PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Diel D.G., Fonseca E.T., Souza S.F., Mazzanti A., Bauermann F., Weiblen R. & Flores E.F. 2005. [Bovine herpesvirus 5 may use the olfactory and trigeminal pathways to invade the central nervous system of rabbits, depending upon the route of inoculation.] O Herpesvírus bovino tipo 5 (BoHV-5) pode utilizar as rotas olfatória ou trigeminal para invadir o sistema nervoso central de coelhos, dependendo da via de inoculação. Pesquisa Veterinária Brasileira 25(3):164-170. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: flores@ccr.ufsm.br Bovine herpesvirus type 5 (BoHV-5) is a major etiological agent of meningoencephalitis in cattle. Following replication in the nasal mucosa, viral invasion of the brain is thought to occur mainly by the olfactory pathway. To address the role of this pathway in the pathogenesis of neurological infection in a laboratory model, 30 days old rabbits had the main olfactory bulbs (MOBs) surgically removed and were subsequently inoculated intranasally (IN) or conjunctivally (IC) with a highly neurovirulent BoHV-5 strain (SV-507). Following IN inoculation, 10 out of 10 (100 %) control rabbits developed neurological disease. The clinical onset ranged from day 5 to 10 post-inoculation (pi, average 7.5 days); nine being euthanized in extremis and one recovering after a mild clinical course. In contrast, only one rabbit (9.1 %) of the group lacking the MOBs (n=11) developed neurological disease (onset at day 17 pi). Dexamethasone administration to the survivors (n=10) at day 50pi was followed by virus shedding in nasal and/or ocular secretions by 8 animals, demonstrating that the virus was able to reach the trigeminal ganglia (TG) during acute infection. These results demonstrate that the olfactory route provides the main, yet not the sole access to the brain of rabbits following IN inoculation. To address the role of a second pathway, groups of control (n=12) or MOB-lacking rabbits (n=12) were inoculated into the conjunctival sac (IC), following which the virus would be expected to use the ophtalmic branch of the trigeminal nerve to reach the brain. Ten control rabbits (83.3 %) developed neurological disease upon IC inoculation (onset 15.3 days [11 to 20]). Previous ablation of the MOBs did not affect the frequency and course of neurological disease: ten out of 12 rabbits (83.3 %) lacking the MOBs developed neurological disease (onset 9 to 15 dpi, average: 12.7 days) upon IC inoculation. These results demonstrate that both IN and IC routes may operate in the transport of BoHV-5 to the brain of experimentally infected rabbits, depending on the route of inoculation. IN inoculation results in a fast and efficient transport by the olfactory pathway, the trigeminal route providing an alternative, much slower and less efficient transport; IC inoculation results in efficient viral transport by the trigeminal route, yet with a delayed kinetics comparing to the transport provided by the olfactory pathway.

• Bovine herpesvirus type 5 BoHV-5 neurological infection rabbits.

Abstract in Portuguese:

Diel D.G., Fonseca E.T., Souza S.F., Mazzanti A., Bauermann F., Weiblen R. & Flores E.F. 2005. [Bovine herpesvirus 5 may use the olfactory and trigeminal pathways to invade the central nervous system of rabbits, depending upon the route of inoculation.] O Herpesvírus bovino tipo 5 (BoHV-5) pode utilizar as rotas olfatória ou trigeminal para invadir o sistema nervoso central de coelhos, dependendo da via de inoculação. Pesquisa Veterinária Brasileira 25(3):164-170. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: flores@ccr.ufsm.br Bovine herpesvirus type 5 (BoHV-5) is a major etiological agent of meningoencephalitis in cattle. Following replication in the nasal mucosa, viral invasion of the brain is thought to occur mainly by the olfactory pathway. To address the role of this pathway in the pathogenesis of neurological infection in a laboratory model, 30 days old rabbits had the main olfactory bulbs (MOBs) surgically removed and were subsequently inoculated intranasally (IN) or conjunctivally (IC) with a highly neurovirulent BoHV-5 strain (SV-507). Following IN inoculation, 10 out of 10 (100 %) control rabbits developed neurological disease. The clinical onset ranged from day 5 to 10 post-inoculation (pi, average 7.5 days); nine being euthanized in extremis and one recovering after a mild clinical course. In contrast, only one rabbit (9.1 %) of the group lacking the MOBs (n=11) developed neurological disease (onset at day 17 pi). Dexamethasone administration to the survivors (n=10) at day 50pi was followed by virus shedding in nasal and/or ocular secretions by 8 animals, demonstrating that the virus was able to reach the trigeminal ganglia (TG) during acute infection. These results demonstrate that the olfactory route provides the main, yet not the sole access to the brain of rabbits following IN inoculation. To address the role of a second pathway, groups of control (n=12) or MOB-lacking rabbits (n=12) were inoculated into the conjunctival sac (IC), following which the virus would be expected to use the ophtalmic branch of the trigeminal nerve to reach the brain. Ten control rabbits (83.3 %) developed neurological disease upon IC inoculation (onset 15.3 days [11 to 20]). Previous ablation of the MOBs did not affect the frequency and course of neurological disease: ten out of 12 rabbits (83.3 %) lacking the MOBs developed neurological disease (onset 9 to 15 dpi, average: 12.7 days) upon IC inoculation. These results demonstrate that both IN and IC routes may operate in the transport of BoHV-5 to the brain of experimentally infected rabbits, depending on the route of inoculation. IN inoculation results in a fast and efficient transport by the olfactory pathway, the trigeminal route providing an alternative, much slower and less efficient transport; IC inoculation results in efficient viral transport by the trigeminal route, yet with a delayed kinetics comparing to the transport provided by the olfactory pathway.

