PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Rozza D.B., Corrêa A.M.R., Leal J.S., Bandarra P.M., Guagnini F.S. & Djeison Lutier Raymundo D.L. & Driemeier D. 2007. [Experimental monensin poisoning in water buffaloes (Bubalus bubalis) and cattle.] Intoxicação experimental por monensina em búfalos e bovinos. Pesquisa Veterinária Brasileira 27(4):172-178. Departamento de Patologia Clínica Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br Monensin is widely used as a feed additive to improve performance of livestock; however accidental poisoning by this ionophore compound has been reported in a number of animal species. Typical clinical signs and lesions of monensin poisoning were induced in water buffaloes dosed with single dosages of 15, 10, 7.5, and 5mg/kg of the compound. Only buffaloes dosed with 2.5 mg/kg (1 day) and 1mg/kg (7 days) survived. Clinical signs initiated about 6 h post-dosing and included apathy, anorexia, diarrhea, drooling, muscular weakness, locomotion disorders, dyspnea, tachycardia, jugular distension and pulse, recumbency and death. The creatine kinase (CK) levels were highly augmented in blood samples of buffaloes dosed with monensin. Most prominent gross changes were ascites, hydrothorax, hydropericardium, cardiomegaly, hepatomegaly, and focal pale areas in the myocardium and in skeletal muscles. Degeneration and necrosis of myofibers were the principal histopathological findings. Conversely, no evidence of disease, neither change in CK levels were observed in the beef cattle steers dosed with same doses, confirming preliminary findings that buffaloes are more susceptible to monensin than cattle. In addition, this communication presents the minimal toxic dosage of monensin to buffaloes and suggests that CK tests may serve as health monitoring tools in the management of buffalo herds supplemented with monensin.

• Buffaloes cattle CK levels degenerative myopathy monensin toxicity monensin tolerance

Abstract in Portuguese:

ABSTRACT.- Rozza D.B., Corrêa A.M.R., Leal J.S., Bandarra P.M., Guagnini F.S. & Djeison Lutier Raymundo D.L. & Driemeier D. 2007. [Experimental monensin poisoning in water buffaloes (Bubalus bubalis) and cattle.] Intoxicação experimental por monensina em búfalos e bovinos. Pesquisa Veterinária Brasileira 27(4):172-178. Departamento de Patologia Clínica Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br Monensin is widely used as a feed additive to improve performance of livestock; however accidental poisoning by this ionophore compound has been reported in a number of animal species. Typical clinical signs and lesions of monensin poisoning were induced in water buffaloes dosed with single dosages of 15, 10, 7.5, and 5mg/kg of the compound. Only buffaloes dosed with 2.5 mg/kg (1 day) and 1mg/kg (7 days) survived. Clinical signs initiated about 6 h post-dosing and included apathy, anorexia, diarrhea, drooling, muscular weakness, locomotion disorders, dyspnea, tachycardia, jugular distension and pulse, recumbency and death. The creatine kinase (CK) levels were highly augmented in blood samples of buffaloes dosed with monensin. Most prominent gross changes were ascites, hydrothorax, hydropericardium, cardiomegaly, hepatomegaly, and focal pale areas in the myocardium and in skeletal muscles. Degeneration and necrosis of myofibers were the principal histopathological findings. Conversely, no evidence of disease, neither change in CK levels were observed in the beef cattle steers dosed with same doses, confirming preliminary findings that buffaloes are more susceptible to monensin than cattle. In addition, this communication presents the minimal toxic dosage of monensin to buffaloes and suggests that CK tests may serve as health monitoring tools in the management of buffalo herds supplemented with monensin.

