Revista Brasileira De Parasitologia Veterinaria, 2008
A study on the population behavior of Amblyomma cajennense and Amblyomma dubitatum larvae, nymphs... more A study on the population behavior of Amblyomma cajennense and Amblyomma dubitatum larvae, nymphs andadult free-living stages was carried out in Coronel Pach...
Trabalho realizado pelo Departamento de Nutrição Clínica e Social da UFOP em parceria com a UFMG,... more Trabalho realizado pelo Departamento de Nutrição Clínica e Social da UFOP em parceria com a UFMG, com recursos das instituições: UFOP e UFMG. Baseado em dissertação: "Anemia ferropriva e seus fatores predisponentes, em escolares da área rural
, to compare the anti-parasitic efficacy and productivity effects of 2 subcutaneous injections of... more , to compare the anti-parasitic efficacy and productivity effects of 2 subcutaneous injections of doramectin (200 mcg/kg) administered 56 days apart with that of a single injection of ivermectin (630 mcg/kg) in growing cattle. Ninety-six crossbred male cattle were randomly allocated to 3 groups of 32 animals, based on bodyweight. All animals grazed the same pasture during the study. Treatments consisted of either 2 injections of doramectin (days 0 and 56), one injection of ivermectin (day 0), or no treatment (controls). Cattle weight, nematode egg counts, coprocultures, tick counts, tropical warble nodule counts, and presence of screw worms were determined on days 0, 28, 56, 84, 112 and 140. Mean fecal egg counts from cattle in both medicated groups were significantly reduced compared to those of controls. Coprocultures showed a predominance of Cooperia spp. and Haemonchus spp. On days 84 and 112, fecal egg counts of doramectin-treated cattle were significantly (p<0.05) lower than those for ivermectin-treated cattle. Tick counts were also reduced in the doramectin-and ivermectin-treatment groups compared to those for controls. On day 84, ticks counts of doramectin-treated cattle were significantly lower than those of ivermectin-treated cattle. At the end of the 140-day study, doramectin-treated cattle had a mean weight gain of 11.3 kg and 14.1 kg higher than that of ivermectin-treated cattle (p<0.05) and controls (p<0.05), respectively. It is concluded that, growing cattle treated with two injections of doramectin (200 mcg/ kg) administered 56 days apart had better productivity and parasite control over a 140-day period, than cattle treated with a single injection of ivermectin (630 mcg/kg).
OBJECTIVE: The objective of this study was to verify the occurrence of vitamin A deficiency in sc... more OBJECTIVE: The objective of this study was to verify the occurrence of vitamin A deficiency in school children of the rural area of Novo Cruzeiro, Minas Gerais, Brazil, as well as to identify the possible predisposing factors for such occurrence. METHODS: The sample comprised 241 school children, ranging from 6 to 14 years of age, from four rural schools of the region. The serum levels of retinol were interpreted by the criteria of the Interdepartmental Committee on Nutrition National Defense. The epidemiological significance of the vitamin A deficiency was evaluated according to the World Health Organization criteria. As predisposing factors for vitamin A deficiency, the following conditions were considered: intestinal parasitism, protein-energy malnutrition, inadequate ingestion of vitamin A food sources, and per capita family income. Statistical analysis was carried out using Chi-square test. RESULTS: Vitamin A deficiency was identified in 29.0% of the subjects, 23.2% of the chil...
