PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Penatti M.P.A., Silva A.S., Valadares G.F. & Leite D.S. 2005. Occurrence of F42 colonization factor in Escherichia coli strains isolated from piglets with diarrhea. Pesquisa Veterinária Brasileira 25(1):31-33. Depto Microbiologia e Imunologia, Instituto de Biologia, Unicamp, Campinas, SP 13081-970, Brazil. E-mail: domingos@unicamp.br The objective of this study was to determine the presence of the colonization factor F42 in 168 strains of Escherichia coli isolated from diarrheic stools of newborn piglets. The presence of F42 in 12 (7.1%) strains was detected with the agglutination test. Through the Polymerase Chain Reaction (PCR) of F42 positive strains, gene encoding enterotoxins (ST-I, ST-II, LT-I and LT-II) were detected. The finding of ST-I/ST-II genes in 50% of the strains, ST-I (16%) and ST-II (25%) indicates a strong association of FC F42 with heat-stable enterotoxins (91%). In contrast, the thermolabile enterotoxin (LT-I and LT-II) genes were not detected. Serogroups of F42 positive strains were determined, serogroup O8 being the most prevalent (41,7%). Other serogroups, as there are O9, O11, O18, O32, O35, O98 and O101, were also identified. Thus, FC F42 was confirmed as an additional factor of virulence in the pathogenesis of porcine colibacillosis.

• Escherichia coli F42 piglets fimbriae diarrhea PCR.

Abstract in Portuguese:

Penatti M.P.A., Silva A.S., Valadares G.F. & Leite D.S. 2005. Occurrence of F42 colonization factor in Escherichia coli strains isolated from piglets with diarrhea. Pesquisa Veterinária Brasileira 25(1):31-33. Depto Microbiologia e Imunologia, Instituto de Biologia, Unicamp, Campinas, SP 13081-970, Brazil. E-mail: domingos@unicamp.br The objective of this study was to determine the presence of the colonization factor F42 in 168 strains of Escherichia coli isolated from diarrheic stools of newborn piglets. The presence of F42 in 12 (7.1%) strains was detected with the agglutination test. Through the Polymerase Chain Reaction (PCR) of F42 positive strains, gene encoding enterotoxins (ST-I, ST-II, LT-I and LT-II) were detected. The finding of ST-I/ST-II genes in 50% of the strains, ST-I (16%) and ST-II (25%) indicates a strong association of FC F42 with heat-stable enterotoxins (91%). In contrast, the thermolabile enterotoxin (LT-I and LT-II) genes were not detected. Serogroups of F42 positive strains were determined, serogroup O8 being the most prevalent (41,7%). Other serogroups, as there are O9, O11, O18, O32, O35, O98 and O101, were also identified. Thus, FC F42 was confirmed as an additional factor of virulence in the pathogenesis of porcine colibacillosis.

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:

França T.N., Peixoto P.V., Brito M.F., Driemeier D., Mores N. & Zanella J. 2005. [Outbreak of Circovirosis (Porcine Postweaning Multisystemic Wasting Syndrome) in the state of Rio de Janeiro, Brazil.] Surto de Circovirose (Síndrome Definhante Multissistêmica de Suínos Desmamados) no estado do Rio de Janeiro. Pesquisa Veterinária Brasileira 25(1):39-53. Universidade Estácio de Sá, Curso de Medicina Veterinária, Disciplina de Anatomia Patológica, Estrada Boca do Mato 850, Vargem Pequena, RJ 22783-320, Brazil. E-mail: ticianaf@uol.com.br The first outbreak of Postweaning Multisystemic Wasting Syndrome (PMWS) in swine, which occurred in southeastern Brazil, in the state of Rio de Janeiro, is described. The disease, which affects mainly weaned about 4 month-old pigs, caused the death of at least 14 animals. The property, where the outbreak occurred, had inadequate sanitary and management conditions. Clinically the disease was characterized by wasting, poor development, cough, tachypnoea, dispnoea, diarrhoea, ataxia, tremors after stimulation, decubitus and convulsions. The course of the disease was acute or subacute. The most important post-mortem findings were enlarged lymphnodes, non-collapsed lungs, with consolidated areas mainly in the cranial lobes. Histological lesions consisted mainly of lymphohistiocytic infiltration with multinucleate giant cells in lymph nodes, spleen, Peyer’s patches, kidney, lung and liver, depletion or lymphoid hyperplasia, as well as lymphohistiocytic interstitial pneumonia and areas of secondary bronchopneumonia. The diagnosis was established through observations of the symptoms and typical lesions, and was confirmed by immunohistochemical examination and PCR. The objective of this study was to characterize the epidemiological, clinical and pathological aspects of the outbreak of PMWS, because of the severe direct or indirect economical losses caused by the disease to the world pig industry.