Abstract in English:

Flores E.F., Weiblen R., Vogel F.S.F., Roehe P.M., Alfieri A.A. & Pituco E.M. 2005. [Bovine viral diarrhea virus (BVDV) infection in Brazil: history, current situation and perspectives.] A infecção pelo vírus da Diarréia Viral Bovina (BVDV) no Brasil - histórico, situação atual e perspectivas. Pesquisa Veterinária Brasileira 25(3):125-134. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: flores@ccr.ufsm.br Bovine viral diarrhea virus (BVDV) is one of the most important pathogens of cattle worldwide. BVDV infection and associated diseases have been reported in Brazil since the late 1960ties. Several serological, virological, clinical and pathological reports demonstrate the widespread distribution of BVDV infection among Brazilian cattle. In addition to variable levels of positive serology in beef and dairy cattle, BVDV antibodies have been occasionally detected in swine, wild boars, goats, cervids and water buffaloes. BVDV infection has been diagnosed in aborted fetuses, buffy coats of persistently infected (PI) animals, clinical specimens from animals suffering from different clinical syndromes, semen of bulls of artificial insemination (AI) centers, in healthy fetuses and in commercial fetal bovine serum and/or cultured cells. About 50 isolates have been genetically and/or antigenically characterized up to date, whilst roughly an equivalent number of isolates awaits characterization. Most of the characterized isolates belong to BVDV-1 genotype, non-cytopathic (NCP) biotype, yet some BVDV-2 (and some CP BVDV) have been identified as well. Brazilian BVDV isolates display a high antigenic variability and are markedly different from North American vaccine strains. A few inactivated, polyvalent vaccines are currently licensed in the country, yet vaccination is still incipient in many regions: only about 2.5 million doses were marketed in 2003. The low serological cross-reactivity between vaccine strains and field isolates has recently stimulated national industries to develop vaccines containing Brazilian BVDV-1 and BVDV-2 strains. The overall knowledge about BVDV infection in Brazil has grown considerably in the last years, due to an increasing number of laboratories performing diagnosis and research. Studies on the pathogenesis, serological and molecular epidemiology and production of reagents for diagnosis have contributed decisively for the recent growing knowledge on BVDV infections in the country.

• Bovine viral diarrhea virus BVDV epidemiology diagnostic.

Abstract in Portuguese:

Flores E.F., Weiblen R., Vogel F.S.F., Roehe P.M., Alfieri A.A. & Pituco E.M. 2005. [Bovine viral diarrhea virus (BVDV) infection in Brazil: history, current situation and perspectives.] A infecção pelo vírus da Diarréia Viral Bovina (BVDV) no Brasil - histórico, situação atual e perspectivas. Pesquisa Veterinária Brasileira 25(3):125-134. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: flores@ccr.ufsm.br Bovine viral diarrhea virus (BVDV) is one of the most important pathogens of cattle worldwide. BVDV infection and associated diseases have been reported in Brazil since the late 1960ties. Several serological, virological, clinical and pathological reports demonstrate the widespread distribution of BVDV infection among Brazilian cattle. In addition to variable levels of positive serology in beef and dairy cattle, BVDV antibodies have been occasionally detected in swine, wild boars, goats, cervids and water buffaloes. BVDV infection has been diagnosed in aborted fetuses, buffy coats of persistently infected (PI) animals, clinical specimens from animals suffering from different clinical syndromes, semen of bulls of artificial insemination (AI) centers, in healthy fetuses and in commercial fetal bovine serum and/or cultured cells. About 50 isolates have been genetically and/or antigenically characterized up to date, whilst roughly an equivalent number of isolates awaits characterization. Most of the characterized isolates belong to BVDV-1 genotype, non-cytopathic (NCP) biotype, yet some BVDV-2 (and some CP BVDV) have been identified as well. Brazilian BVDV isolates display a high antigenic variability and are markedly different from North American vaccine strains. A few inactivated, polyvalent vaccines are currently licensed in the country, yet vaccination is still incipient in many regions: only about 2.5 million doses were marketed in 2003. The low serological cross-reactivity between vaccine strains and field isolates has recently stimulated national industries to develop vaccines containing Brazilian BVDV-1 and BVDV-2 strains. The overall knowledge about BVDV infection in Brazil has grown considerably in the last years, due to an increasing number of laboratories performing diagnosis and research. Studies on the pathogenesis, serological and molecular epidemiology and production of reagents for diagnosis have contributed decisively for the recent growing knowledge on BVDV infections in the country.

