PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Bezerra F.S.B., Garcia H.A., Alves H.M., Oliveira I.R.S., Silva A.E., Teixeira M.M.G. & Batista J.S. 2008. [Trypanosoma vivax in testicular and epidydimal tissues of experimentally infected sheep.] Trypanosoma vivax nos tecidos testicular e epididimário de ovinos experimentalmente infectados. Pesquisa Veterinária Brasileira 28(12):575-582. Laboratório de Patologia Veterinária, Departamento de Ciências Animais, Universidade Federal Rural do Semi-árido, BR 110 Km 47, Cx. Postal 147, Mossoró, RN 59625-900, Brazil. E-mail: jaelsbatista@hotmail.com Four adult sheep (number 1, 2, 3 and 4), all males, were inoculated intravenously with 1ml of blood containing 1.25x105 trypomastigotes of Trypanosoma vivax, and Sheep 5, 6, 7 and 8 were used as control. After infection, clinical exams considering rectal temperature, respiratory and cardiac frequencies, and parasitaemia were recorded daily for a 30-day experiment period. Blood samples were obtained for 5-day intervals to hematocrit analysis. At the end of the experimental period, the sheep were orquiectomized. Testes and epididymides from these animals were studied anatomopathologically. Samples from these tissues of Sheep 1, 4 and 5 were taken to polymerase chain reaction (PCR). Clinical parameters remained for the infected group above the values observed in the control group during the experimental period. Parasitaemia was observed on day 3 post-infection, and the highest values occurred between day 6 and 10, and day 15 and 18 post-infection. Sheep 1 and 4 showed severe anemia on day 25 post-infection. All sheep of the infected group showed flabby and palid testes. Histologically, moderate to severe testicular degeneration, multifocal epididymitis and hyperplasia of epididymal epithelium were observed. The result of T. vivax PCR analysis in the testes and epididymal tissues was positive in 100% of the samples of the experimentally infected sheep. Epididymal and testicular lesions associated with the presence of the parasite in these tissues, shown by PCR, suggest the participation of T. vivax in the pathophysiological mechanism of reproductive damage.

• rypanosomosis small ruminant PCR anatomopathology testicular degene-ration epididymitis extravascular foci

Abstract in Portuguese:

ABSTRACT.- Bezerra F.S.B., Garcia H.A., Alves H.M., Oliveira I.R.S., Silva A.E., Teixeira M.M.G. & Batista J.S. 2008. [Trypanosoma vivax in testicular and epidydimal tissues of experimentally infected sheep.] Trypanosoma vivax nos tecidos testicular e epididimário de ovinos experimentalmente infectados. Pesquisa Veterinária Brasileira 28(12):575-582. Laboratório de Patologia Veterinária, Departamento de Ciências Animais, Universidade Federal Rural do Semi-árido, BR 110 Km 47, Cx. Postal 147, Mossoró, RN 59625-900, Brazil. E-mail: jaelsbatista@hotmail.com Four adult sheep (number 1, 2, 3 and 4), all males, were inoculated intravenously with 1ml of blood containing 1.25x105 trypomastigotes of Trypanosoma vivax, and Sheep 5, 6, 7 and 8 were used as control. After infection, clinical exams considering rectal temperature, respiratory and cardiac frequencies, and parasitaemia were recorded daily for a 30-day experiment period. Blood samples were obtained for 5-day intervals to hematocrit analysis. At the end of the experimental period, the sheep were orquiectomized. Testes and epididymides from these animals were studied anatomopathologically. Samples from these tissues of Sheep 1, 4 and 5 were taken to polymerase chain reaction (PCR). Clinical parameters remained for the infected group above the values observed in the control group during the experimental period. Parasitaemia was observed on day 3 post-infection, and the highest values occurred between day 6 and 10, and day 15 and 18 post-infection. Sheep 1 and 4 showed severe anemia on day 25 post-infection. All sheep of the infected group showed flabby and palid testes. Histologically, moderate to severe testicular degeneration, multifocal epididymitis and hyperplasia of epididymal epithelium were observed. The result of T. vivax PCR analysis in the testes and epididymal tissues was positive in 100% of the samples of the experimentally infected sheep. Epididymal and testicular lesions associated with the presence of the parasite in these tissues, shown by PCR, suggest the participation of T. vivax in the pathophysiological mechanism of reproductive damage.