Abstract in English:

ABSTRACT.- Ferrigno C.R.A.,Della Nina M.I. & Fantoni D.T. 2007. [A comparative study of osteosynthesis with plates and plates associated with grafts of bone morphogenic proteins (Gen-Techâ) in distal radio-ulna fractures in dogs with less than 6 quilograms.] Estudo comparativo entre as osteossínteses com placas e osteossínteses com placas associadas a enxertos de proteína morfogenética óssea (Gen-Techâ) em fraturas distais de rádio-ulna em cães com menos de 6 quilos. Pesquisa Veterinária Brasileira 27(2):65-69. Departamento de Cirurgia do Hospital Veterinário, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, SP 05508-900. E-mail: cassioaf@usp.br It is well known that bone morphogenic proteins (BMP) cause osteogenesis, yet clinical research must be performed in order to really show their benefits. Animals weighing less than 6 kg show well known difficulties regarding radius and ulna fracture repair mainly with bone non-union, due to poor vascularization of the distal portion of the radius. Therefore this study aimed to compare the velocity of bone callus formation in the treatment of fracture repair with plates and screws alone or with plates and screws plus BMP. Thirty three dogs with radius and ulna fractures were distributed into two groups, where animals of the control group received the conservative treatment performed with screws and plates alone, whilst the other group received the conservative treatment and BMP. The time of bone callus formation was evaluated comparatively through radiographic exams 30, 60, 90, 120, 180 and 210 days after the surgical procedure. Animals treated with BMP showed a healing time of 32±15 days, which was significantly different (p <0.001) from the control group which required 127±34 days. With the results obtained, it can be concluded that the distal radio-ulna fractures of dogs weighing less than 6 kg suffered a significant reduction of the bone callus formation time, which was around 90 days.

• Bone morphogenic proteins BMP bone fractures bone plate dogs

Abstract in Portuguese:

ABSTRACT.- Ferrigno C.R.A.,Della Nina M.I. & Fantoni D.T. 2007. [A comparative study of osteosynthesis with plates and plates associated with grafts of bone morphogenic proteins (Gen-Techâ) in distal radio-ulna fractures in dogs with less than 6 quilograms.] Estudo comparativo entre as osteossínteses com placas e osteossínteses com placas associadas a enxertos de proteína morfogenética óssea (Gen-Techâ) em fraturas distais de rádio-ulna em cães com menos de 6 quilos. Pesquisa Veterinária Brasileira 27(2):65-69. Departamento de Cirurgia do Hospital Veterinário, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, SP 05508-900. E-mail: cassioaf@usp.br It is well known that bone morphogenic proteins (BMP) cause osteogenesis, yet clinical research must be performed in order to really show their benefits. Animals weighing less than 6 kg show well known difficulties regarding radius and ulna fracture repair mainly with bone non-union, due to poor vascularization of the distal portion of the radius. Therefore this study aimed to compare the velocity of bone callus formation in the treatment of fracture repair with plates and screws alone or with plates and screws plus BMP. Thirty three dogs with radius and ulna fractures were distributed into two groups, where animals of the control group received the conservative treatment performed with screws and plates alone, whilst the other group received the conservative treatment and BMP. The time of bone callus formation was evaluated comparatively through radiographic exams 30, 60, 90, 120, 180 and 210 days after the surgical procedure. Animals treated with BMP showed a healing time of 32±15 days, which was significantly different (p <0.001) from the control group which required 127±34 days. With the results obtained, it can be concluded that the distal radio-ulna fractures of dogs weighing less than 6 kg suffered a significant reduction of the bone callus formation time, which was around 90 days.

Abstract in English:

ABSTRACT.- Brito L.G., Regitano L.C.A., Huacca M.E.F., Carrilho E. & Moya Borja G.E. 2007. Genotype characterization of the horn fly Haematobia irritans from different Brazilian geographic regions based on randomly amplified polymorphic DNA (RAPD) analysis. Pesquisa Veterinária Brasileira 27(1):1-5. Laboratório de Sanidade Animal, Embrapa Rondônia, BR 364 Km 5,5, Porto Velho, RO 78900-970, Brazil. E-mail: luciana@cpafro.embrapa.br Blood-sucking diptera are important parasites in bovine production systems, especially regarding confinement conditions. Haematobia irritans, the horn fly, is one of the most troublesome species within bovine production systems, due to the intense stress imposed to the animals. An important aspect while studying the variability within a species is the study of the geographic structure of its populations and, attempting to find out the genetic flow of Brazilian populations of horn fly, the RAPD technique, which is suited for this purpose, has been used. The use of molecular markers generated from RAPD made it possible to identify the geographic origin of samples from different Brazilian geographic regions, as well as to estimate the genotypic flow among the different Brazilian populations of the horn fly.