Abstract in English:

Catto J.B., Bianchin I., Torres Junior R.A.A. 2005. [Effects of deworming of cow-calf beef herds in brazilian savannas.] Efeitos da everminação de matrizes e de bezerros lactentes em sistema de produção de bovinos de corte na região de Cerrado. Pesquisa Veterinária Brasileira 25(3):188-194. Embrapa Gado de Corte, Rodov. 162, Km 4, Campo Grande, MS 79002-950, Brazil. E-mail: catto@cnpgc.embrapa.br The effect of deworming with ivermectin of cows before calving and of suckling calves on fecal egg counts (EPG) and productive performance of two beef cattle herds in Central Brazil was studied. Four groups of pregnant cows received the following treatments: T1- cows and calves not treated, T2- only calves treated, T3- only cows treated, and T4- cows and calves treated. The calves of T2 and T4 were distributed in the following treatments: A- calves treated at 3 to 5 months of age with long action ivermectin, B- treated with ivermectin, and C- control. For the cows, the deworming did not diminish the EPG during lactation and also did not have significant effect on the conception rate, live weight gain and the body weight of their calves at 3 to 5 months of age. The calves of treatment A gained, from the time of treatment to weaning (84 to 108 days), an average of 4.2kg (P=0.0003) and 7.1kg (P<0.0001) more than those of treatment B and C, respectively. The average difference in live weight gain of 2.9kg between the animals of treatment B and C was not significant. The EPG before treatment was not significantly different from the treatments (P=0.8665); but at weaning, the average EPG of the calves from treatment A was lower than for treatment B (P=0.0004) and C (P<0.0001). There was no significant difference in the mean EPG for the calves from treatment B and C.

• Beef cattle cows suckling calves nematodes treatment Brazilian savannas.

Abstract in Portuguese:

Catto J.B., Bianchin I., Torres Junior R.A.A. 2005. [Effects of deworming of cow-calf beef herds in brazilian savannas.] Efeitos da everminação de matrizes e de bezerros lactentes em sistema de produção de bovinos de corte na região de Cerrado. Pesquisa Veterinária Brasileira 25(3):188-194. Embrapa Gado de Corte, Rodov. 162, Km 4, Campo Grande, MS 79002-950, Brazil. E-mail: catto@cnpgc.embrapa.br The effect of deworming with ivermectin of cows before calving and of suckling calves on fecal egg counts (EPG) and productive performance of two beef cattle herds in Central Brazil was studied. Four groups of pregnant cows received the following treatments: T1- cows and calves not treated, T2- only calves treated, T3- only cows treated, and T4- cows and calves treated. The calves of T2 and T4 were distributed in the following treatments: A- calves treated at 3 to 5 months of age with long action ivermectin, B- treated with ivermectin, and C- control. For the cows, the deworming did not diminish the EPG during lactation and also did not have significant effect on the conception rate, live weight gain and the body weight of their calves at 3 to 5 months of age. The calves of treatment A gained, from the time of treatment to weaning (84 to 108 days), an average of 4.2kg (P=0.0003) and 7.1kg (P<0.0001) more than those of treatment B and C, respectively. The average difference in live weight gain of 2.9kg between the animals of treatment B and C was not significant. The EPG before treatment was not significantly different from the treatments (P=0.8665); but at weaning, the average EPG of the calves from treatment A was lower than for treatment B (P=0.0004) and C (P<0.0001). There was no significant difference in the mean EPG for the calves from treatment B and C.

Abstract in English:

Riet-Correa G., Terra F.F., Schild A.L., Riet-Correa F. & Barros S.S. 2005. [Experimental poisoning by Tetrapterys multiglandulosa (Malpighiaceae) in sheep.] Intoxicação experimental por Tetrapterys multiglandulosa (Malpighiaceae) em ovinos. Pesquisa Veterinária Brasileira 25(2):91-96. Curso de Medicina Veterinária, Campus de Castanhal, UFPA, Castanhal, PA 68740-080, Brazil. E-mail: griet@ufpa.br Cardiac fibrosis was observed in a calf showing dullness, weakening and respiratory insufficiency in a farm in the state of São Paulo, where cardiac insufficiency, abortion and nervous signs in cattle were associated with the ingestion of Tetrapterys multiglandulosa. The objectives of this paper were to determine the susceptibility of sheep to the intoxication by T. multiglandulosa, to describe the clinical and pathological characteristics of the intoxication, and to evaluate the possibility of using sheep as an experimental species for toxicological studies with this plant. In a previous experiment to determine the toxicity of T. multiglandulosa to be used in sheep, the green plant was given to a steer at the dose of 22g per kg body weight (g/kg/bw), daily, during 9 days. After 9 days the steer showed nervous signs, and on the 12thday was euthanatized. No gross lesions were observed at necropsy. Status spongiosus was observed on the deeper layers of the cerebral cortex and subcortical white matter. Six male sheep were divided in three groups of two sheep each. Group 1 (Sheep 1 and 2) received daily doses of 6 g/kg/bw of the dry plant, during 30 days; Group 2 (Sheep 3 and 4) received daily doses of 3 g/kg/bw, during 60 days; and Group 3 was the control group. Sheep 1 was euthanatized 30 days after the start of the ingestion. Only cardiac arrhythmia was observed clinically, and no lesions were observed at necropsy. Sheep 2, 3 and 4 had also cardiac arrhythmia from day 9, 12 and 18, respectively. From day 52 they started to show depression, reluctance to move and incoordination. Clinical signs got gradually worst and the sheep were euthanatized on days 60, 70 and 80, when clinical signs were marked, and the animals will die at any moment. Hydrothorax, hydropericardium, ascites, nutmeg appearance of the liver and hard whitish myocardium, mainly in the interventricular septum and left ventricle, were observed at necropsy. Histologically, the heart of Sheep 2, 3 and 4 had areas of fibrosis associated with mononuclear cell infiltration. No lesions were found in the heart of Sheep 1. The 4 treated sheep had status spongiosus in different areas of the cerebrum and brain stem, mainly of the deep layers of the cerebral cortex and subcortical white matter. Status spongiosus were also observed in the cerebellar white matter and cervical medulla. In the later the vacuolization was moderate in the white matter and mild in the grey matter. Status spongiosus were mild in Sheep 1 and moderate to severe in Sheep 2, 3 and 4. On electron microscopy it was observed that the status spongiosus is due to an intramyelinic edema. No gross or histologic lesions were observed on the two control sheep, which were euthanized on day 80 after the start of the experiment.

• etrapterys multiglandulosa Malpighiaceae cardiac fibrosis status spongiosus nervous system sheep.

Abstract in Portuguese:

Riet-Correa G., Terra F.F., Schild A.L., Riet-Correa F. & Barros S.S. 2005. [Experimental poisoning by Tetrapterys multiglandulosa (Malpighiaceae) in sheep.] Intoxicação experimental por Tetrapterys multiglandulosa (Malpighiaceae) em ovinos. Pesquisa Veterinária Brasileira 25(2):91-96. Curso de Medicina Veterinária, Campus de Castanhal, UFPA, Castanhal, PA 68740-080, Brazil. E-mail: griet@ufpa.br Cardiac fibrosis was observed in a calf showing dullness, weakening and respiratory insufficiency in a farm in the state of São Paulo, where cardiac insufficiency, abortion and nervous signs in cattle were associated with the ingestion of Tetrapterys multiglandulosa. The objectives of this paper were to determine the susceptibility of sheep to the intoxication by T. multiglandulosa, to describe the clinical and pathological characteristics of the intoxication, and to evaluate the possibility of using sheep as an experimental species for toxicological studies with this plant. In a previous experiment to determine the toxicity of T. multiglandulosa to be used in sheep, the green plant was given to a steer at the dose of 22g per kg body weight (g/kg/bw), daily, during 9 days. After 9 days the steer showed nervous signs, and on the 12thday was euthanatized. No gross lesions were observed at necropsy. Status spongiosus was observed on the deeper layers of the cerebral cortex and subcortical white matter. Six male sheep were divided in three groups of two sheep each. Group 1 (Sheep 1 and 2) received daily doses of 6 g/kg/bw of the dry plant, during 30 days; Group 2 (Sheep 3 and 4) received daily doses of 3 g/kg/bw, during 60 days; and Group 3 was the control group. Sheep 1 was euthanatized 30 days after the start of the ingestion. Only cardiac arrhythmia was observed clinically, and no lesions were observed at necropsy. Sheep 2, 3 and 4 had also cardiac arrhythmia from day 9, 12 and 18, respectively. From day 52 they started to show depression, reluctance to move and incoordination. Clinical signs got gradually worst and the sheep were euthanatized on days 60, 70 and 80, when clinical signs were marked, and the animals will die at any moment. Hydrothorax, hydropericardium, ascites, nutmeg appearance of the liver and hard whitish myocardium, mainly in the interventricular septum and left ventricle, were observed at necropsy. Histologically, the heart of Sheep 2, 3 and 4 had areas of fibrosis associated with mononuclear cell infiltration. No lesions were found in the heart of Sheep 1. The 4 treated sheep had status spongiosus in different areas of the cerebrum and brain stem, mainly of the deep layers of the cerebral cortex and subcortical white matter. Status spongiosus were also observed in the cerebellar white matter and cervical medulla. In the later the vacuolization was moderate in the white matter and mild in the grey matter. Status spongiosus were mild in Sheep 1 and moderate to severe in Sheep 2, 3 and 4. On electron microscopy it was observed that the status spongiosus is due to an intramyelinic edema. No gross or histologic lesions were observed on the two control sheep, which were euthanized on day 80 after the start of the experiment.