• Postweaning multisystemic wasting syndrome porcine circovirus type 2 pathology immunohistochemistry PCR.

Abstract in Portuguese:

França T.N., Peixoto P.V., Brito M.F., Driemeier D., Mores N. & Zanella J. 2005. [Outbreak of Circovirosis (Porcine Postweaning Multisystemic Wasting Syndrome) in the state of Rio de Janeiro, Brazil.] Surto de Circovirose (Síndrome Definhante Multissistêmica de Suínos Desmamados) no estado do Rio de Janeiro. Pesquisa Veterinária Brasileira 25(1):39-53. Universidade Estácio de Sá, Curso de Medicina Veterinária, Disciplina de Anatomia Patológica, Estrada Boca do Mato 850, Vargem Pequena, RJ 22783-320, Brazil. E-mail: ticianaf@uol.com.br The first outbreak of Postweaning Multisystemic Wasting Syndrome (PMWS) in swine, which occurred in southeastern Brazil, in the state of Rio de Janeiro, is described. The disease, which affects mainly weaned about 4 month-old pigs, caused the death of at least 14 animals. The property, where the outbreak occurred, had inadequate sanitary and management conditions. Clinically the disease was characterized by wasting, poor development, cough, tachypnoea, dispnoea, diarrhoea, ataxia, tremors after stimulation, decubitus and convulsions. The course of the disease was acute or subacute. The most important post-mortem findings were enlarged lymphnodes, non-collapsed lungs, with consolidated areas mainly in the cranial lobes. Histological lesions consisted mainly of lymphohistiocytic infiltration with multinucleate giant cells in lymph nodes, spleen, Peyer’s patches, kidney, lung and liver, depletion or lymphoid hyperplasia, as well as lymphohistiocytic interstitial pneumonia and areas of secondary bronchopneumonia. The diagnosis was established through observations of the symptoms and typical lesions, and was confirmed by immunohistochemical examination and PCR. The objective of this study was to characterize the epidemiological, clinical and pathological aspects of the outbreak of PMWS, because of the severe direct or indirect economical losses caused by the disease to the world pig industry.

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:

Groff F.H.S., Merlo M.A., Stoll P.A., Stepan A.L., Weiblen R. & Flores E.F. 2005. [Epidemiology and control of pseudorabies outbreaks in the state of Rio Grande do Sul, Brazil, 2003.] Epidemiologia e controle dos focos da doença de Aujeszky no Rio Grande do Sul, em 2003. Pesquisa Veterinária Brasileira 25(1):25-30. Depto Medicina Veterinária Preventiva, Universi-dade Federal de Santa Maria (UFSM), Santa Maria, RS 97105-900, Brazil. E-mail: flores@ccr.ufsm.br Aujeszky’s disease (AD) or pseudorabies is an important viral disease of swine and has significant economic impact on the pig industry worldwide. The infection produces direct and indirect economic losses, mainly due to restrictions to international trade of swine products. Since the beginning of the 20th century, AD had been notified in several Brazilian regions, yet the state of Rio Grande do Sul (RS) remained as a “provisionally free” area under the International Organization of Epizooties (OIE) guidelines. In 2003, two outbreaks were notified in swine herds located in northern RS, boundary with Santa Catarina, a state where the infection is endemic. Control/eradication measures consisted in tracing back all swine movements, quarantine and eradication of the affected herds by sanitary slaughter under official inspection. In outbreak # 1 (Pinheirinho do Vale, January/2003) six herds were affected, one of which presented animals with clinical signs. Starting from this outbreak, 146 herds and 42.399 pigs were traced back, six herds (7.822 animals) being depopulated – the herd where the index outbreak plus five other herds with positive serology. The outbreak # 2 (Aratiba, September/2003) resulted in a wider spread of the infection, involving another three counties and 77 herds (9 with clinical signs, 68 with positive serology). From the index case, 109.316 pigs in 630 herds were traced back; 28.443 animals from positive herds were slaughtered. Total numbers reached 151.715 traced back animals in 776 herds; 71 herds were found serologically positive. The adopted measures were efficient to eliminate the outbreaks and to stop the disease spread to neighboring areas, reestablishing the sanitary status previous to the outbreaks.

• Aujeszky’s disease pseudorabies ADV PRV epidemiology.

Abstract in Portuguese:

Groff F.H.S., Merlo M.A., Stoll P.A., Stepan A.L., Weiblen R. & Flores E.F. 2005. [Epidemiology and control of pseudorabies outbreaks in the state of Rio Grande do Sul, Brazil, 2003.] Epidemiologia e controle dos focos da doença de Aujeszky no Rio Grande do Sul, em 2003. Pesquisa Veterinária Brasileira 25(1):25-30. Depto Medicina Veterinária Preventiva, Universi-dade Federal de Santa Maria (UFSM), Santa Maria, RS 97105-900, Brazil. E-mail: flores@ccr.ufsm.br Aujeszky’s disease (AD) or pseudorabies is an important viral disease of swine and has significant economic impact on the pig industry worldwide. The infection produces direct and indirect economic losses, mainly due to restrictions to international trade of swine products. Since the beginning of the 20th century, AD had been notified in several Brazilian regions, yet the state of Rio Grande do Sul (RS) remained as a “provisionally free” area under the International Organization of Epizooties (OIE) guidelines. In 2003, two outbreaks were notified in swine herds located in northern RS, boundary with Santa Catarina, a state where the infection is endemic. Control/eradication measures consisted in tracing back all swine movements, quarantine and eradication of the affected herds by sanitary slaughter under official inspection. In outbreak # 1 (Pinheirinho do Vale, January/2003) six herds were affected, one of which presented animals with clinical signs. Starting from this outbreak, 146 herds and 42.399 pigs were traced back, six herds (7.822 animals) being depopulated – the herd where the index outbreak plus five other herds with positive serology. The outbreak # 2 (Aratiba, September/2003) resulted in a wider spread of the infection, involving another three counties and 77 herds (9 with clinical signs, 68 with positive serology). From the index case, 109.316 pigs in 630 herds were traced back; 28.443 animals from positive herds were slaughtered. Total numbers reached 151.715 traced back animals in 776 herds; 71 herds were found serologically positive. The adopted measures were efficient to eliminate the outbreaks and to stop the disease spread to neighboring areas, reestablishing the sanitary status previous to the outbreaks.

Abstract in English:

Traverso S.D., Correa A.M.R., Schmitz M., Colodel E.M. & Driemeier D. 2004 [Experimental poisoning by Trema micrantha (Ulmaceae) in cattle.] Intoxicação experi-mental por Trema micrantha (Ulmaceae) em bovinos. Pesquisa Veterinária Brasileira 24(4):211-216. Setor de Patologia Veterinária, Depto Patologia Clínica Veterinária, Faculdade de Veteriná-ria, UFRGS, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@vortex.ufrgs.br Leaves of Trema micrantha were orally given to 13 cattle. Ten animals received green leaves in a single dose, two animals received green leaves in fractionated doses, and one received the dried leaves in a single dose. Eight animals showed clinical signs and six of them died. Clinical signs were observed 16 hours after administration and included apathy, anorexia, drooling, progressive weakness, coma and death. Neurological signs as pressing the head against obstacles and head shaking were observed in four animals . Death occurred between 67 and 153 hours after the end of plant ingestion. The main gross lesions were observed in the liver, and included friable consistency, pronounced lobular pattern and areas of haemorrhages. The liver of one bovine was homogeneously dark reddened. Petechial hemorrhages in serosal membranes and edema in the gall bladder were frequently seen. Pale kidneys with red spots in the cortex were observed in one animal. Microscopically, the most striking lesion in the liver was massive coagulative necrosis, associated with centrolobular haemorrhages, observed in four animals. In the liver of one bovine centrolobular necrosis was observed . Tubular renal necrosis was noted in two animals. Additional microscopic lesions were found in the central nervous system of five bovines, especially in the frontal cortex, and included perineuronal and perivascular edema with basophilia and retraction of the neurons. T T. micrantha caused clinical signs with 50g/kg and death with doses of 54g/kg or higher. The fractionated administration of the green leaves as well as the dried leaves did not cause poisoning.

• Poisonous plants plant poisoning Trema micrantha Ulmaceae cattle liver necrosis.

Abstract in Portuguese:

Traverso S.D., Correa A.M.R., Schmitz M., Colodel E.M. & Driemeier D. 2004 [Experimental poisoning by Trema micrantha (Ulmaceae) in cattle.] Intoxicação experi-mental por Trema micrantha (Ulmaceae) em bovinos. Pesquisa Veterinária Brasileira 24(4):211-216. Setor de Patologia Veterinária, Depto Patologia Clínica Veterinária, Faculdade de Veteriná-ria, UFRGS, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@vortex.ufrgs.br Leaves of Trema micrantha were orally given to 13 cattle. Ten animals received green leaves in a single dose, two animals received green leaves in fractionated doses, and one received the dried leaves in a single dose. Eight animals showed clinical signs and six of them died. Clinical signs were observed 16 hours after administration and included apathy, anorexia, drooling, progressive weakness, coma and death. Neurological signs as pressing the head against obstacles and head shaking were observed in four animals . Death occurred between 67 and 153 hours after the end of plant ingestion. The main gross lesions were observed in the liver, and included friable consistency, pronounced lobular pattern and areas of haemorrhages. The liver of one bovine was homogeneously dark reddened. Petechial hemorrhages in serosal membranes and edema in the gall bladder were frequently seen. Pale kidneys with red spots in the cortex were observed in one animal. Microscopically, the most striking lesion in the liver was massive coagulative necrosis, associated with centrolobular haemorrhages, observed in four animals. In the liver of one bovine centrolobular necrosis was observed . Tubular renal necrosis was noted in two animals. Additional microscopic lesions were found in the central nervous system of five bovines, especially in the frontal cortex, and included perineuronal and perivascular edema with basophilia and retraction of the neurons. T T. micrantha caused clinical signs with 50g/kg and death with doses of 54g/kg or higher. The fractionated administration of the green leaves as well as the dried leaves did not cause poisoning.

Abstract in English:

Lima M., Flores E.F., Weiblen R., Flores F.S.F. & Arenhart S. 2004. [Characterization of bovine viral diarrhea virus (BVDV) types 1 and 2 isolates for use in vaccines.] Caracterização de amostras atenuadas do vírus da Diarréia Viral Bovina (BVDV) tipos 1 e 2 para uso em vacinas. Pesquisa Veterinária Brasileira 24(1):35-42. Depto Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Santa Maria, RS 97105-900, Brazil. E-mail: flores@ccr.ufsm.br This article reports the characterization of two cytopathic isolates of bovine viral diarrhea virus (BVDV-1: IBSP-2; BVDV-2:SV-253) submitted to multiple passages (n=30) in tissue culture associated with ultraviolet irradiation. The vaccine candidate strains were characterized in vitro (plaque size and morphology, growth kinetics and antigenic profile) and in vivo (attenuation and serological response in calves). In vitro characterization of biologically cloned viruses obtained at passages 0, 1, 10, 20 and 30 demonstrated that the attenuation process did not significantly affect the phenotypic and antigenic properties of the viruses. No major differences in plaque size and morphology and in the growth kinetics in tissue culture were observed among the viruses obtained at different passages. Likewise, the antigenic profile of these viruses did not change upon successive passages in tissue culture, as ascertained by the pattern of binding by 48 monoclonal antibodies (mAbs). Intramuscular inoculation of both viruses (IBSP-2: 107.3 TCID50; SV-253: 106.8 TCID50) at passage 30 (p30) in twelve 15 months old heifers did not produce clinical signs, demonstrating the attenuation of the viruses. Following inoculation, infectious virus was detected in leucocytes of most inoculated animals (10/12) between days 3 and 6 post-inoculation (pi) and in nasal secretions of three animals (days 4, 7 and 8pi). However, the vaccine viruses were not transmitted to three seronegative calves maintained as sentinels. All vaccinated calves seroconverted at day 14 post-vaccination. A moderate to high serum neutralizing response against five Brazilian BVDV-1 (titers from 80 to ³1,280) and four Brazilian BVDV-2 isolates (titers from 20 to 640) was observed at day 33 post-vaccination (pv). In general, the highest titers were observed against the Brazilian BVDV-1 isolates. At day 240 post-vaccination, the animals received a booster administration (IBSP-2: 107.3 TCID50 and SV-253: 106.8 TCID50). Revaccination resulted in a strong anamnestic response in most animals, with increasing antibody titers mainly to BVDV-2. These are promising results towards the future use of these strains in modified-live vaccines for the control of BVDV infection in Brazil.

• Bovine viral diarrhea virus (BVDV) modified-live vaccine attenuation.

Abstract in Portuguese:

Lima M., Flores E.F., Weiblen R., Flores F.S.F. & Arenhart S. 2004. [Characterization of bovine viral diarrhea virus (BVDV) types 1 and 2 isolates for use in vaccines.] Caracterização de amostras atenuadas do vírus da Diarréia Viral Bovina (BVDV) tipos 1 e 2 para uso em vacinas. Pesquisa Veterinária Brasileira 24(1):35-42. Depto Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Santa Maria, RS 97105-900, Brazil. E-mail: flores@ccr.ufsm.br This article reports the characterization of two cytopathic isolates of bovine viral diarrhea virus (BVDV-1: IBSP-2; BVDV-2:SV-253) submitted to multiple passages (n=30) in tissue culture associated with ultraviolet irradiation. The vaccine candidate strains were characterized in vitro (plaque size and morphology, growth kinetics and antigenic profile) and in vivo (attenuation and serological response in calves). In vitro characterization of biologically cloned viruses obtained at passages 0, 1, 10, 20 and 30 demonstrated that the attenuation process did not significantly affect the phenotypic and antigenic properties of the viruses. No major differences in plaque size and morphology and in the growth kinetics in tissue culture were observed among the viruses obtained at different passages. Likewise, the antigenic profile of these viruses did not change upon successive passages in tissue culture, as ascertained by the pattern of binding by 48 monoclonal antibodies (mAbs). Intramuscular inoculation of both viruses (IBSP-2: 107.3 TCID50; SV-253: 106.8 TCID50) at passage 30 (p30) in twelve 15 months old heifers did not produce clinical signs, demonstrating the attenuation of the viruses. Following inoculation, infectious virus was detected in leucocytes of most inoculated animals (10/12) between days 3 and 6 post-inoculation (pi) and in nasal secretions of three animals (days 4, 7 and 8pi). However, the vaccine viruses were not transmitted to three seronegative calves maintained as sentinels. All vaccinated calves seroconverted at day 14 post-vaccination. A moderate to high serum neutralizing response against five Brazilian BVDV-1 (titers from 80 to ³1,280) and four Brazilian BVDV-2 isolates (titers from 20 to 640) was observed at day 33 post-vaccination (pv). In general, the highest titers were observed against the Brazilian BVDV-1 isolates. At day 240 post-vaccination, the animals received a booster administration (IBSP-2: 107.3 TCID50 and SV-253: 106.8 TCID50). Revaccination resulted in a strong anamnestic response in most animals, with increasing antibody titers mainly to BVDV-2. These are promising results towards the future use of these strains in modified-live vaccines for the control of BVDV infection in Brazil.

