PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Oliveira A., Fonseca A.H., Ishikawa M.M. & Yoshinari N.H. 2004. [Cinetic growth of Borrelia burgdorferi (Spirochaetaceae) in different culture media.] Cinética do crescimento de Borrelia burgdorferi em diferentes meios de cultivo. Pesquisa Veterinária Brasileira 24(2):61-64. Depto Epidemiologia e Saúde Pública, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: adivaldo@ufrrj.br The cinetic of growth of Borrelia burgdorferi was studied during a 3-month period, using the following 8 culture media: (1) rabbit serum BSK, (2) swine serum BSK, (3) swine serum BSK+5 fluorouracil, (4) PMR, (5) CTB, (6) Dubos, (7) Brucella broth and (8) BHI. All media were prepared aseptically and were maintained in culture tubes of 10 ml capacity. For each medium, the inoculum was standardized to contain initially 102 spirochetes for each 0.1 ml of culture. The growth was monitorized by counting the total number of spirochetes in 0.1ml of medium in a dark field microscope, using a 10x30 mm cover slip. For the first 12 days, counting was done each 24 hours, and afterwards once a week during 14 weeks. There occurred growth of B. burgdorferi in all tested media, with the best performance of three of them: BSK with rabbit serum, BSK swine serum + 5 fluorouracil, and CTB medium. Growth of B. burgdorferi was seen from the 4th week on, reaching its maximum within 8-12 weeks, depleting the culture medium after this time. Cystic forms of B. burgdorferi were observed with all tested media.

• Culture medium Borrelia burgdorferi borreliosis Spirochaetaceae bacteria cultivation cinetic growth cystic forms.

Abstract in Portuguese:

Oliveira A., Fonseca A.H., Ishikawa M.M. & Yoshinari N.H. 2004. [Cinetic growth of Borrelia burgdorferi (Spirochaetaceae) in different culture media.] Cinética do crescimento de Borrelia burgdorferi em diferentes meios de cultivo. Pesquisa Veterinária Brasileira 24(2):61-64. Depto Epidemiologia e Saúde Pública, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: adivaldo@ufrrj.br The cinetic of growth of Borrelia burgdorferi was studied during a 3-month period, using the following 8 culture media: (1) rabbit serum BSK, (2) swine serum BSK, (3) swine serum BSK+5 fluorouracil, (4) PMR, (5) CTB, (6) Dubos, (7) Brucella broth and (8) BHI. All media were prepared aseptically and were maintained in culture tubes of 10 ml capacity. For each medium, the inoculum was standardized to contain initially 102 spirochetes for each 0.1 ml of culture. The growth was monitorized by counting the total number of spirochetes in 0.1ml of medium in a dark field microscope, using a 10x30 mm cover slip. For the first 12 days, counting was done each 24 hours, and afterwards once a week during 14 weeks. There occurred growth of B. burgdorferi in all tested media, with the best performance of three of them: BSK with rabbit serum, BSK swine serum + 5 fluorouracil, and CTB medium. Growth of B. burgdorferi was seen from the 4th week on, reaching its maximum within 8-12 weeks, depleting the culture medium after this time. Cystic forms of B. burgdorferi were observed with all tested media.

Abstract in English:

Lázaro N.S., Tibana A., Reis E.M.F., Rodrigues D.P., Quintaes B.R. & Hofer E. 2004. [Antimicrobial susceptibility pattern and plasmid profile in Salmonella Muenster isolated from swine and abattoir environment, Brazil.] Padrão de susceptibilidade a antimicrobianos e perfil plasmidial em Salmonella Muenster isoladas de suínos e do ambiente de abatedouros. Pesquisa Veterinária Brasileira 24(2):65-70. Depto Epidemiologia e Saúde Pública, Inst.Veterinária, UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: nslazaro@aol.com Thirty-eight strains of Salmonella Muenster, isolated from swine and the abattoir environment, in the State of Rio de Janeiro, Brazil, from March 1991 to February 1992, were analyzed for the presence of plasmids. The strains were selected according to their profile regarding the antimicrobials: streptomycin, tetracycline, sulphonamide and sulfametoxazole-trimethoprim. Thirteen strains were resistant to one or several antimicrobials, 18 with intermediate degree and seven were sensitive. Plasmids varying in size from 1.2 Kb to 42 Kb were detected in 37 (97.36%) of the 38 samples, corresponding to 11 different profiles (P1- P11), varying from 1 to 6 plasmids per model. The number and plasmids diversity was greater than the resistance marks for strains. The plasmid of 2.85 Kb was the most frequent, being present in 83.78% of the 37 strains; only the one of 7.5 Kb was detected at the two slaughterhouses. There was no parallelism between resistance pattern and plasmidial profile, and a same antibiotype was found in several plasmidial profiles. The results of the present investigation, allowed us to conclude that the plasmid characterization is an useful and simple tool for the epidemiological typing of this sorovar.