Abstract Text: The aim of this study was to obtain genetic parameters for resistance to ticks, ga... more Abstract Text: The aim of this study was to obtain genetic parameters for resistance to ticks, gastrointestinal nematodes and Eimeria spp. in Nellore cattle using random regression models through Bayesian inference. Animals were classified as resistant or susceptible for each parasite. Heritability estimates ranged from low to high magnitude (0.07 to 0.30 for resistance to ticks, 0.02 to 0.34 for resistance to gastrointestinal nematodes, and from 0.04 to 0.39 for resistance Eimeria spp.) In general, the posterior means of genetic correlations between resistance characteristics were low while high density intervals were large, and in many cases included zero. Thus, there is genetic variation in resistance traits in Nelore cattle and these may be included in breeding programs. The selection may increase the frequency of resistant animals in any age evaluated in this study. Keywords: beef cattle correlation heritability resistance
Revista Brasileira de Parasitologia Veterinária, 2011
Semi-systematized interviews were conducted with 100 dairy cattle producers in the municipality o... more Semi-systematized interviews were conducted with 100 dairy cattle producers in the municipality of Divinópolis, Minas Gerais, with the aim of ascertaining their perceptions regarding the importance of Rhipicephalus (Boophilus) microplus and of combating it. Content analysis was performed and the frequency distribution of each of the variables was used to construct profiles of the producers interviewed. The production losses caused by ticks were perceived incompletely by the producers, who were unaware of the pathogen transmission caused by the parasite and the indirect losses through combating it, such as the cost of acaricide and labor. The combat operations were performed in a traditional manner, with an excessive number of inefficient treatments that aimed to control the level of infestation at that moment. The quality of the acaricide dipping/spraying applied was affected by the quality of the equipment used to apply the products, lack of knowledge of the mode of action of these...
Revista Brasileira de Parasitologia Veterinária, 2010
Amblyomma rotundatum is an ixodid tick that infests ectothermic animals and reproduces exclusivel... more Amblyomma rotundatum is an ixodid tick that infests ectothermic animals and reproduces exclusively by parthenogenesis. This tick has been frequently reported to infest reptiles and amphibians, under natural conditions and sometimes in captivity. It was described in Brazil and several other countries of South, Central and North America. Although many studies have reported aspects of its biology, none of them has used regularly either ophidian as hosts, or controlled temperature, humidity and luminosity for parasitic stages. The objective of this experiment was to study the life cycle of A. rotundatum feeding on Viperidae snakes under room controlled conditions at 27 ± 1 ºC temperature, 85 ± 10% relative humidity and 12:12 hours photoperiod for parasitic stages, and under B.O.D incubator conditions at 27 ± 1 ºC temperature, 85 ± 10% relative humidity and scotophase for non-parasitic stages. The total duration of the life cycle ranged from 56 to 163 days (mean of 105 days). Two-host li...
The objective of this study was to verify the effect of the urea fertilization in pasture on Rhip... more The objective of this study was to verify the effect of the urea fertilization in pasture on Rhipicephalus (Boophilus) microplus population in free living stage. Two groups had been made, a control group and a urea treatment group, each group with 10 lots of Mombaça grass (Panicum maximum cv. Mombaça). In day zero had been placed 12 engorged tick females in each lot and made fertilization with urea in the dosage of 60g in the lots of the treat group. In 27 th day the grass was cutted out in 1 to 5 lots of both groups and fertilized with urea in the lots of 1 to 5 in the treat group. In 40 th day was released a white flannel 1.60 x 1.00m length on each lot to verify the presence of larvae. The results presented a difference of 85.97% (P<0.0001) between the treat group and the control group.
Os búfalos apresentam susceptibilidade a maioria dos parasitos já descritos parasitando bovinos a... more Os búfalos apresentam susceptibilidade a maioria dos parasitos já descritos parasitando bovinos além de outros específicos dos búfalos, como o Haematopinus tuberculatus, Paracooperia nodulosa e Eimeria bareillyi. O conhecimento das características epidemiológicas e da patogenia de cada parasito é indispensável para estabelecer programas de controle parasitário eficientes nos rebanhos de búfalos em todo o mundo.