Abstract in English:

Spilki F.R, Esteves P.A., Lima M., Franco A.C., Chiminazzo C., Flores E.F., Weiblen R., Driemeier D. & Roehe P.M. 2004. Comparative pathogenicity of bovine herpesviruses type 1 (BHV-1) subtypes 1 (BHV-1.1) and 2a (BHV-1.2a). Pesquisa Veterinária Brasileira 24(1):43-49. Centro de Pesquisas Desidério Finamor, Fepagro Saúde Animal, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@ufrgs.br The study aimed to examine the capacity of two bovine herpesvirus type 1 (BHV-1) isolates of different subtypes (EVI 123/96, BHV-1.1; SV265/98, BHV-1.2a) to induce respiratory disease in calves. These two isolates are representative of the BHV-1 subtypes prevalent in Brazil. Viral subtypes were confirmed by monoclonal antibody analysis and by restriction enzyme digestion of viral genomes. The viruses were inoculated intranasally into seven 3 months old calves (four with BHV-1.1, three with BHV-1.2a). Three other calves of identical age and condition were kept as uninfected controls. In both groups of infected calves, the clinical signs observed were consistent with typical infectious bovine rhinothracheitis (IBR), including pyrexia, apathy, anorexia, nasal and ocular mucopurulent discharges, erosions on the nasal mucosa, conjunctivitis, lachrymation, redness of nasal mucosa, dyspnoea, coughing, tracheal stridor and enlargement of retropharingeal, submandibular and cervical lymphnodes. No significant differences were observed between the clinical scores attributed to both groups. Virus shedding in nasal and ocular secretions were also similar, apart from a significant difference in nasal virus shedding on day 1 to 3 post-inoculation, which was higher for BHV-1.1 than for BHV-1.2a. Following corticosteroid induced reactivation of the latent infection, recrudescence of clinical signs was also observed, with no significant differences on both groups. It was concluded that both subtypes BHV-1.1 and BHV-1.2a were able to induce clinically undistinguishable respiratory disease in calves, either subsequent to a primary infection or following reactivation.

• Infectious bovine rhinotracheitis IBR BHV-1.1 BHV-1.2a subtypes pathogenicity.

Abstract in Portuguese:

Spilki F.R, Esteves P.A., Lima M., Franco A.C., Chiminazzo C., Flores E.F., Weiblen R., Driemeier D. & Roehe P.M. 2004. Comparative pathogenicity of bovine herpesviruses type 1 (BHV-1) subtypes 1 (BHV-1.1) and 2a (BHV-1.2a). Pesquisa Veterinária Brasileira 24(1):43-49. Centro de Pesquisas Desidério Finamor, Fepagro Saúde Animal, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@ufrgs.br The study aimed to examine the capacity of two bovine herpesvirus type 1 (BHV-1) isolates of different subtypes (EVI 123/96, BHV-1.1; SV265/98, BHV-1.2a) to induce respiratory disease in calves. These two isolates are representative of the BHV-1 subtypes prevalent in Brazil. Viral subtypes were confirmed by monoclonal antibody analysis and by restriction enzyme digestion of viral genomes. The viruses were inoculated intranasally into seven 3 months old calves (four with BHV-1.1, three with BHV-1.2a). Three other calves of identical age and condition were kept as uninfected controls. In both groups of infected calves, the clinical signs observed were consistent with typical infectious bovine rhinothracheitis (IBR), including pyrexia, apathy, anorexia, nasal and ocular mucopurulent discharges, erosions on the nasal mucosa, conjunctivitis, lachrymation, redness of nasal mucosa, dyspnoea, coughing, tracheal stridor and enlargement of retropharingeal, submandibular and cervical lymphnodes. No significant differences were observed between the clinical scores attributed to both groups. Virus shedding in nasal and ocular secretions were also similar, apart from a significant difference in nasal virus shedding on day 1 to 3 post-inoculation, which was higher for BHV-1.1 than for BHV-1.2a. Following corticosteroid induced reactivation of the latent infection, recrudescence of clinical signs was also observed, with no significant differences on both groups. It was concluded that both subtypes BHV-1.1 and BHV-1.2a were able to induce clinically undistinguishable respiratory disease in calves, either subsequent to a primary infection or following reactivation.