Abstract in English:

Simionatto S., Lima-Rosa C.A.V., Rubin L.L. & Canal C.W. 2005. [A nested-PCR protocol for detection of the chicken anemia virus.] Um protocolo de “nested-PCR” para detecção do virus da anemia das galinhas. Pesquisa Veterinária Brasileira 25(2):106-110. Laboratório de Virologia, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: claudio.canal@ufrgs.br This paper reports a nested polymerase chain reaction (nested-PCR) protocol for detection of chicken anemia virus (CAV), the causal agent of infectious chicken anemia. For DNA extraction from clinical samples, a method based on guanidine thiocyanate was found more sensitive and practical than other extraction protocols tested. The pair of primers used in the initial PCR targeted a 664 bp fragment on the VP1 gene. The primers for the internal PCR targeted a fragment of 520 bp. The specificity of the primers was evaluated on samples of CAV controlled flocks. Thirty different viruses and bacteria isolated from chickens did not give rise to any amplification product in the assay. The sensitivity of the nested-PCR was determined on serial dilutions of a CAV vaccine. The nested-PCR was more sensitive than a one step PCR and was able to detect at least 0.16 TCID50 of the vaccine strain. In addition, the protocol employed here detected viral DNA from tissues, sera and litter from flocks with or without clinical signs of disease. It is concluded that the nested-PCR protocol described here is more sensitive, faster and less cumbersome than virus isolation in cell culture as a diagnostic technique for detection of CAV.

• Chicken anemia virus CAV molecular diagnosis nested-PCR.

Abstract in Portuguese:

Simionatto S., Lima-Rosa C.A.V., Rubin L.L. & Canal C.W. 2005. [A nested-PCR protocol for detection of the chicken anemia virus.] Um protocolo de “nested-PCR” para detecção do virus da anemia das galinhas. Pesquisa Veterinária Brasileira 25(2):106-110. Laboratório de Virologia, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: claudio.canal@ufrgs.br This paper reports a nested polymerase chain reaction (nested-PCR) protocol for detection of chicken anemia virus (CAV), the causal agent of infectious chicken anemia. For DNA extraction from clinical samples, a method based on guanidine thiocyanate was found more sensitive and practical than other extraction protocols tested. The pair of primers used in the initial PCR targeted a 664 bp fragment on the VP1 gene. The primers for the internal PCR targeted a fragment of 520 bp. The specificity of the primers was evaluated on samples of CAV controlled flocks. Thirty different viruses and bacteria isolated from chickens did not give rise to any amplification product in the assay. The sensitivity of the nested-PCR was determined on serial dilutions of a CAV vaccine. The nested-PCR was more sensitive than a one step PCR and was able to detect at least 0.16 TCID50 of the vaccine strain. In addition, the protocol employed here detected viral DNA from tissues, sera and litter from flocks with or without clinical signs of disease. It is concluded that the nested-PCR protocol described here is more sensitive, faster and less cumbersome than virus isolation in cell culture as a diagnostic technique for detection of CAV.

Abstract in English:

Rissi D.R., Rech R.R., Fighera R.A., Cagnini D.Q., Kommers G.D. & Barros C.S.L. 2005. [Spontaneous Baccharis coridifolia poisoning in cattle.] Intoxicação espontânea por Baccharis coridifolia em bovinos. Pesquisa Veterinária Brasileira 25(2):111-114. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two outbreaks of Baccharis coridifolia poisoning in cattle in southern Brazil are described. Cases occurred when stressed, hungry and thirsty cattle brought from pastures free of B. coridifolia were placed into pastures heavily infested by this poisonous plant. In the two outbreaks morbidity was 21.73% and 22.51% and lethality was virtually 100%. Clinical signs included mild bloat, instability of hind limbs, muscle tremors, dry muzzle, dry feces or diarrhea, polydipsia and restlessness. Consistent necropsy findings included dehydration, large amounts of ruminal fluid, reddening and erosions of the mucosae of the forestomachs. Degeneration and necrosis of the lining epithelium of the forestomachs and of lymphoid tissue were the main histopathological changes encountered.

• Poisonous plants Baccharis coridifolia Asteraceae diseases of cattle pathology.

Abstract in Portuguese:

Rissi D.R., Rech R.R., Fighera R.A., Cagnini D.Q., Kommers G.D. & Barros C.S.L. 2005. [Spontaneous Baccharis coridifolia poisoning in cattle.] Intoxicação espontânea por Baccharis coridifolia em bovinos. Pesquisa Veterinária Brasileira 25(2):111-114. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two outbreaks of Baccharis coridifolia poisoning in cattle in southern Brazil are described. Cases occurred when stressed, hungry and thirsty cattle brought from pastures free of B. coridifolia were placed into pastures heavily infested by this poisonous plant. In the two outbreaks morbidity was 21.73% and 22.51% and lethality was virtually 100%. Clinical signs included mild bloat, instability of hind limbs, muscle tremors, dry muzzle, dry feces or diarrhea, polydipsia and restlessness. Consistent necropsy findings included dehydration, large amounts of ruminal fluid, reddening and erosions of the mucosae of the forestomachs. Degeneration and necrosis of the lining epithelium of the forestomachs and of lymphoid tissue were the main histopathological changes encountered.