Revista Brasileira de Parasitologia Veterinária, 2011
This study reports rickettsial infection in Amblyomma cajennense and Amblyomma dubitatum ticks co... more This study reports rickettsial infection in Amblyomma cajennense and Amblyomma dubitatum ticks collected in an area of the state of Minas Gerais, Brazil, where Brazilian spotted fever is considered endemic. For this purpose, 400 adults of A. cajenennse and 200 adults of A. dubitatum, plus 2,000 larvae and 2,000 nymphs of Amblyomma spp. were collected from horses and from the vegetation. The ticks were tested for rickettsial infection through polymerase chain reaction (PCR) protocols targeting portions of three rickettsial genes (gltA, ompA, and ompB). Only two free-living A. cajennense adult ticks, and four pools of free-living Amblyomma spp. nymphs were shown to contain rickettsial DNA. PCR products from the two A. cajennense adult ticks were shown to be identical to corresponding sequences of the Rickettsia rickettsii strain Sheila Smith. DNA sequences of gltA-PCR products of the four nymph pools of Amblyomma spp. revealed a new genotype, which was shown to be closest (99.4%) to t...
The gastrointestinal parasitoses of domestic animals have a great impact on the hematological sta... more The gastrointestinal parasitoses of domestic animals have a great impact on the hematological status but nonetheless research on this subject concerning buffaloes is rare. Thus, the blood profile of buffalo calves naturally infected by parasites from the seventh to the 300 th day of life. Animals were distributed in three experimental groups treated with ivermectin, fenbendazole, and placebo, respectively. Changes of hematological parameters were related to the presence of adult gastrointestinal nematodes, which were diagnosed and identified by the presence of eggs in the feces of wormed animals as compared to those medicated.
Avaliou-se quantitativamente as infestações por adultos de Amblyomma cajennense em eqüinos mantid... more Avaliou-se quantitativamente as infestações por adultos de Amblyomma cajennense em eqüinos mantidos sob infestações naturais em uma pastagem (pastagem 1), antes e após o uso de tratamentos carrapaticidas. Os tratamentos foram aplicados nos eqüinos a cada sete dias durante os períodos de predomínio das larvas e ninfas do carrapato, no Estado de São Paulo (abril a outubro). Nos eqüinos mantidos em outra pastagem (pastagem 2), os tratamentos foram realizados, também a cada sete dias, mas de abril a julho, época de predomínio das larvas de A. cajennense. Todos os banhos carrapaticidas foram realizados com carrapaticida comercial à base do piretróide alfametrina. A redução da carga de carrapatos adultos após os banhos carrapaticidas foi de 89,7 e 58,6% nos eqüinos alocados nas pastagens 1 e 2, respectivamente. A redução das fêmeas adultas foi ainda mais expressiva (95,4 e 69,0% para os eqüinos das pastagens 1 e 2, respectivamente). Os resultados comprovam a eficácia de uma proposta de co...
The present study was performed in an area endemic for Brazilian spotted fever (BSF) in Juiz de F... more The present study was performed in an area endemic for Brazilian spotted fever (BSF) in Juiz de Fora, state of Minas Gerais, Brazil, during the years 2007 and 2008, when fatal cases of BSF (caused by Rickettsia rickettsii) were reported. Adult ticks (Acari: Ixodidae) identified as Rhipicephalus sanguineus (Latreille) and Amblyomma cajennense (Fabricius) were collected from dogs and horses, respectively, and tested by polymerase chain reaction (PCR). Overall, 13.1% of the Rh. sanguineus ticks and none of the A. cajennense were found to be infected with R. rickettsii. Two isolates of R. rickettsii were successfully established in Vero cell culture from two Rh. sanguineus ticks. An indirect immunofluorescence assay (IFA) using R. rickettsii antigens detected blood serological reaction to R. rickettsii in 67.9% (53/78) of dogs and 41.0% (16/39) of horses living in the study area. Larval offspring from two Rh. sanguineus engorged females, naturally infected by R. rickettsii, were reared to adult stage in the laboratory. All active stages (larvae, nymphs, adults) remained 100% infected by R. rickettsii, which was efficiently transmitted to naïve rabbits. Overall, the results of the present study indicate a potential risk for transmission of R. rickettsii to humans by Rh. sanguineus, an occurrence yet to be documented in Brazil.