Abstract in English:

ABSTRACT.- Araújo ER., Madruga C.R., Soares e.o. & Kessler R.H. 2003. [Progresses in immunization against Anaplasma marginale] Progressos na imunização contra Anaplasma marginale. Pesquisa Veterinária Brasileira23(3):139-148. Embrapa Gado de Corte, Cx. Postal 154, Campo Grande, MS 79002-970, Brazil. E-mail: flabio@cnpgc.embrapa.br The current immunization against anaplasmosis in cattle is derived from the blood of infected animais, as live or dead organisms. Nevertheless, efforts have been made to develop a new generation of vaccines. Toe outer membrane of Anaplasma marginale induces a protective immune response against challenge with homologous isolates and a partially protective response against heterologous challenge. ln this membrane, six major surface proteins (MSPs) have been identified, which · have been targeted for the development of immunogens against anaplasmosis. From those proteins, MSP1 a and MSP2 have shown the greatest potential as immunogens, protecting cattle against challenge with virulent homologous and heterologous isolates of A. marginale, despite the size polymorphism of the former protein and the variability of the gene that encodes the latter protein. Another alternative of immunogen is the in vitro culture of A. marginale. lnactivated organisms originating from Dermacentor variabilis IDE8 cell culture were tested as immunogen. Cattle immunized with cell culture-derived A. marginale had a significantly lower reduction in the packed cell volume after challenge exposure and did not display clinical anaplasmosis. Besides the protection afforded by this type of immunogen, cell culture derived organisms are free from bovine cells and pathogens, what is a major advantage as compared with traditional immunization procedures.

• Anaplasma marginale Ehrlichiae immunization bovine major surface proteins culture imunização bovino proteínas principais de superfície cultura.

Abstract in Portuguese:

RESUMO.- Araújo ER., Madruga C.R., Soares e.o. & Kessler R.H. 2003. [Progresses in immunization against Anaplasma marginale] Progressos na imunização contra Anaplasma marginale. Pesquisa Veterinária Brasileira23(3):139-148. Embrapa Gado de Corte, Cx. Postal 154, Campo Grande, MS 79002-970, Brazil. E-mail: flabio@cnpgc.embrapa.br Até o presente momento, as imunizações contra anaplasmose em rebanhos bovinos utilizam organismos vivos ou mortos. No entanto, esforços têm sido realizados nos últimos anos com o objetivo de desenvolver uma nova geração de vacinas. A membrana externa de Anaplasma marginale é capaz de induzir reposta imune protetora contra desafio homólogo e parcialmente protetora contra desafio heterólogo. Nela foram identificadas seis proteínas principais de superfície (MSPs), as quais têm sido alvo de estudos para o desenvolvimento de imunógenos contra a anaplasmose. Destas proteínas, MSPla e MSP2 têm demonstrado maior potencial como imunógenos, protegendo os animais contra desafio com isolados virulentos homólogos e heterólogos de A margina/e, apesar do polimorfismo de tamanho da primeira proteína e variabilidade do gene que codifica a segunda. Uma outra alternativa para a imunização contra A. margina/e é o cultivo in vitro dessa riquétsia. Organismos inativados provenientes de cultivo em células IDE8 de Dermacentor variabilis foram testados como imunógeno. Os animais apresentaram uma significativa diferença na redução do volume globular após desafio e não apresentaram sinais clínicos de anaplasmose. Além da proteção conferida por este tipo de imunógeno, os organismos provenientes de cultura de células de carrapato são livres de células. e patógenos de bovinos, o que é uma vantagem significativa quando comparado aos processos tradicionais de imunização.