• Salmonella Muenster swine antimicrobial resistance plasmids.

Abstract in Portuguese:

Lázaro N.S., Tibana A., Reis E.M.F., Rodrigues D.P., Quintaes B.R. & Hofer E. 2004. [Antimicrobial susceptibility pattern and plasmid profile in Salmonella Muenster isolated from swine and abattoir environment, Brazil.] Padrão de susceptibilidade a antimicrobianos e perfil plasmidial em Salmonella Muenster isoladas de suínos e do ambiente de abatedouros. Pesquisa Veterinária Brasileira 24(2):65-70. Depto Epidemiologia e Saúde Pública, Inst.Veterinária, UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: nslazaro@aol.com Thirty-eight strains of Salmonella Muenster, isolated from swine and the abattoir environment, in the State of Rio de Janeiro, Brazil, from March 1991 to February 1992, were analyzed for the presence of plasmids. The strains were selected according to their profile regarding the antimicrobials: streptomycin, tetracycline, sulphonamide and sulfametoxazole-trimethoprim. Thirteen strains were resistant to one or several antimicrobials, 18 with intermediate degree and seven were sensitive. Plasmids varying in size from 1.2 Kb to 42 Kb were detected in 37 (97.36%) of the 38 samples, corresponding to 11 different profiles (P1- P11), varying from 1 to 6 plasmids per model. The number and plasmids diversity was greater than the resistance marks for strains. The plasmid of 2.85 Kb was the most frequent, being present in 83.78% of the 37 strains; only the one of 7.5 Kb was detected at the two slaughterhouses. There was no parallelism between resistance pattern and plasmidial profile, and a same antibiotype was found in several plasmidial profiles. The results of the present investigation, allowed us to conclude that the plasmid characterization is an useful and simple tool for the epidemiological typing of this sorovar.

Abstract in English:

Lemos E.R.S., D'Andrea P.S., Bonvicino C. R., Famadas K. M., Padula P., Cavalcanti A.A. & Schatzmayr H.G. 2004. Evidence of hantavirus infection in wild rodents captured in a rural area of the state of São Paulo, Brazil. Pesquisa Veterinária Brasileira 24(2):71-73. Depto Virologia, Instituto Oswaldo Cruz, Av. Brasil 4365, Pavilhão Rocha Lima, 5º andar, Manguinhos, Rio de Janeiro, RJ, 21045-900, Brazil. E-mail: elemos@ioc.fiocruz.br Hantaviruses are the etiological agents of the Hantavirus Cardio-Pulmonary Syndrome, a serious rodent-borne disease in Brazil. In order to investigate the occurrence of hantavirus infection in wild rodents, a survey was conducted in three different suburban areas of the municipality of Pedreira, State of São Paulo, Brazil. Of the 145 wild animals captured belonging to 12 different species identified by morphology and karyological analysis, 107 were rodents of the following species: Akodon montensis, Bolomys lasiurus, Calomys tener, Oligoryzomys nigripes, Oligoryzomys flavescens, and Myocastor coypus. Blood samples from these rodents were assayed for the presence of antibodies against hantavirus by IgG ELISA using Andes recombinant nucleocapsid antigen. Antibody reactive to Andes virus was found in two different species, O. nigripes and O. flavescens. These results indicate a potential risk for hantavirus transmission to humans in this area, where reservoir rodents are present in peridomestic settings.

• Hantavirus rodent survey Pedreira São Paulo Brazil.