Abstract in English:

Simionatto S., Vaz E.K., Michelon A., Seixas F.K., Dellagostin O.A. 2005. [Development and evaluation of new strategies for immunization against swine colibacillosis.] Desenvolvimento e avaliação de novas estratégias de imunização contra colibacilose suína. Pes-quisa Veterinária Brasileira 25(2):84-90. Laboratório de Biologia Molecular, Centro de Bio-tecnologia, UFPel, Campus Capão do Leão, Cx. Postal 354, Pelotas, RS 96010-900, Brazil. E-mail: ssimionatto@bol.com.br Swine colibacillosis caused by enterotoxigenic Escherichia coli remains one of the main sanitary problems in pig farms. The recombinant DNA technology offers the possibility of developing new immunization strategies. This paper describes the development of a subunit vaccine through the expression and purification of the E. coli K88 FaeC fimbrial protein. The gene that codes for this antigen was amplified by PCR and cloned into an E. coli expression vector fused to a 6X histidine tag. The recombinant protein was purified by affinity chromatography and used for mice immunization. In parallel, the same gene was cloned into an eucariotic expression vector with the addition of the Kozak sequence for improving translation of this gene in muscle cells. The resulting plasmid named pUP310 was purified in large scale and used to immunize mice. The immune response afforded by both forms of immunization was monitored by ELISA. There was an immune response in mice inoculated with pUP310 and purified FaeC. It was possible to detect anti-FaeC antibodies 42 days after the first inoculation. The antibody titer increased with time, being still detectable 7 months after the first inoculation. It is concluded that recombinant FaeC and pUP310 are potential tools for immunization of swine against E. coli K88.

• Swine colibacillosis FaeC Escherichia coli DNA vaccine recombinant vaccine.

Abstract in Portuguese:

Simionatto S., Vaz E.K., Michelon A., Seixas F.K., Dellagostin O.A. 2005. [Development and evaluation of new strategies for immunization against swine colibacillosis.] Desenvolvimento e avaliação de novas estratégias de imunização contra colibacilose suína. Pes-quisa Veterinária Brasileira 25(2):84-90. Laboratório de Biologia Molecular, Centro de Bio-tecnologia, UFPel, Campus Capão do Leão, Cx. Postal 354, Pelotas, RS 96010-900, Brazil. E-mail: ssimionatto@bol.com.br Swine colibacillosis caused by enterotoxigenic Escherichia coli remains one of the main sanitary problems in pig farms. The recombinant DNA technology offers the possibility of developing new immunization strategies. This paper describes the development of a subunit vaccine through the expression and purification of the E. coli K88 FaeC fimbrial protein. The gene that codes for this antigen was amplified by PCR and cloned into an E. coli expression vector fused to a 6X histidine tag. The recombinant protein was purified by affinity chromatography and used for mice immunization. In parallel, the same gene was cloned into an eucariotic expression vector with the addition of the Kozak sequence for improving translation of this gene in muscle cells. The resulting plasmid named pUP310 was purified in large scale and used to immunize mice. The immune response afforded by both forms of immunization was monitored by ELISA. There was an immune response in mice inoculated with pUP310 and purified FaeC. It was possible to detect anti-FaeC antibodies 42 days after the first inoculation. The antibody titer increased with time, being still detectable 7 months after the first inoculation. It is concluded that recombinant FaeC and pUP310 are potential tools for immunization of swine against E. coli K88.

Abstract in English:

Seitz A.L., Colodel E.M., Barros S.S. & Driemeier D. 2005. [Experimental poisoning by Sida carpinifolia (Malvaceae) in sheep.] Intoxicação experimental por Sida carpinifolia (Malvaceae) em ovinos. Pesquisa Veterinária Brasileira 25(1):15-20. Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 91540-000, Brazil. E-mail: alseitz@terra.com.br. Seven sheep received dry crushed Sida carpinifolia L.f. One of them died at 18 and other at 53 days of the experiment. Four others were euthanatized and necropsied at 30, 45, 75 and 100 days. For one sheep the supply of S. carpinifolia was interrupted on the 80th day of the experiment, and 70 days later the animal was euthanized and necropsied. The minimal amount of the dry plant consumed was 11 g/kg and the maximum was 30 g/kg. The progression of clinical findings was similar in six animals with slight diarrhea at 20 days of experiment. Neurological signs were observed at 25 days and included ataxia with dysmetria, muscle tremors of the head, atypical postural reactions, frequent falls, sluggish of movements, difficulty in grazing and swallowing. These signs were enhanced when the animals were forced to walk. Four of the animals presented progressive emaciation. The sheep whose supply of the plant was interrupted recovered gradually, and 11 days after the animal returned to normal. During necropsy, only enlarged mesenteric lymph nodes were observed. The histological alterations were more significant in the central nervous system, with multiple and severe cytoplasmic distention and vacuolation which affects specially Purkinje cells of the cerebellum, neurons of cerebral cortex, thalamus, midbrain and the ventral horn of spinal cord. Axonal spheroids in the brain, more frequently in the granular layer of cerebellum were also observed. The cytoplasmic vacuolation was also found in pancreatic acinar cells, renal tubules, thyroid follicular epithelium, hepatocytes and macrophages of lymphoid organs. The ultrastructural lesions observed were cytoplasmic vacuolation, some surrounded by membranes in Purkinje cells of cerebellum and thyroid follicular cells. The sheep, which had S. carpinifolia withdrawn from its diet for 70 days, had no significant histological alterations.