Abstract in English:

ABSTRACT.- Bonel-Raposoj., Driemeier D., Barros S.S. & Gevehr~Fernandes C. 2003. [Histological and ultrastructural evolution of liver lesions in experimental Myoporum laetum poisoning of sheep and cattle.] Evolução das lesões histológicas e ultra-estruturais no fígado de ovinos e bovinos experimentalmente intoxicados por Myoporum laetum. Pesquisa Veterinária Brasileira 23(4):149-155. Depto Patologia Animal, Faculdade de Veterinária, UFPel, Pelotas, RS 96010-900, Brazil. E-mail: bonel-raposo@brturbo.com Green leaves of Myoporum laetum were collected during spring and summer, and administered to five sheep and six steers at dosages of 20 and 30 g/kg. Liver biopsies were taken before (Controls) and 1, 3 and 7 days after dosage. ln sheep, the clinicai signs were depression, rumen hypomotility, dried feces, tenesmus, teeth grinding, dyspnea and typical lesions of photosensitization. ln cattle, the clinicai picture was much less pronounced. The main histological findings in sheep were vacuolization of hepatocytes, portal ftbrosis, bile duct proliferation and necrosis of periportal hepatocytes; the ultrastructural examination revealed hyperplasia of the smooth endoplasmic reticulum, hepatocellular hydropic degeneration, presence of crystals and severa! other degenerative changes. ln cattle both, the histological and the ultrastructural findings, were less evident.

• Poisonous plants plant poisoning Myoporum laetum sheep cattle Plantas tóxicas intoxicação por plantas ovinos bovinos.

Abstract in Portuguese:

RESUMO.- Bonel-Raposoj., Driemeier D., Barros S.S. & Gevehr~Fernandes C. 2003. [Histological and ultrastructural evolution of liver lesions in experimental Myoporum laetum poisoning of sheep and cattle.] Evolução das lesões histológicas e ultra-estruturais no fígado de ovinos e bovinos experimentalmente intoxicados por Myoporum laetum. Pesquisa Veterinária Brasileira 23(4):149-155. Depto Patologia Animal, Faculdade de Veterinária, UFPel, Pelotas, RS 96010-900, Brazil. E-mail: bonel-raposo@brturbo.com Amostras de Myoporum laetum foram colhidas durante a primavera e verão e administradas a cinco ovinos e seis bovinos em doses únicas de 20 e 30 g/kg. Biópsias hepáticas foram colhidas antes (controles) e 1, 3 e 7 dias após a dosagem da planta. Estas biópsias foram analisadas histológica e ultraestruturalmente. Os sinais clínicos, em ovinos, caracterizaramse, especialmente; pordepressão, diminuição dos movimentos ruminais, fezes ressequidas, tenesmo, ranger de dentes, dispnéia e lesões típicas de fotossensibilização. Em bovinos, o quadro clínico foi discreto. Os principais achados histológicos, em ovinos, incluíram vacuolização de hepatócitos, fibrose portal, proliferação de duetos biliares e necrose de hepatócitos periportais. Os estudos ultra-estruturais, em ovinos, revelaram hiperplasia do retículo endoplasmático liso, tumefação de hepatócitos, degranulação e vesiculação do retículo endoplasmático rugoso, presença de cristais aciculares, retenção biliar, tumefação de mitocôndrias e várias outras alterações degenerativas. Em bovinos, tanto os achados histológicos, quanto os ultra-estruturais foram menos evidentes.