• Haematobia irritans genetic diversity RAPD-PCR molecular markers

Abstract in Portuguese:

ABSTRACT.- Brito L.G., Regitano L.C.A., Huacca M.E.F., Carrilho E. & Moya Borja G.E. 2007. Genotype characterization of the horn fly Haematobia irritans from different Brazilian geographic regions based on randomly amplified polymorphic DNA (RAPD) analysis. Pesquisa Veterinária Brasileira 27(1):1-5. Laboratório de Sanidade Animal, Embrapa Rondônia, BR 364 Km 5,5, Porto Velho, RO 78900-970, Brazil. E-mail: luciana@cpafro.embrapa.br Blood-sucking diptera are important parasites in bovine production systems, especially regarding confinement conditions. Haematobia irritans, the horn fly, is one of the most troublesome species within bovine production systems, due to the intense stress imposed to the animals. An important aspect while studying the variability within a species is the study of the geographic structure of its populations and, attempting to find out the genetic flow of Brazilian populations of horn fly, the RAPD technique, which is suited for this purpose, has been used. The use of molecular markers generated from RAPD made it possible to identify the geographic origin of samples from different Brazilian geographic regions, as well as to estimate the genotypic flow among the different Brazilian populations of the horn fly.

Abstract in English:

ABSTRACT.- Cortez A., Heinemann M.B., Castro A.M.M.G., Soares M.S, Pinto A.M.V., Alfieri A.A., Flores E.F., Leite R.C. & Richtzenhain L.J. 2006. Genetic characterization of Brazilian bovine viral diarrhea virus isolates by partial nucleotide sequencing of the 5’-UTR region. Pesquisa Veterinária Brasileira 26(4):211-216. Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo, SP 05508-000, Brazil. E-mail: leonardo@usp.br Nineteen isolates of bovine viral diarrhea virus (BVDV) from Brazil were genetically characterized through partial nucleotide sequencing and analysis of the 5’UTR region. The isolates were grouped as BVDV-1 (11/19), BVDV-2 (6/19) or “atypical” pestivirus (2/19). Among the BVDV-1, eight isolates were classified as subgenotype BVDV-1a, whereas most (4 out of 6) BVDV-2 belonged to subgenotype 2b. Two isolates from aborted fetuses were not classified into any genetic group, being considered atypical BVDVs. Genetic diversity among Brazilian BVDV isolates may be responsible for vaccination and diag-nostic failure and therefore may influence the control strategies for BVDV infection in the country.

• BVDV-1 BVDV-2 Pestivirus phylogenetic analysis

Abstract in Portuguese:

ABSTRACT.- Cortez A., Heinemann M.B., Castro A.M.M.G., Soares M.S, Pinto A.M.V., Alfieri A.A., Flores E.F., Leite R.C. & Richtzenhain L.J. 2006. Genetic characterization of Brazilian bovine viral diarrhea virus isolates by partial nucleotide sequencing of the 5’-UTR region. Pesquisa Veterinária Brasileira 26(4):211-216. Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo, SP 05508-000, Brazil. E-mail: leonardo@usp.br Nineteen isolates of bovine viral diarrhea virus (BVDV) from Brazil were genetically characterized through partial nucleotide sequencing and analysis of the 5’UTR region. The isolates were grouped as BVDV-1 (11/19), BVDV-2 (6/19) or “atypical” pestivirus (2/19). Among the BVDV-1, eight isolates were classified as subgenotype BVDV-1a, whereas most (4 out of 6) BVDV-2 belonged to subgenotype 2b. Two isolates from aborted fetuses were not classified into any genetic group, being considered atypical BVDVs. Genetic diversity among Brazilian BVDV isolates may be responsible for vaccination and diag-nostic failure and therefore may influence the control strategies for BVDV infection in the country.