An outbreak of Malignant Catarrhal Fever (MCF) resulting in death of 5 buffaloes in the same farm... more An outbreak of Malignant Catarrhal Fever (MCF) resulting in death of 5 buffaloes in the same farm. Four buffaloes died 10-15 days after the beginning of the signals and the another one was euthanized in extremus, after similar signals. Histopathological examination showed lesions suggestive to MCF in buffaloes such as epicarditis and multifocal miocarditis with infiltrates of mononuclear lymphocytes and macrophages besides lymphocytic interstitial pneumonia. PCR revealed 98% homology between an amplified fragment obtained from the CNS of the buffaloes and specific sequences of OHV-2. Diagnosis of MCF was firmed in epidemiological, clinical, gross and histopathological findings and in results of a semi-nested PCR.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2005
Foram realizados dois testes de redução de ovos de helmintos por grama de fezes em bovinos natura... more Foram realizados dois testes de redução de ovos de helmintos por grama de fezes em bovinos naturalmente infectados. No primeiro teste utilizaram-se quatro grupos tratados: ivermectina 1% (IVM), produto endectocida experimental (PEE), ivermectina LA 1% (IVMLA) e doramectina 1% (DRM). A contagem de ovos por gramas de fezes (OPG) foi realizada durante 14 dias pós-tratamento. Foram observadas as seguintes taxas de eficácia: IVM, -1,3%; PEE, 100%; IVMLA, 18,9% e DRM 50,6%. Os gêneros de helmintos encontrados foram Cooperia e Haemonchus. No segundo teste foram avaliadas moxidectina 1% e abamectina 1%, e ambas apresentaram eficácia acima de 99%.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2009
The development of acquired resistance to Amblyomma cajennense ticks was evaluated. A total of 18... more The development of acquired resistance to Amblyomma cajennense ticks was evaluated. A total of 18 rabbits were uniformly distributed into three groups named GL, GN, and GA that were submitted to three consecutive infestations with, respectively, larvae, nymphs, and adults of A. cajennense. After the infestations, the parasitic and reproductive parameters of recovered instars were evaluated. A significant reduction of recovery rates of inoculated ticks was observed only after the third infestation of animals in groups GL and GN (P<0.01). The modal day for drop-off of engorged larvae and nymphs increased along the infestations. The recovered engorged nymphs presented a significant reduction of the mean body weight between the first and the third infestations (P<0.01). A significant reduction in the mean recovery rate of engorged females was only observed during the third infestation. However, significant reductions (P<0.05) in body weight, egg mass weight, and larva eclosions...
This study aims to establish the hematological values of Crotalus durissus collilineatus snakes c... more This study aims to establish the hematological values of Crotalus durissus collilineatus snakes captured in Brazil as well as to verify the effects of hematozoan infection on these snakes. Eighty-three blood samples were drawn from C. d. collilineatus specimens for analysis. The sample set was composed of 30 males and 30 females, recently caught from the wild, and 11 males and 12 females bred in captivity. Blood samples were used to determine red blood cell counts, white blood cell counts, thrombocyte counts, hematocrit values, hemoglobin concentration, and total plasma protein. Blood smears were used to diagnose Hepatozoon spp. infection and to calculate the parasitic load in the sample as well as the percentage of immature red cells. Results obtained for the wild-caught animals, with and without parasites, were compared among themselves and with the values obtained for the captive-bred animals. Hematological values for C. durissus were established. Wild-caught snakes had an infection rate of 38.3%, while no Hepatozoon sp. infection was detected in the captive-bred animals. The snakes which were not infected by the Hepatozoon sp. exhibited average weight, length, and weight-length ratios higher than those of the infected animals. An increase in immature red cells was noted in the Hepatozoon-infected snakes.