Abstract in English:

ABSTRACT.- Abreu S.R.O., Mota R.A., Rosinha G.M.S., Forner O., Pinheiro Júnior J.W., Pereira R.R.B., Castro R.S., Elisei C., Soares C.S., Araújo F.R. & Madureira R.C. 2008. [Genotypic comparison between Corynebacterium pseudotuberculosis samples obtained from sheep and goats with caseous lymphadenitis, raised in the semi-arid region of Pernambuco.] Comparação genotípica de isolados de Corynebacterium pseudotuberculosis de caprinos e ovinos do sertão de Pernambuco. Pesquisa Veterinária Brasileira 28(10):481-487. Clínica Escola de Medicina Veterinária, Faculdade de Ciências Biológicas e da Saúde, Centro de Ensino Superior de Maceió, Rodovia Divaldo Suruagy s/n, Quadra 4, Lote 4, Praia do Francês, Marechal Deodoro, AL 57160-000, Brazil. E-mail: silviobiotec@yahoo.com.br The objective was to genotypically compare 35 samples of Corynebacterium pseudotuberculosis obtained from abscesses of sheep and goats diagnosed with caseous lymphadenitis originated from 5 different municipalities in the semi-arid region of Pernambuco, Brazil. The RFLP-PCR technique with Hpy-Ch4 and Msp I and Pst I Msp I restriction enzimes was used to fingerprint the genes rpoB and pld, respectively. The results demonstrate that there was no difference on the fragments banding pattern among samples, independently of the host species or geographic area studied, defining a homogeneous profile of C. pseudotuberculosis responsible for superficial abscesses for the region.

• Genotyping RFLP-PCR Corynebacterium pseudotuberculosis goats sheep

Abstract in Portuguese:

ABSTRACT.- Abreu S.R.O., Mota R.A., Rosinha G.M.S., Forner O., Pinheiro Júnior J.W., Pereira R.R.B., Castro R.S., Elisei C., Soares C.S., Araújo F.R. & Madureira R.C. 2008. [Genotypic comparison between Corynebacterium pseudotuberculosis samples obtained from sheep and goats with caseous lymphadenitis, raised in the semi-arid region of Pernambuco.] Comparação genotípica de isolados de Corynebacterium pseudotuberculosis de caprinos e ovinos do sertão de Pernambuco. Pesquisa Veterinária Brasileira 28(10):481-487. Clínica Escola de Medicina Veterinária, Faculdade de Ciências Biológicas e da Saúde, Centro de Ensino Superior de Maceió, Rodovia Divaldo Suruagy s/n, Quadra 4, Lote 4, Praia do Francês, Marechal Deodoro, AL 57160-000, Brazil. E-mail: silviobiotec@yahoo.com.br The objective was to genotypically compare 35 samples of Corynebacterium pseudotuberculosis obtained from abscesses of sheep and goats diagnosed with caseous lymphadenitis originated from 5 different municipalities in the semi-arid region of Pernambuco, Brazil. The RFLP-PCR technique with Hpy-Ch4 and Msp I and Pst I Msp I restriction enzimes was used to fingerprint the genes rpoB and pld, respectively. The results demonstrate that there was no difference on the fragments banding pattern among samples, independently of the host species or geographic area studied, defining a homogeneous profile of C. pseudotuberculosis responsible for superficial abscesses for the region.