Abstract in English:

ABSTRACT.- Guedes K.M.R., Schild A.L. Riet-Correa F., Barros S.S. & Simões S.V.D. 2006. [Spongious degeneration in the central nervous system in Sindhi calves]. Degeneração esponjosa no sistema nervoso central de bezerros da raça Sindhi. Pesquisa Veterinária Brasileira 26(3):157-160. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, Paraíba, Brazil. E-mail franklin.riet@pesquisador.cnpq.br Spongy degeneration (status spongiosus) includes many histological alterations characterized by vacuoles in the neuropile in different regions of the central nervous system (CNS). The vacuolization can be caused by intramyelinic edema, as in maple syrup urine disease and some toxic diseases, or by astrocytic edema, as in citrullinemia. This paper reports a spongy degeneration in two Sindhi calves, a female and a male. Both calves were offspring from the same bull, and the herd had high degree of inbreeding. The female calf was born normal, but progressive nervous signs were observed since 2 months old. The male calf had progressive nervous signs since it was born. Both calves were euthanized with severe nervous signs when 4 months old. At necropsy the liver was pale in the male calf. Histological alterations were mild to accentuated vacuolization, mainly in the deep cerebral cortex, cerebellar white matter, grey matter of the spinal cord, internal capsule, and brain stem. Fatty degeneration was observed in the liver of both animals. On electron microscopy it was found that the status spongiosus was caused by astrocytic edema. It is suggested that the disease is caused by a metabolic hereditary error.

• Status spongiosus astrocytic edema congenital diseases cattle

Abstract in Portuguese:

ABSTRACT.- Guedes K.M.R., Schild A.L. Riet-Correa F., Barros S.S. & Simões S.V.D. 2006. [Spongious degeneration in the central nervous system in Sindhi calves]. Degeneração esponjosa no sistema nervoso central de bezerros da raça Sindhi. Pesquisa Veterinária Brasileira 26(3):157-160. Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, Paraíba, Brazil. E-mail franklin.riet@pesquisador.cnpq.br Spongy degeneration (status spongiosus) includes many histological alterations characterized by vacuoles in the neuropile in different regions of the central nervous system (CNS). The vacuolization can be caused by intramyelinic edema, as in maple syrup urine disease and some toxic diseases, or by astrocytic edema, as in citrullinemia. This paper reports a spongy degeneration in two Sindhi calves, a female and a male. Both calves were offspring from the same bull, and the herd had high degree of inbreeding. The female calf was born normal, but progressive nervous signs were observed since 2 months old. The male calf had progressive nervous signs since it was born. Both calves were euthanized with severe nervous signs when 4 months old. At necropsy the liver was pale in the male calf. Histological alterations were mild to accentuated vacuolization, mainly in the deep cerebral cortex, cerebellar white matter, grey matter of the spinal cord, internal capsule, and brain stem. Fatty degeneration was observed in the liver of both animals. On electron microscopy it was found that the status spongiosus was caused by astrocytic edema. It is suggested that the disease is caused by a metabolic hereditary error.

Abstract in English:

ABSTRACT.- Seixas J.N., Peixoto P.V., Armién A.G., Jabour F.F. & Brito M.F. 2006. [Clinical and pathogenetic aspects of abamectin poisoning in calves.] Aspectos clínicos e patogenéticos da intoxicação por abamectina em bezerros. Pesquisa Veterinária Brasileira 26(3):161-166. Pro-jeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23890-000, Brazil. E-mail: josiseixas@ufrrj.br Clinic-pathological aspects and the pathogenesis of experimental abamectin poisoning were studied, after subcutaneous administration of different abamectin doses in 9 calves, as well as the clini-cal and pathological aspects of 74 cases of the iatrogenic poisoning with this drug in cattle, which occurred in the states of Rio Grande do Sul, Pará, Maranhão, Paraíba and Mato Grosso do Sul. From the 9 calves submitted to experimental administration of single doses, 5 calves died (4 calves received doses 6-10 times higher than recommended, and one received the therapeutic daily dose during 11 days). Abamectin poisoning induces neurological dysfunctions, characterized by an initial phase of hyperexcitability, followed by widespread muscular hypotony and progressive depression. No macroscopic or microscopic alterations were observed in the central nervous system or in any other organ. It is concluded that abamectin is an antihelmintic which should be used with restriction, because of the risks leading to death when used in young calves, even in therapeutic doses.