• Toxic plants plant poisoning Sida carpinifolia Malvaceae lysosomal storage disease swainsonine electronic microscopy.

Abstract in Portuguese:

Seitz A.L., Colodel E.M., Barros S.S. & Driemeier D. 2005. [Experimental poisoning by Sida carpinifolia (Malvaceae) in sheep.] Intoxicação experimental por Sida carpinifolia (Malvaceae) em ovinos. Pesquisa Veterinária Brasileira 25(1):15-20. Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 91540-000, Brazil. E-mail: alseitz@terra.com.br. Seven sheep received dry crushed Sida carpinifolia L.f. One of them died at 18 and other at 53 days of the experiment. Four others were euthanatized and necropsied at 30, 45, 75 and 100 days. For one sheep the supply of S. carpinifolia was interrupted on the 80th day of the experiment, and 70 days later the animal was euthanized and necropsied. The minimal amount of the dry plant consumed was 11 g/kg and the maximum was 30 g/kg. The progression of clinical findings was similar in six animals with slight diarrhea at 20 days of experiment. Neurological signs were observed at 25 days and included ataxia with dysmetria, muscle tremors of the head, atypical postural reactions, frequent falls, sluggish of movements, difficulty in grazing and swallowing. These signs were enhanced when the animals were forced to walk. Four of the animals presented progressive emaciation. The sheep whose supply of the plant was interrupted recovered gradually, and 11 days after the animal returned to normal. During necropsy, only enlarged mesenteric lymph nodes were observed. The histological alterations were more significant in the central nervous system, with multiple and severe cytoplasmic distention and vacuolation which affects specially Purkinje cells of the cerebellum, neurons of cerebral cortex, thalamus, midbrain and the ventral horn of spinal cord. Axonal spheroids in the brain, more frequently in the granular layer of cerebellum were also observed. The cytoplasmic vacuolation was also found in pancreatic acinar cells, renal tubules, thyroid follicular epithelium, hepatocytes and macrophages of lymphoid organs. The ultrastructural lesions observed were cytoplasmic vacuolation, some surrounded by membranes in Purkinje cells of cerebellum and thyroid follicular cells. The sheep, which had S. carpinifolia withdrawn from its diet for 70 days, had no significant histological alterations.

Abstract in English:

D'Ávila da Silva A., Sortica V.A., Braga A.C., Spilki F.R., Franco A.C., Esteves P.A., Rijsewijk F., Rosa J.C.A., Batista H.B.C.R., Oliveira A.P. & Roehe P.M. 2005. [Antigenic and molecular characterization of eight samples of Aujeszky’s disease virus isolated in the state of Rio Grande do Sul, Brazil, in 2003.] Caracterização antigênica e molecular de oito amostras do virus da doença de Aujeszky isoladas no estado do Rio Grande do Sul em 2003. Pesquisa Veterinária Brasileira 25(1):21-24. Instituto de Pesquisas Veterinárias Desidério Finamor (IPVDF), Fepagro Saúde Animal, Estrada do Conde 6000, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@ufrgs.br Pseudorabies or Aujeszky’s disease (AD), caused by pseudorabies virus (PRV) is a major concern in swine production. In the state of Rio Grande do Sul, Brazil, AD was only detected in 1954, in cattle. In 2003 two outbreaks of encephalitis occurred on the northern region of the state, close to the border with the state of Santa Catarina. Pseudorabies virus (PRV) was isolated from distinct farms within the region and subjected to antigenic and genomic analyses. These isolates were compared with prototype strains NIA-3 and NP. Antigenic characterization with a panel of monoclonal antibodies (Mabs) directed to viral glycoproteins (gB, gC, gD and gE,) was performed by an imunoperoxidase monolayer assay (IPMA) on infected cell monolayers. Genomic characterization was carried out by restriction enzyme analysis (REA) of the whole DNA viral genome with Bam HI. The antigenic profile of the eight isolates from Rio Grande do Sul as well as strains NIA-3 and NP were similar. REA analysis revealed that all isolates from Rio Grande do Sul displayed a genomic type II arrangement, a genotype often found in other outbreaks of AD previously reported in other Brazilian states. The results obtained suggest that the eight isolates examined here were similar.