Abstract in English:

ABSTRACT.- Rocha A.C.G.P., Rocha S.L.S., Lima-Rosa C.A.V., Souza G.F., Moraes H.L.S., Salle F.O., Moraes L.B. & Salle C.T.P. 2008. Genes associated with pathogenicity of avian Escherichia coli (APEC) isolated from respiratory cases of poultry. Pesquisa Veterinária Brasileira 28(3):183-186. Centro de Diagnóstico e Pesquisa em Patologia Aviária, Departamento de Medicina Animal, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 8824, Porto Alegre, RS 91540-000, Brazil. E-mail: ana.crocha@terra.com.br The virulence mechanisms of avian pathogenic Escherichia coli (APEC) have been continually studied and are believed to be multi-factorial. Certain properties are primarily associated with virulent samples and have been identified in avian isolates. In this study a total of 61 E. coli, isolates from chicken flocks with respiratory symptomatology, were probed by Polimerase Chain Reation (PCR) for the presence of genes responsible for the adhesion capacity, P fimbria (papC) e F11 fimbria (felA), colicin production (cvaC), aerobactin presence (iutA), serum resistance (iss), temperature-sensitive hemagglutinin (tsh), and presence of K1 and K5 capsular antigens (kpsII). The iss gene was detected in 73,8%, tsh in 55,7%, iutA in 45,9%, felA in 39,3%, papC in 24,3%, cvaC in 23% and kpsII in18%.

• Escherichia coli virulence PCR poultry pathogenicity

Abstract in Portuguese:

ABSTRACT.- Rocha A.C.G.P., Rocha S.L.S., Lima-Rosa C.A.V., Souza G.F., Moraes H.L.S., Salle F.O., Moraes L.B. & Salle C.T.P. 2008. Genes associated with pathogenicity of avian Escherichia coli (APEC) isolated from respiratory cases of poultry. Pesquisa Veterinária Brasileira 28(3):183-186. Centro de Diagnóstico e Pesquisa em Patologia Aviária, Departamento de Medicina Animal, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 8824, Porto Alegre, RS 91540-000, Brazil. E-mail: ana.crocha@terra.com.br The virulence mechanisms of avian pathogenic Escherichia coli (APEC) have been continually studied and are believed to be multi-factorial. Certain properties are primarily associated with virulent samples and have been identified in avian isolates. In this study a total of 61 E. coli, isolates from chicken flocks with respiratory symptomatology, were probed by Polimerase Chain Reation (PCR) for the presence of genes responsible for the adhesion capacity, P fimbria (papC) e F11 fimbria (felA), colicin production (cvaC), aerobactin presence (iutA), serum resistance (iss), temperature-sensitive hemagglutinin (tsh), and presence of K1 and K5 capsular antigens (kpsII). The iss gene was detected in 73,8%, tsh in 55,7%, iutA in 45,9%, felA in 39,3%, papC in 24,3%, cvaC in 23% and kpsII in18%.

Abstract in English:

ABSTRACT.- Montassier M.F.S., Brentano L., Montassier H.J. & Richtzenhain L.J. 2008. Genetic grouping of avian infectious bronchitis virus isolated in Brazil, based on RT-PCR/RFLP analysis of the S1 gene. Pesquisa Veterinária Brasileira 28(3):190-194. Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando de Paiva 87, São Paulo, SP 05508-000, Brazil. E-mail: leonardo@usp.br Twelve Brazilian isolates and one reference vaccine strain of avian infectious bronchitis virus (IBV) were propagated in embryonating chicken eggs. The entire S1 glycoprotein gene of these viruses was analysed by reverse-transcriptase-polymerase chain reaction and restriction fragment length polymorphism (RT-PCR-RFLP), using the restriction enzymes HaeIII, XcmI and BstyI. The RFLP patterns led to the classification of these isolates into five distinct genotypes: A, B, C, D and Massachusetts. Five of twelve isolates were grouped in Massachusetts genotype and the remaining seven viruses were classified into four distinct genotypes: A (2), B (2), C (2) or D (1). Such genotyping classification agreed with previous immunological analysis for most of these viruses, highlighting the occurrence of a relevant variability among the IBV strains that are circulating in Brazilian commercial poultry flocks.