• Abamectin poisoning neurological alterations calves

Abstract in Portuguese:

ABSTRACT.- Seixas J.N., Peixoto P.V., Armién A.G., Jabour F.F. & Brito M.F. 2006. [Clinical and pathogenetic aspects of abamectin poisoning in calves.] Aspectos clínicos e patogenéticos da intoxicação por abamectina em bezerros. Pesquisa Veterinária Brasileira 26(3):161-166. Pro-jeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23890-000, Brazil. E-mail: josiseixas@ufrrj.br Clinic-pathological aspects and the pathogenesis of experimental abamectin poisoning were studied, after subcutaneous administration of different abamectin doses in 9 calves, as well as the clini-cal and pathological aspects of 74 cases of the iatrogenic poisoning with this drug in cattle, which occurred in the states of Rio Grande do Sul, Pará, Maranhão, Paraíba and Mato Grosso do Sul. From the 9 calves submitted to experimental administration of single doses, 5 calves died (4 calves received doses 6-10 times higher than recommended, and one received the therapeutic daily dose during 11 days). Abamectin poisoning induces neurological dysfunctions, characterized by an initial phase of hyperexcitability, followed by widespread muscular hypotony and progressive depression. No macroscopic or microscopic alterations were observed in the central nervous system or in any other organ. It is concluded that abamectin is an antihelmintic which should be used with restriction, because of the risks leading to death when used in young calves, even in therapeutic doses.

Abstract in English:

Rissi D.R., Rech R.R., Barros R.R., Kommers G.D., Langohr I.M., Pierezan F. & Barros C.S.L. 2006. [Listeric meningoencephalitis in goats.] Forma nervosa de listeriose em caprinos. Pesquisa Veterinária Brasileira 26(1):14-20. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br A neurologic disease was observed in three young adult goats (indentified as A-C) from a herd of 100 goats during October-December, 2004. Clinical signs included head tilt, torticollis, nystagmus, staggering, falls and eventually recumbency and paddling, with stiff limbs. Treatment of Goat C with antibiotics resulted in a temporary remission of the clinical signs. The clinical courses where 5, 10 and 30 days respectively for Goats A, B and C. Goat A died spontaneously and the other two where euthanatized in extremis. No gross changes were observed. Histologic lesions were predominantly unilateral, with inflammatory and degenerative changes, extending from the medulla oblongata to the thalamus. In all 3 cases there were perivascular cuffings of one or more types of mononuclear cells (lymphocytes, plasma cells, activated macrophages) and occasionally neutrophils associated with areas of malacia where Gitter cells filled spaces of parenchymal loss. Additionally, Goat B had microabscesses in the medulla, pons, and mesencephalon and multifocal neutrophilic and lymphocytic infiltrates within the fascicles of the trigeminal nerve and in the cerebellar leptomeninges. In the brainstem of Goat C, there was multifocal granulomatous inflammation which included epithelioid macrophages and occasional multinucleated giant cells. Listeria sp antigen was detected by imunohistochemistry in routinely processed sections of mesencephalon from Goats A and C and of pons from Goat B.

• Listeria sp Listeria monocytogenes listeriosis encephalitis immunohistochemistry pathology diseases of goats.