Abstract in Portuguese:

Lemos E.R.S., D'Andrea P.S., Bonvicino C. R., Famadas K. M., Padula P., Cavalcanti A.A. & Schatzmayr H.G. 2004. Evidence of hantavirus infection in wild rodents captured in a rural area of the state of São Paulo, Brazil. Pesquisa Veterinária Brasileira 24(2):71-73. Depto Virologia, Instituto Oswaldo Cruz, Av. Brasil 4365, Pavilhão Rocha Lima, 5º andar, Manguinhos, Rio de Janeiro, RJ, 21045-900, Brazil. E-mail: elemos@ioc.fiocruz.br Hantaviruses are the etiological agents of the Hantavirus Cardio-Pulmonary Syndrome, a serious rodent-borne disease in Brazil. In order to investigate the occurrence of hantavirus infection in wild rodents, a survey was conducted in three different suburban areas of the municipality of Pedreira, State of São Paulo, Brazil. Of the 145 wild animals captured belonging to 12 different species identified by morphology and karyological analysis, 107 were rodents of the following species: Akodon montensis, Bolomys lasiurus, Calomys tener, Oligoryzomys nigripes, Oligoryzomys flavescens, and Myocastor coypus. Blood samples from these rodents were assayed for the presence of antibodies against hantavirus by IgG ELISA using Andes recombinant nucleocapsid antigen. Antibody reactive to Andes virus was found in two different species, O. nigripes and O. flavescens. These results indicate a potential risk for hantavirus transmission to humans in this area, where reservoir rodents are present in peridomestic settings.

Abstract in English:

Bessa M.C., Costa M. & Cardoso M. 2004. [Prevalence of Salmonella sp. carrier pigs in slaughterhouses of Rio Grande do Sul, Brazil.] Prevalência de Salmonella sp em suínos abatidos em frígoríficos do Rio Grande do Sul. Pesquisa Veterinária Brasileira 24(2):80-84. Depto Medicina Veterinária Preventiva, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: mcardoso@vortex.ufrgs.br This study aimed to determine the prevalence of Salmonella positive pigs at slaughterhouses under federal inspection in Rio Grande do Sul, Brazil. Samples of feces and lymph nodes of 300 animals were collected in three different slaughterhouses, and submitted to bacteriological analysis. The prevalence of Salmonella carrier animals was 55.66%, being 17.6% of the animals Salmonella positive in lymph nodes, 18.3% in feces and 19.6% in both materials. Twenty-six different serovars were identified among 226 Salmonella isolates. The most prevalent serovars were: Typhimurium (24.3%), Agona (19.9%), Derby (13.2%) e Bredeney (12%). These results point out the need of control programs to reduce the prevalence of carrier pigs at slaughter.

• Salmonella swine lymph nodes feces.

Abstract in Portuguese:

Bessa M.C., Costa M. & Cardoso M. 2004. [Prevalence of Salmonella sp. carrier pigs in slaughterhouses of Rio Grande do Sul, Brazil.] Prevalência de Salmonella sp em suínos abatidos em frígoríficos do Rio Grande do Sul. Pesquisa Veterinária Brasileira 24(2):80-84. Depto Medicina Veterinária Preventiva, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: mcardoso@vortex.ufrgs.br This study aimed to determine the prevalence of Salmonella positive pigs at slaughterhouses under federal inspection in Rio Grande do Sul, Brazil. Samples of feces and lymph nodes of 300 animals were collected in three different slaughterhouses, and submitted to bacteriological analysis. The prevalence of Salmonella carrier animals was 55.66%, being 17.6% of the animals Salmonella positive in lymph nodes, 18.3% in feces and 19.6% in both materials. Twenty-six different serovars were identified among 226 Salmonella isolates. The most prevalent serovars were: Typhimurium (24.3%), Agona (19.9%), Derby (13.2%) e Bredeney (12%). These results point out the need of control programs to reduce the prevalence of carrier pigs at slaughter.

Abstract in English:

Beltrão N., Furian T.Q., Leão J.A., Pereira R.A., Moraes L.B. & Canal C.W. 2004. [Detection of infectious laryngotracheitis virus in chickens in Brazil.] Detecção do vírus da laringotraqueíte das galinhas no Brasil. Pesquisa Veterinária Brasileira 24(2):85-88. Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Faculdade de Veterinária, UFRGS, Porto Alegre, RS 91540-000, Brazil. E-mail: nilzaneb@hotmail.com A study was carried out in search for evidences of infectious laryngotracheitis virus (ILTV) infections in some Brazilian chicken flocks. Tracheal tissues and swabs were collected from 10 different flocks of layers and broilers displaying respiratory signs of disease. Samples were processes for virus isolation in embryonated eggs and the membranes examined by histopathology. In addition, specimens were examined by polymerase chain reaction (PCR). Three flocks had ILTV positive chickens by virus isolation and PCR. These results confirm the occurrence of ILTV in chickens in Brazil.