Revista Brasileira De Parasitologia Veterinaria, 2008
A study on the population behavior of Amblyomma cajennense and Amblyomma dubitatum larvae, nymphs... more A study on the population behavior of Amblyomma cajennense and Amblyomma dubitatum larvae, nymphs andadult free-living stages was carried out in Coronel Pach...
Trabalho realizado pelo Departamento de Nutrição Clínica e Social da UFOP em parceria com a UFMG,... more Trabalho realizado pelo Departamento de Nutrição Clínica e Social da UFOP em parceria com a UFMG, com recursos das instituições: UFOP e UFMG. Baseado em dissertação: "Anemia ferropriva e seus fatores predisponentes, em escolares da área rural
, to compare the anti-parasitic efficacy and productivity effects of 2 subcutaneous injections of... more , to compare the anti-parasitic efficacy and productivity effects of 2 subcutaneous injections of doramectin (200 mcg/kg) administered 56 days apart with that of a single injection of ivermectin (630 mcg/kg) in growing cattle. Ninety-six crossbred male cattle were randomly allocated to 3 groups of 32 animals, based on bodyweight. All animals grazed the same pasture during the study. Treatments consisted of either 2 injections of doramectin (days 0 and 56), one injection of ivermectin (day 0), or no treatment (controls). Cattle weight, nematode egg counts, coprocultures, tick counts, tropical warble nodule counts, and presence of screw worms were determined on days 0, 28, 56, 84, 112 and 140. Mean fecal egg counts from cattle in both medicated groups were significantly reduced compared to those of controls. Coprocultures showed a predominance of Cooperia spp. and Haemonchus spp. On days 84 and 112, fecal egg counts of doramectin-treated cattle were significantly (p<0.05) lower than those for ivermectin-treated cattle. Tick counts were also reduced in the doramectin-and ivermectin-treatment groups compared to those for controls. On day 84, ticks counts of doramectin-treated cattle were significantly lower than those of ivermectin-treated cattle. At the end of the 140-day study, doramectin-treated cattle had a mean weight gain of 11.3 kg and 14.1 kg higher than that of ivermectin-treated cattle (p<0.05) and controls (p<0.05), respectively. It is concluded that, growing cattle treated with two injections of doramectin (200 mcg/ kg) administered 56 days apart had better productivity and parasite control over a 140-day period, than cattle treated with a single injection of ivermectin (630 mcg/kg).
OBJECTIVE: The objective of this study was to verify the occurrence of vitamin A deficiency in sc... more OBJECTIVE: The objective of this study was to verify the occurrence of vitamin A deficiency in school children of the rural area of Novo Cruzeiro, Minas Gerais, Brazil, as well as to identify the possible predisposing factors for such occurrence. METHODS: The sample comprised 241 school children, ranging from 6 to 14 years of age, from four rural schools of the region. The serum levels of retinol were interpreted by the criteria of the Interdepartmental Committee on Nutrition National Defense. The epidemiological significance of the vitamin A deficiency was evaluated according to the World Health Organization criteria. As predisposing factors for vitamin A deficiency, the following conditions were considered: intestinal parasitism, protein-energy malnutrition, inadequate ingestion of vitamin A food sources, and per capita family income. Statistical analysis was carried out using Chi-square test. RESULTS: Vitamin A deficiency was identified in 29.0% of the subjects, 23.2% of the chil...