• Aujeszky's disease epidemiology.

Abstract in Portuguese:

D'Ávila da Silva A., Sortica V.A., Braga A.C., Spilki F.R., Franco A.C., Esteves P.A., Rijsewijk F., Rosa J.C.A., Batista H.B.C.R., Oliveira A.P. & Roehe P.M. 2005. [Antigenic and molecular characterization of eight samples of Aujeszky’s disease virus isolated in the state of Rio Grande do Sul, Brazil, in 2003.] Caracterização antigênica e molecular de oito amostras do virus da doença de Aujeszky isoladas no estado do Rio Grande do Sul em 2003. Pesquisa Veterinária Brasileira 25(1):21-24. Instituto de Pesquisas Veterinárias Desidério Finamor (IPVDF), Fepagro Saúde Animal, Estrada do Conde 6000, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@ufrgs.br Pseudorabies or Aujeszky’s disease (AD), caused by pseudorabies virus (PRV) is a major concern in swine production. In the state of Rio Grande do Sul, Brazil, AD was only detected in 1954, in cattle. In 2003 two outbreaks of encephalitis occurred on the northern region of the state, close to the border with the state of Santa Catarina. Pseudorabies virus (PRV) was isolated from distinct farms within the region and subjected to antigenic and genomic analyses. These isolates were compared with prototype strains NIA-3 and NP. Antigenic characterization with a panel of monoclonal antibodies (Mabs) directed to viral glycoproteins (gB, gC, gD and gE,) was performed by an imunoperoxidase monolayer assay (IPMA) on infected cell monolayers. Genomic characterization was carried out by restriction enzyme analysis (REA) of the whole DNA viral genome with Bam HI. The antigenic profile of the eight isolates from Rio Grande do Sul as well as strains NIA-3 and NP were similar. REA analysis revealed that all isolates from Rio Grande do Sul displayed a genomic type II arrangement, a genotype often found in other outbreaks of AD previously reported in other Brazilian states. The results obtained suggest that the eight isolates examined here were similar.

Abstract in English:

Amaral L.A, Isa H., Dias L.T., Rossi Jr. O.D. & Nader Filho A. 2004. [Efficiency of the disinfection of teatcups and teats during mechanic milking of dairy cows.] Avaliação da eficiência da desinfecção de teteiras e dos tetos no processo de ordenha mecânica de vacas. Pesquisa Veterinária Brasileira 24(4):173-177. FCAV, Universidade Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP 14884-900, Brazil. E-mail: lamaral@fcav.unesp.br The purpose of this investigation was to evaluate the efficiency of the teatcup disinfection process by immersion into a disinfectant solution, using sodium hypochlorite and organic chlorine, to verify the residual chlorine dynamics in both solutions during milking time, and to evaluate three premilking disinfection methods: immersion, spray and sponge. Total coliforms, fecal coliforms, Staphylococcus sp and mesophilic microorganism counting was done. The results showed that the disinfecting clusters between individual cows, using immersion in sodium hypochlorite or organic chlorine solutions with a concentration of 150ppm, was not efficient for the rubber teatcup microorganism reduction. The organic chlorine solution showed more stability. Teatcup is a potential microorganism vehicle for milk and the mammary gland. Disinfection of the teats reduced the number of the microorganisms studied in all treatments, showing to be a simple method that can be used to reduce the microrganism transmission risks during milking and to increase the microbial quality of the milk.

• Disinfection milking chlorine teatcups pre-dipping.

Abstract in Portuguese:

Amaral L.A, Isa H., Dias L.T., Rossi Jr. O.D. & Nader Filho A. 2004. [Efficiency of the disinfection of teatcups and teats during mechanic milking of dairy cows.] Avaliação da eficiência da desinfecção de teteiras e dos tetos no processo de ordenha mecânica de vacas. Pesquisa Veterinária Brasileira 24(4):173-177. FCAV, Universidade Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP 14884-900, Brazil. E-mail: lamaral@fcav.unesp.br The purpose of this investigation was to evaluate the efficiency of the teatcup disinfection process by immersion into a disinfectant solution, using sodium hypochlorite and organic chlorine, to verify the residual chlorine dynamics in both solutions during milking time, and to evaluate three premilking disinfection methods: immersion, spray and sponge. Total coliforms, fecal coliforms, Staphylococcus sp and mesophilic microorganism counting was done. The results showed that the disinfecting clusters between individual cows, using immersion in sodium hypochlorite or organic chlorine solutions with a concentration of 150ppm, was not efficient for the rubber teatcup microorganism reduction. The organic chlorine solution showed more stability. Teatcup is a potential microorganism vehicle for milk and the mammary gland. Disinfection of the teats reduced the number of the microorganisms studied in all treatments, showing to be a simple method that can be used to reduce the microrganism transmission risks during milking and to increase the microbial quality of the milk.