• Infectious laryngotracheitis virus PCR virus isolation avian pathology.

Abstract in Portuguese:

Beltrão N., Furian T.Q., Leão J.A., Pereira R.A., Moraes L.B. & Canal C.W. 2004. [Detection of infectious laryngotracheitis virus in chickens in Brazil.] Detecção do vírus da laringotraqueíte das galinhas no Brasil. Pesquisa Veterinária Brasileira 24(2):85-88. Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Faculdade de Veterinária, UFRGS, Porto Alegre, RS 91540-000, Brazil. E-mail: nilzaneb@hotmail.com A study was carried out in search for evidences of infectious laryngotracheitis virus (ILTV) infections in some Brazilian chicken flocks. Tracheal tissues and swabs were collected from 10 different flocks of layers and broilers displaying respiratory signs of disease. Samples were processes for virus isolation in embryonated eggs and the membranes examined by histopathology. In addition, specimens were examined by polymerase chain reaction (PCR). Three flocks had ILTV positive chickens by virus isolation and PCR. These results confirm the occurrence of ILTV in chickens in Brazil.

Abstract in English:

Canal C.W., Ferreira D.J., Macagnan M., Fallavena L.C.B., Moraes H.L.S. & Wald V.B. 2004. Prevalence of antibodies against chicken anaemia virus (CAV) in broiler breeders in Southern Brazil. Pesquisa Veterinária Brasileira 24(2):89-92. Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Faculdade de Veterinária da Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 91540-000, Brazil. E-mail: claudio.canal@ufrgs.br Chicks infected during the first two weeks of life with chicken anaemia virus (CAV) manifest clinical disease that can be avoided if the breeder hens transfer enough antibodies to their progeny. The objective of the present work was to establish the prevalence and titer of anti-CAV antibodies in some Brazilian broiler hen breeder flocks and verify in which phase of life the birds were infected. A total of 1,709 serum samples from 12 broiler hen flocks vaccinated against CAV and 64 unvaccinated flocks were analyzed for CAV antibodies with an enzyme-linked immunosorbent assay (ELISA). All non-vaccinated breeder flocks were found to be infected with CAV, with 89% of the hens tested presenting antibodies, 52% of these with titers considered high enough to protect their progeny against CAV infection. Likewise, all vaccinated hens had antibody titer to CAV capable of conferring protection to their progeny. Thus, vaccination of hens seems capable of conferring protection to chicks against clinically apparent CAV-associated disease.

• Antibodies avian pathology chicken anemia virus CAV epidemiology prevalence.

Abstract in Portuguese:

Canal C.W., Ferreira D.J., Macagnan M., Fallavena L.C.B., Moraes H.L.S. & Wald V.B. 2004. Prevalence of antibodies against chicken anaemia virus (CAV) in broiler breeders in Southern Brazil. Pesquisa Veterinária Brasileira 24(2):89-92. Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Faculdade de Veterinária da Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 91540-000, Brazil. E-mail: claudio.canal@ufrgs.br Chicks infected during the first two weeks of life with chicken anaemia virus (CAV) manifest clinical disease that can be avoided if the breeder hens transfer enough antibodies to their progeny. The objective of the present work was to establish the prevalence and titer of anti-CAV antibodies in some Brazilian broiler hen breeder flocks and verify in which phase of life the birds were infected. A total of 1,709 serum samples from 12 broiler hen flocks vaccinated against CAV and 64 unvaccinated flocks were analyzed for CAV antibodies with an enzyme-linked immunosorbent assay (ELISA). All non-vaccinated breeder flocks were found to be infected with CAV, with 89% of the hens tested presenting antibodies, 52% of these with titers considered high enough to protect their progeny against CAV infection. Likewise, all vaccinated hens had antibody titer to CAV capable of conferring protection to their progeny. Thus, vaccination of hens seems capable of conferring protection to chicks against clinically apparent CAV-associated disease.