Abstract Text: The aim of this study was to obtain genetic parameters for resistance to ticks, ga... more Abstract Text: The aim of this study was to obtain genetic parameters for resistance to ticks, gastrointestinal nematodes and Eimeria spp. in Nellore cattle using random regression models through Bayesian inference. Animals were classified as resistant or susceptible for each parasite. Heritability estimates ranged from low to high magnitude (0.07 to 0.30 for resistance to ticks, 0.02 to 0.34 for resistance to gastrointestinal nematodes, and from 0.04 to 0.39 for resistance Eimeria spp.) In general, the posterior means of genetic correlations between resistance characteristics were low while high density intervals were large, and in many cases included zero. Thus, there is genetic variation in resistance traits in Nelore cattle and these may be included in breeding programs. The selection may increase the frequency of resistant animals in any age evaluated in this study. Keywords: beef cattle correlation heritability resistance
Revista Brasileira de Parasitologia Veterinária, 2011
Semi-systematized interviews were conducted with 100 dairy cattle producers in the municipality o... more Semi-systematized interviews were conducted with 100 dairy cattle producers in the municipality of Divinópolis, Minas Gerais, with the aim of ascertaining their perceptions regarding the importance of Rhipicephalus (Boophilus) microplus and of combating it. Content analysis was performed and the frequency distribution of each of the variables was used to construct profiles of the producers interviewed. The production losses caused by ticks were perceived incompletely by the producers, who were unaware of the pathogen transmission caused by the parasite and the indirect losses through combating it, such as the cost of acaricide and labor. The combat operations were performed in a traditional manner, with an excessive number of inefficient treatments that aimed to control the level of infestation at that moment. The quality of the acaricide dipping/spraying applied was affected by the quality of the equipment used to apply the products, lack of knowledge of the mode of action of these...
Revista Brasileira de Parasitologia Veterinária, 2010
Amblyomma rotundatum is an ixodid tick that infests ectothermic animals and reproduces exclusivel... more Amblyomma rotundatum is an ixodid tick that infests ectothermic animals and reproduces exclusively by parthenogenesis. This tick has been frequently reported to infest reptiles and amphibians, under natural conditions and sometimes in captivity. It was described in Brazil and several other countries of South, Central and North America. Although many studies have reported aspects of its biology, none of them has used regularly either ophidian as hosts, or controlled temperature, humidity and luminosity for parasitic stages. The objective of this experiment was to study the life cycle of A. rotundatum feeding on Viperidae snakes under room controlled conditions at 27 ± 1 ºC temperature, 85 ± 10% relative humidity and 12:12 hours photoperiod for parasitic stages, and under B.O.D incubator conditions at 27 ± 1 ºC temperature, 85 ± 10% relative humidity and scotophase for non-parasitic stages. The total duration of the life cycle ranged from 56 to 163 days (mean of 105 days). Two-host li...
The objective of this study was to verify the effect of the urea fertilization in pasture on Rhip... more The objective of this study was to verify the effect of the urea fertilization in pasture on Rhipicephalus (Boophilus) microplus population in free living stage. Two groups had been made, a control group and a urea treatment group, each group with 10 lots of Mombaça grass (Panicum maximum cv. Mombaça). In day zero had been placed 12 engorged tick females in each lot and made fertilization with urea in the dosage of 60g in the lots of the treat group. In 27 th day the grass was cutted out in 1 to 5 lots of both groups and fertilized with urea in the lots of 1 to 5 in the treat group. In 40 th day was released a white flannel 1.60 x 1.00m length on each lot to verify the presence of larvae. The results presented a difference of 85.97% (P<0.0001) between the treat group and the control group.
Os búfalos apresentam susceptibilidade a maioria dos parasitos já descritos parasitando bovinos a... more Os búfalos apresentam susceptibilidade a maioria dos parasitos já descritos parasitando bovinos além de outros específicos dos búfalos, como o Haematopinus tuberculatus, Paracooperia nodulosa e Eimeria bareillyi. O conhecimento das características epidemiológicas e da patogenia de cada parasito é indispensável para estabelecer programas de controle parasitário eficientes nos rebanhos de búfalos em todo o mundo.