Abstract in Portuguese:

Rissi D.R., Rech R.R., Barros R.R., Kommers G.D., Langohr I.M., Pierezan F. & Barros C.S.L. 2006. [Listeric meningoencephalitis in goats.] Forma nervosa de listeriose em caprinos. Pesquisa Veterinária Brasileira 26(1):14-20. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br A neurologic disease was observed in three young adult goats (indentified as A-C) from a herd of 100 goats during October-December, 2004. Clinical signs included head tilt, torticollis, nystagmus, staggering, falls and eventually recumbency and paddling, with stiff limbs. Treatment of Goat C with antibiotics resulted in a temporary remission of the clinical signs. The clinical courses where 5, 10 and 30 days respectively for Goats A, B and C. Goat A died spontaneously and the other two where euthanatized in extremis. No gross changes were observed. Histologic lesions were predominantly unilateral, with inflammatory and degenerative changes, extending from the medulla oblongata to the thalamus. In all 3 cases there were perivascular cuffings of one or more types of mononuclear cells (lymphocytes, plasma cells, activated macrophages) and occasionally neutrophils associated with areas of malacia where Gitter cells filled spaces of parenchymal loss. Additionally, Goat B had microabscesses in the medulla, pons, and mesencephalon and multifocal neutrophilic and lymphocytic infiltrates within the fascicles of the trigeminal nerve and in the cerebellar leptomeninges. In the brainstem of Goat C, there was multifocal granulomatous inflammation which included epithelioid macrophages and occasional multinucleated giant cells. Listeria sp antigen was detected by imunohistochemistry in routinely processed sections of mesencephalon from Goats A and C and of pons from Goat B.

Abstract in English:

Paulovich F.B., Borowski S.M., Driemeier D., Razia L.E., Coutinho T. A., Prates A.B.H., Pescador C., Correa A. & Barcellos D.E.S.N. 2004. [Assessment of the pathogenicity of Brachyspira pilosicoli strains by conventional histopathological techniques and by immunohistochemistry.] Avaliação da patogenicidade de amostras de Brachyspira pilosicoli através de técnicas histopatológicas convencionais e por imuno-histoquímica. Pesquisa Veterinária Brasileira 24(3):144-148. Depto Patologia Clínica Veterinária, Faculdade de Veterinária, UFRGS, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@vortex.ufrgs.br The study assessed differences of pathogenicity among 19 strains of Brachyspira pilosicoli isolated from cases of diarrhea in swine in the State of Rio Grande do Sul, Brazil, using an one-day-old chick model. The chicken inoculated with live bacterial cultures were submitted to euthanasia 21 days later, and the cecum was examined histologically using hematoxylin-eosin, silver staining and immunohistochemistry with a polyclonal antibody anti-Brachyspira pilosicoli. With silver staining and immunohistochemistry, respectively, 21.59% and 70.96% of the chicken showed colonization of the cecal epithelium with B. pilosicoli. Differences in the type of colonization characterized by continuous adhesion, focal adhesion or free bacteria in the intestinal lumen were observed. Immunohistochemistry was more efficient to assess intestinal colonization, because 49.37% more colonized chicken could be detected with silver staining. With three strains, elongated figures inside the cytoplasm of epithelial cecal cells in the inoculated chicken were observed.

• Brachyspira spp Brachyspira pilosicoli spirochetal colitis immunohistochemistry pathogenesis.

Abstract in Portuguese:

Paulovich F.B., Borowski S.M., Driemeier D., Razia L.E., Coutinho T. A., Prates A.B.H., Pescador C., Correa A. & Barcellos D.E.S.N. 2004. [Assessment of the pathogenicity of Brachyspira pilosicoli strains by conventional histopathological techniques and by immunohistochemistry.] Avaliação da patogenicidade de amostras de Brachyspira pilosicoli através de técnicas histopatológicas convencionais e por imuno-histoquímica. Pesquisa Veterinária Brasileira 24(3):144-148. Depto Patologia Clínica Veterinária, Faculdade de Veterinária, UFRGS, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@vortex.ufrgs.br The study assessed differences of pathogenicity among 19 strains of Brachyspira pilosicoli isolated from cases of diarrhea in swine in the State of Rio Grande do Sul, Brazil, using an one-day-old chick model. The chicken inoculated with live bacterial cultures were submitted to euthanasia 21 days later, and the cecum was examined histologically using hematoxylin-eosin, silver staining and immunohistochemistry with a polyclonal antibody anti-Brachyspira pilosicoli. With silver staining and immunohistochemistry, respectively, 21.59% and 70.96% of the chicken showed colonization of the cecal epithelium with B. pilosicoli. Differences in the type of colonization characterized by continuous adhesion, focal adhesion or free bacteria in the intestinal lumen were observed. Immunohistochemistry was more efficient to assess intestinal colonization, because 49.37% more colonized chicken could be detected with silver staining. With three strains, elongated figures inside the cytoplasm of epithelial cecal cells in the inoculated chicken were observed.

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:

ABSTRACT.- Barbosa]. D., Oliveira C. M. C., Tokarnia C. H. & Riet-Correa E 2003. [Comparison of the sensibility of cattle and buffaloes to poisoning by Palicourea marcgravii (Rubiaceae).] Comparação da sensibilidade de bovinos e búfalos à intoxicação por Palicourea marcgravii (Rubiaceae). Pesquisa Veterinária Brasileira 23(4): 167-172. Escola de Medicina Veterinária, Campus Castanhal, Universidade Federal do Pará, Rua Maximino Porpino 1000, Castanhal, PA 68743- 080, Brazil. E-mail: diomedes@ufpa.br In order to verify if buffaloes are more resistant than cattle to poisoning by Palicourea marcgravii, the plant was given per os simultaneously to buffaloes and cattle. Seven buffaloes and three head of cattle were used. Doses of 0.5, 1.0 and 2.0 g/kg did not cause signs of poisoning in buffaloes; but doses of 3.0, 4.0 and 6.0 g/kg caused death. In cattle 0.25 g/kg did not cause symptoms; but 0.5 and 2.0 g/kg were lethal. The influence of exercise on the onset of symptoms, the time which elapsed from the beginning of the administration of the plant to the appearance of symptoms, and the symptoms themselves, were similar in the two animal species. The clinical course was longer in buffaloes; whilst in cattle the period between the onset of severe symptoms and death lasted 9 to 17 minutes; in buffaloes it varied from 10 minutes to 1 hour 28 minutes. It can be concluded, that buffaloes are about six times more resistant than cattle to the toxic action of P. maracgravii. The lower incidence of deaths in buffaloes by poisonous plants in the Amazon region is, at least in part, due the lower sensibility of buffaloes to poisoning by this plant. Another factor responsible for the smaller number of buffaloes which die due to plant poisoning in the Amazon region, is possibly that buffaloes prefer the Jowlands, e.g. temporarily flooded areas, which are the habitat of Arrabidaea bilabiata, the second most important poisonous plant of the Amazon region. This plant is less poisonous than P. marcgravii, and its habitat are the higher not flooded areas. So it would be safer, in order to diminish losses, to breed buffaloes instead of cattle in areas where P. marcgravii occurs. The reason for the greater resistance of buffaloes should be further investigated as a possible prophylactic measure to avoid poisoning by P. marcgravii in cattle. On the other hand, Australian investigators modified genetically the ruminai bacteria Butyrivibrio fibrisolvens by introducing a gene, isolated from a Moraxella sp, which codifies a dehalogenase, capable of hydrolyzing fluoroacetate, the poisonous principle of P. marcgravii. Transferring the genetically modified B. fibrisolvens into the rumen of animal, which consume plants that contain fluoroacetate, would be a viable method to control that poisoning through a ruminal detoxifying process for the toxin. Through preliminary contacts, the director of the consorcium in Australia, responsible for the modification of the bacteria, declared that he is interested to sell the technology to our country, but it would be necessary to know if it is permitted to introduce into Brazil the genetically modified bacteria. If allowed, it would be necessary to perform investigations on the viability and the methodology for using this bacteria to control P. marcgravii poisoning in our country.

