencing analysis, 100% identity for the Rickettsia parkeri strain Atlantic rainforest was obtained according to GenBank. The two environmental preservation areas showed A. sculptum as the predominant species, as well as the presence of marked seasonality for this species. This paper is the first report of the R. parkeri strain Atlantic rainforest in A. ovale ticks in the state of Mato Grosso do Sul, Brazil.
Rondônia is the only state in the North Region of Brazil to have registered confirmed cases of Br... more Rondônia is the only state in the North Region of Brazil to have registered confirmed cases of Brazilian Spotted Fever (BSF). The present study investigated the epidemiological cycle of Rickettsia spp. by surveying free-living ixodofauna and tick parasitism of dogs in the municipality of Porto Velho, Rondônia State. Ticks and dogs were tested for the presence of Rickettsia spp. DNA and dog serum was tested for reactivity to anti-Rickettsia spp. antibodies. Tick collection and dog blood sampling were performed in peri-urban and rural environments at 11 locations. Eight free-living Amblyomma species and one Haemaphysalis species were collected: A. scalpturatum, A. naponense, A. oblongoguttatum, A. coelebs, A. latepunctatum, A. pacae, A. ovale, Amblyomma sp., and H. juxtakochi. Three tick species were found parasitizing dogs: Rhipicephalus sanguineus sensu lato, A. oblongoguttatum and A. ovale. Molecular analysis did not identify the presence of the gltA gene fragment in any tick specimen. Results from an indirect immunofluorescent assay (IFA) showed that 20.8% of peri-urban and 15.4% of rural dog sera exhibited reactivity to Rickettsia rhipicephali, Rickettsia amblyommatis, Rickettsia bellii and Rickettsia parkeri antigens. Antibody prevalence in dogs was 16.4%. This study is the first to describe the prevalence of Rickettsia spp. infection in dogs from Porto Velho municipality. Our findings enhance current knowledge of Rickettsia spp. circulation in the Western Amazon.
The objective of the study was to investigate the efficacy of cypermethrin, chlorpyrifos and pipe... more The objective of the study was to investigate the efficacy of cypermethrin, chlorpyrifos and piperonyl butoxide based pour-on and spray acaricides for the control of Rhipicephalus microplus in a naturally infested cattle herd. Fifty eight male Brangus cattle in the rearing phase were divided into treated (28) and untreated (30) groups. The treated group was subdivided in treated with a pour-on acaricide (13) and treated with a spray acaricide (15). Every 18 days, tick counts, acaricide treatment, weighing and clinical observation were performed on the animals, totaling four evaluation time points. The adult immersion tests were used for in vitro analysis of the study population to different chemical bases was assessed for primary results. Tick counts were separately compared between groups at each time point using the Kruskal-Wallis and Wilcoxon tests. Significantly fewer number of ticks were observed on the treated group compared to control group and also on the sprayed subgroup co...
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Papers by Renato Andreotti E Silva