Revista Brasileira de Parasitologia Veterinária, 2011
This study reports rickettsial infection in Amblyomma cajennense and Amblyomma dubitatum ticks co... more This study reports rickettsial infection in Amblyomma cajennense and Amblyomma dubitatum ticks collected in an area of the state of Minas Gerais, Brazil, where Brazilian spotted fever is considered endemic. For this purpose, 400 adults of A. cajenennse and 200 adults of A. dubitatum, plus 2,000 larvae and 2,000 nymphs of Amblyomma spp. were collected from horses and from the vegetation. The ticks were tested for rickettsial infection through polymerase chain reaction (PCR) protocols targeting portions of three rickettsial genes (gltA, ompA, and ompB). Only two free-living A. cajennense adult ticks, and four pools of free-living Amblyomma spp. nymphs were shown to contain rickettsial DNA. PCR products from the two A. cajennense adult ticks were shown to be identical to corresponding sequences of the Rickettsia rickettsii strain Sheila Smith. DNA sequences of gltA-PCR products of the four nymph pools of Amblyomma spp. revealed a new genotype, which was shown to be closest (99.4%) to t...
The gastrointestinal parasitoses of domestic animals have a great impact on the hematological sta... more The gastrointestinal parasitoses of domestic animals have a great impact on the hematological status but nonetheless research on this subject concerning buffaloes is rare. Thus, the blood profile of buffalo calves naturally infected by parasites from the seventh to the 300 th day of life. Animals were distributed in three experimental groups treated with ivermectin, fenbendazole, and placebo, respectively. Changes of hematological parameters were related to the presence of adult gastrointestinal nematodes, which were diagnosed and identified by the presence of eggs in the feces of wormed animals as compared to those medicated.
Avaliou-se quantitativamente as infestações por adultos de Amblyomma cajennense em eqüinos mantid... more Avaliou-se quantitativamente as infestações por adultos de Amblyomma cajennense em eqüinos mantidos sob infestações naturais em uma pastagem (pastagem 1), antes e após o uso de tratamentos carrapaticidas. Os tratamentos foram aplicados nos eqüinos a cada sete dias durante os períodos de predomínio das larvas e ninfas do carrapato, no Estado de São Paulo (abril a outubro). Nos eqüinos mantidos em outra pastagem (pastagem 2), os tratamentos foram realizados, também a cada sete dias, mas de abril a julho, época de predomínio das larvas de A. cajennense. Todos os banhos carrapaticidas foram realizados com carrapaticida comercial à base do piretróide alfametrina. A redução da carga de carrapatos adultos após os banhos carrapaticidas foi de 89,7 e 58,6% nos eqüinos alocados nas pastagens 1 e 2, respectivamente. A redução das fêmeas adultas foi ainda mais expressiva (95,4 e 69,0% para os eqüinos das pastagens 1 e 2, respectivamente). Os resultados comprovam a eficácia de uma proposta de co...
The present study was performed in an area endemic for Brazilian spotted fever (BSF) in Juiz de F... more The present study was performed in an area endemic for Brazilian spotted fever (BSF) in Juiz de Fora, state of Minas Gerais, Brazil, during the years 2007 and 2008, when fatal cases of BSF (caused by Rickettsia rickettsii) were reported. Adult ticks (Acari: Ixodidae) identified as Rhipicephalus sanguineus (Latreille) and Amblyomma cajennense (Fabricius) were collected from dogs and horses, respectively, and tested by polymerase chain reaction (PCR). Overall, 13.1% of the Rh. sanguineus ticks and none of the A. cajennense were found to be infected with R. rickettsii. Two isolates of R. rickettsii were successfully established in Vero cell culture from two Rh. sanguineus ticks. An indirect immunofluorescence assay (IFA) using R. rickettsii antigens detected blood serological reaction to R. rickettsii in 67.9% (53/78) of dogs and 41.0% (16/39) of horses living in the study area. Larval offspring from two Rh. sanguineus engorged females, naturally infected by R. rickettsii, were reared to adult stage in the laboratory. All active stages (larvae, nymphs, adults) remained 100% infected by R. rickettsii, which was efficiently transmitted to naïve rabbits. Overall, the results of the present study indicate a potential risk for transmission of R. rickettsii to humans by Rh. sanguineus, an occurrence yet to be documented in Brazil.