• Poisonous plants plant poisoning Palicourea marcgravii Rubiaceae cattle buffaloes prophylaxis Butyrivibrio fibrisolvens genetically modified bactéria Intoxicação por planta Rubiaceae bovinos búfalos profilaxia bactérias geneticamente modificadas.

Abstract in Portuguese:

RESUMO.- Barbosa]. D., Oliveira C. M. C., Tokarnia C. H. & Riet-Correa E 2003. [Comparison of the sensibility of cattle and buffaloes to poisoning by Palicourea marcgravii (Rubiaceae).] Comparação da sensibilidade de bovinos e búfalos à intoxicação por Palicourea marcgravii (Rubiaceae). Pesquisa Veterinária Brasileira 23(4): 167-172. Escola de Medicina Veterinária, Campus Castanhal, Universidade Federal do Pará, Rua Maximino Porpino 1000, Castanhal, PA 68743- 080, Brazil. E-mail: diomedes@ufpa.br O presente estudo foi realizado para verificar se búfalos são mais resistentes do que bovinos à ação tóxica de Palicourea marcgravii, mediante a administração da planta por via oral, simultaneamente, a bovinos e a búfalos. Foram usados sete búfalos e três bovinos. Verificou-se que em búfalos doses de 0,5 g/kg, 1,0 g/kg e 2,0 g/kg não causaram sintomas de intoxicação. As doses de 3,0 g/kg, 4,0 g/kg e 6,0 g/kg causaram a morte dos búfalos. Em bovinos, a dose de 0,25g/kg não causou sinais clínicos de intoxicação, enquanto que doses de 0,5 g/kg e 2,0 g/kg causaram a morte. A influência do exercício sobre o aparecimento dos sintomas, o prazo decorrido desde o começo da administração da planta até o início de sintomas, e os próprios sintomas, foram semelhantes nas duas espécies animais. O curso clínico foi mais longo nos búfalos. Enquanto nos bovinos o período entre o aparecimento dos sintomas graves e a morte foi de 9 a 17 minutos, nos búfalos variou de 10 minutos a 1 hora e 28 minutos. Pode se concluir que os bubalinos são aproximadamente seis vezes mais resistentes do que os bovinos à ação tóxica de P. marcgravii. O menor índice de mortes pela ação de plantas tóxicas na Amazônia em búfalos é, pelo menos em parte, devido à maior resistência do búfalo à intoxicação por essa planta. Outro fator responsável pelo menor número de mortes em búfalos pela intoxicação por plantas, na Amazônia, poderia ser que os búfalos preferem a várzea, que é o habitat de Arrabidaea bilabiata, a segunda planta tóxica mais importante da Amazônia, menos tóxica do que P. marcgravii, e com habitat na terra firme. Em áreas onde ocorre P. marcgravii seria mais prudente, para diminuir os prejuízos, criar búfalos em lugar de bovinos. A causa dessa maior resistência do búfalo merece ser investigada para a eventual elaboração de métodos profiláticos da intoxicação por P. marcgravii em bovinos. Por outro lado, pesquisadores australianos modificaram geneticamente a bactéria ruminal Butyrivibrio fibrisolvens, mediante a introdução de um gene, isolado de Moraxella sp, que codifica uma dehalogenase, capaz de hidro-lizar fluoroacetato. A transferência de B.fibrisolvens geneticamente modificado para o rúmen de animais ingerindo plantas que contêm fluoroacetato, como é o caso de P. marcgravii, seria um método viável para o controle da intoxicação mediante a detoxificação ruminal do princípio ativo. Em contatos preliminares o diretor responsável do consórcio na Austrália responsável pela modificação da bactéria, declarou o interesse em vender a tecnologia ao nosso país, porém seria necessário saber se é possível importar essa bactéria geneticamente modificada no Brasil. Caso positivo, seria indispensável realizar pesquisas sobre a viabilidade e a metodologia para o uso dessa bactéria em nosso meio.