Abstract in English:

Garmatz S.L., Irigoyen L.F., Rech R.R., Brown C.C., Zhang J. & Barros C.S.L. 2004. [Malignant catarrhal fever in cattle in Rio Grande do Sul, Brazil: Experimental transmission to cattle and characterization of the etiological agent.] Febre catarral maligna em bovinos no Rio Grande do Sul: transmissão experimental para bovinos e caracterização do agente etiológico. Pesquisa Veterinária Brasileira 24(2):93-106. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two oubreaks of malignant catarrhal fever (MCF) occurring in cattle on two farms (A and B) in the municipality of Santiago, state of Rio Grande do Sul (RS), Brazil, and the transmission of the disease to susceptible calves as well as the detection of ovine herpesvirus-2 (OvHV-2) in tissues of affected cattle are reported. The two epizootics occurred from November 2001 to February 2002 (Farm A) and in January-February 2003 (Farm B). Numbers of cattle at risk, morbidity and letality rates were respectively 170, 10.59% and 83.33% for Farm A and 500, 2.4% and 100% for Farm B. Contact between affected cattle and sheep was detected in both farms, but lambing ewes were present only in farm A. Duration of clinical courses, gross findings and histopathology were the same for the affected cattle in both farms. Most affected cattle died or were euthanatized in extremis after a clinical course of 2-8 days. Clinical signs included fever (40.5 and 41.5°C), nasal and ocular discharge, corneal opacity, conjunctivitis, drooling, erosions and ulcerations of the mucosae, diarrhea, hematuria, and neurological disturbances. Eleven necropsies (9 on Farm A, 2 on Farm B) were performed. Gross lesions included erosions and ulcers affecting the mucosae of nasal turbinates, oral cavity, gastrointestinal and urogenital tracts; hemorrhage and necrosis of the tip of the buccal papillae, lymph node enlargement, multifocal white foci in renal cortex, and hyperemia of leptomeninges. Microscopically, there were arteritis and fibrinoid degeneration in medium and small arteries and arterioles of multiple organs and tissues, necrosis and inflammation in several mucosal surfaces, keratitis, conjunctivitis, uveitis, intersticial nephritis, and encephalitis. Transmission experiments were attempted in five calves (E1-E5) by inocculating each of them intravenously with 500 ml of whole heparinized blood from a MCF affected cow. The transmission was suscessful in at least three (E1-E3) of the experimental calves which became sick after an incubation period of 15-27 days. Four experimental calves either died or were euthanatized in extremis after a clinical course which varied from 3 days to 8 weeks. The remaining experimental calf (E5) recovered from a mild disease and was euthanatized 14 weeks after inocculation. Necropsies were performed in all five calves. Clinical signs, necropsy and histopathological findings of three calves (E1-E3) were characteristic of MCF. OvHV-2 viral DNA was detected by the polimerase chain reaction (PCR) test in paraffin embedded tissues from seven cattle out of the 11 spontaneous MCF cases and from three experimental calves (E1-E3). PCR tests resulted negative in the remaining four of the 11 spontaneous MCF cases tested and in two (E4,E5) of the five experimental calves. Immunohistochemistry performed in sections of lymphoid tissue from calf E4 failed to detect BVD virus antigen. The experimental transmission of MCF and the characterization of the etiological agent as OvHV-2 were successfully attempted in cattle for the first time in Brazil.

• Infectious diseases malignant catarrhal fever viral diseases diseases of cattle pathology polimerase chain reation.

Abstract in Portuguese:

Garmatz S.L., Irigoyen L.F., Rech R.R., Brown C.C., Zhang J. & Barros C.S.L. 2004. [Malignant catarrhal fever in cattle in Rio Grande do Sul, Brazil: Experimental transmission to cattle and characterization of the etiological agent.] Febre catarral maligna em bovinos no Rio Grande do Sul: transmissão experimental para bovinos e caracterização do agente etiológico. Pesquisa Veterinária Brasileira 24(2):93-106. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two oubreaks of malignant catarrhal fever (MCF) occurring in cattle on two farms (A and B) in the municipality of Santiago, state of Rio Grande do Sul (RS), Brazil, and the transmission of the disease to susceptible calves as well as the detection of ovine herpesvirus-2 (OvHV-2) in tissues of affected cattle are reported. The two epizootics occurred from November 2001 to February 2002 (Farm A) and in January-February 2003 (Farm B). Numbers of cattle at risk, morbidity and letality rates were respectively 170, 10.59% and 83.33% for Farm A and 500, 2.4% and 100% for Farm B. Contact between affected cattle and sheep was detected in both farms, but lambing ewes were present only in farm A. Duration of clinical courses, gross findings and histopathology were the same for the affected cattle in both farms. Most affected cattle died or were euthanatized in extremis after a clinical course of 2-8 days. Clinical signs included fever (40.5 and 41.5°C), nasal and ocular discharge, corneal opacity, conjunctivitis, drooling, erosions and ulcerations of the mucosae, diarrhea, hematuria, and neurological disturbances. Eleven necropsies (9 on Farm A, 2 on Farm B) were performed. Gross lesions included erosions and ulcers affecting the mucosae of nasal turbinates, oral cavity, gastrointestinal and urogenital tracts; hemorrhage and necrosis of the tip of the buccal papillae, lymph node enlargement, multifocal white foci in renal cortex, and hyperemia of leptomeninges. Microscopically, there were arteritis and fibrinoid degeneration in medium and small arteries and arterioles of multiple organs and tissues, necrosis and inflammation in several mucosal surfaces, keratitis, conjunctivitis, uveitis, intersticial nephritis, and encephalitis. Transmission experiments were attempted in five calves (E1-E5) by inocculating each of them intravenously with 500 ml of whole heparinized blood from a MCF affected cow. The transmission was suscessful in at least three (E1-E3) of the experimental calves which became sick after an incubation period of 15-27 days. Four experimental calves either died or were euthanatized in extremis after a clinical course which varied from 3 days to 8 weeks. The remaining experimental calf (E5) recovered from a mild disease and was euthanatized 14 weeks after inocculation. Necropsies were performed in all five calves. Clinical signs, necropsy and histopathological findings of three calves (E1-E3) were characteristic of MCF. OvHV-2 viral DNA was detected by the polimerase chain reaction (PCR) test in paraffin embedded tissues from seven cattle out of the 11 spontaneous MCF cases and from three experimental calves (E1-E3). PCR tests resulted negative in the remaining four of the 11 spontaneous MCF cases tested and in two (E4,E5) of the five experimental calves. Immunohistochemistry performed in sections of lymphoid tissue from calf E4 failed to detect BVD virus antigen. The experimental transmission of MCF and the characterization of the etiological agent as OvHV-2 were successfully attempted in cattle for the first time in Brazil.

Abstract in English:

Portiansky E.L., Quiroga M.A., Machuca M.A. & Perfumo C.J. 2004. Mycoplasma suis in naturally infected pigs: an ultrastructural and morphometric study. Pesquisa Veterinária Brasileira 24(1):1-5. Instituto de Patología, Faculdad de Ciencias Veterinarias, Universidad Nacional de La Plata, Calle 60 y 118, C.C. 296, (1900) La Plata, Buenos Aires, Argentina. E-mail: elporti@fcv.unlp.edu.ar Swine eperythrozoonosis is a haemotrophic disease caused by Eperythrozoon suis, actually called Mycoplasma suis, an extracellular bacterial organism that apparently adheres to pig erythrocyte membrane, inducing its deformation and damage. Since little is known about the ultrastructural and morphometrical aspects of this microorganism, the present work aimed to deal with these issues. The ultrastructural study revealed the presence of structures corresponding to tubules disseminated throughout the soma of M. suis. A variable separation between the microorganism membrane and that of the erythrocyte was also observed. The structural and positional attitude of M. suis could allow speculation about its mechanism of action.

• Eperythrozoonosis Mycoplasma suis ultrastructure morphometry pathogenesis.

Abstract in Portuguese:

Portiansky E.L., Quiroga M.A., Machuca M.A. & Perfumo C.J. 2004. Mycoplasma suis in naturally infected pigs: an ultrastructural and morphometric study. Pesquisa Veterinária Brasileira 24(1):1-5. Instituto de Patología, Faculdad de Ciencias Veterinarias, Universidad Nacional de La Plata, Calle 60 y 118, C.C. 296, (1900) La Plata, Buenos Aires, Argentina. E-mail: elporti@fcv.unlp.edu.ar Swine eperythrozoonosis is a haemotrophic disease caused by Eperythrozoon suis, actually called Mycoplasma suis, an extracellular bacterial organism that apparently adheres to pig erythrocyte membrane, inducing its deformation and damage. Since little is known about the ultrastructural and morphometrical aspects of this microorganism, the present work aimed to deal with these issues. The ultrastructural study revealed the presence of structures corresponding to tubules disseminated throughout the soma of M. suis. A variable separation between the microorganism membrane and that of the erythrocyte was also observed. The structural and positional attitude of M. suis could allow speculation about its mechanism of action.

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.- 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.