An outbreak of Malignant Catarrhal Fever (MCF) resulting in death of 5 buffaloes in the same farm... more An outbreak of Malignant Catarrhal Fever (MCF) resulting in death of 5 buffaloes in the same farm. Four buffaloes died 10-15 days after the beginning of the signals and the another one was euthanized in extremus, after similar signals. Histopathological examination showed lesions suggestive to MCF in buffaloes such as epicarditis and multifocal miocarditis with infiltrates of mononuclear lymphocytes and macrophages besides lymphocytic interstitial pneumonia. PCR revealed 98% homology between an amplified fragment obtained from the CNS of the buffaloes and specific sequences of OHV-2. Diagnosis of MCF was firmed in epidemiological, clinical, gross and histopathological findings and in results of a semi-nested PCR.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2005
Foram realizados dois testes de redução de ovos de helmintos por grama de fezes em bovinos natura... more Foram realizados dois testes de redução de ovos de helmintos por grama de fezes em bovinos naturalmente infectados. No primeiro teste utilizaram-se quatro grupos tratados: ivermectina 1% (IVM), produto endectocida experimental (PEE), ivermectina LA 1% (IVMLA) e doramectina 1% (DRM). A contagem de ovos por gramas de fezes (OPG) foi realizada durante 14 dias pós-tratamento. Foram observadas as seguintes taxas de eficácia: IVM, -1,3%; PEE, 100%; IVMLA, 18,9% e DRM 50,6%. Os gêneros de helmintos encontrados foram Cooperia e Haemonchus. No segundo teste foram avaliadas moxidectina 1% e abamectina 1%, e ambas apresentaram eficácia acima de 99%.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2009
The development of acquired resistance to Amblyomma cajennense ticks was evaluated. A total of 18... more The development of acquired resistance to Amblyomma cajennense ticks was evaluated. A total of 18 rabbits were uniformly distributed into three groups named GL, GN, and GA that were submitted to three consecutive infestations with, respectively, larvae, nymphs, and adults of A. cajennense. After the infestations, the parasitic and reproductive parameters of recovered instars were evaluated. A significant reduction of recovery rates of inoculated ticks was observed only after the third infestation of animals in groups GL and GN (P<0.01). The modal day for drop-off of engorged larvae and nymphs increased along the infestations. The recovered engorged nymphs presented a significant reduction of the mean body weight between the first and the third infestations (P<0.01). A significant reduction in the mean recovery rate of engorged females was only observed during the third infestation. However, significant reductions (P<0.05) in body weight, egg mass weight, and larva eclosions...
This study aims to establish the hematological values of Crotalus durissus collilineatus snakes c... more This study aims to establish the hematological values of Crotalus durissus collilineatus snakes captured in Brazil as well as to verify the effects of hematozoan infection on these snakes. Eighty-three blood samples were drawn from C. d. collilineatus specimens for analysis. The sample set was composed of 30 males and 30 females, recently caught from the wild, and 11 males and 12 females bred in captivity. Blood samples were used to determine red blood cell counts, white blood cell counts, thrombocyte counts, hematocrit values, hemoglobin concentration, and total plasma protein. Blood smears were used to diagnose Hepatozoon spp. infection and to calculate the parasitic load in the sample as well as the percentage of immature red cells. Results obtained for the wild-caught animals, with and without parasites, were compared among themselves and with the values obtained for the captive-bred animals. Hematological values for C. durissus were established. Wild-caught snakes had an infection rate of 38.3%, while no Hepatozoon sp. infection was detected in the captive-bred animals. The snakes which were not infected by the Hepatozoon sp. exhibited average weight, length, and weight-length ratios higher than those of the infected animals. An increase in immature red cells was noted in the Hepatozoon-infected snakes.
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