• Avian infectious bronchitis virus spike glycoprotein genotyping and RFLP

Abstract in Portuguese:

ABSTRACT.- Montassier M.F.S., Brentano L., Montassier H.J. & Richtzenhain L.J. 2008. Genetic grouping of avian infectious bronchitis virus isolated in Brazil, based on RT-PCR/RFLP analysis of the S1 gene. Pesquisa Veterinária Brasileira 28(3):190-194. Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando de Paiva 87, São Paulo, SP 05508-000, Brazil. E-mail: leonardo@usp.br Twelve Brazilian isolates and one reference vaccine strain of avian infectious bronchitis virus (IBV) were propagated in embryonating chicken eggs. The entire S1 glycoprotein gene of these viruses was analysed by reverse-transcriptase-polymerase chain reaction and restriction fragment length polymorphism (RT-PCR-RFLP), using the restriction enzymes HaeIII, XcmI and BstyI. The RFLP patterns led to the classification of these isolates into five distinct genotypes: A, B, C, D and Massachusetts. Five of twelve isolates were grouped in Massachusetts genotype and the remaining seven viruses were classified into four distinct genotypes: A (2), B (2), C (2) or D (1). Such genotyping classification agreed with previous immunological analysis for most of these viruses, highlighting the occurrence of a relevant variability among the IBV strains that are circulating in Brazilian commercial poultry flocks.

Abstract in English:

ABSTRACT.- Gava D., Zanella E.L., Morés N. & Ciacci-Zanella J.R. 2008. Transmission of porcine circovirus 2 (PCV2) by semen and viral distribution in different piglet tissues. Pesquisa Veterinária Brasileira 28(1):70-76. Laboratório de Virologia, Embrapa Suínos e Aves, BR 153 Km 110, Vila Tamanduá, Cx. Postal 21, Concórdia, SC 89700-000, Brazil. E-mail: janice@cnpsa.embrapa.br Porcine circovirus infections are caused by the porcine circovirus 2 (PCV2). Among six different clinical manifestations involving respiratory, enteric, nervous and reproductive signs, the postweaning multisystemic wasting syndrome (PMWS) is the most important and studied disease. However, reproductive failures associated with PCV2 have been increasingly reported. Some studies have shown the possible contamination of sows by semen of PCV2 positive boars. In order to investigate the transmission of PCV2 by contaminated semen and its ability to infect the sow and piglets, 20 PCV2 negative sows were inseminated, 10 with negative boar semen and 10 with previously nested-PCR tested positive boar semen. The sows were weekly monitored and blood samples were collected. Based on the results, 4 out 20 sows were selected (1 sow was PCR negative and inseminated with a negative semen, 2 sows were PCR negative and inseminated with a positive semen and 1 sow was PCR negative and inseminated with a positive semen, but became PCR positive around the 30 days of pregnancy). After weaning, 12 male piglets, 3 of each sow, were selected and maintained under isolation. In order to investigate which organs harbored the virus, the young pigs were necropsied around 9 months of age. Samples of serum collected monthly were tested by immunocitochemistry (ICC), and all 12 pigs serum converted. Samples of lymphoid, systemic and reproductive organs were analyzed by nested-PCR and immunohistochemistry (IHC). Evaluation of the samples by nested-PCR, revealed that several tissues were positive in 10 of 12 pigs, mainly the lymph nodes, bone marrow and spleen. Various samples were positive by IHC in 8 of 12 piglets, being the lymph nodes, tonsils and bulbourethral glands the most frequently positive. Thus, the results of testing different samples, in the 3 tests (ICC, nested-PCR and IHC) were complementary. These results show that PCV2 transmission through semen to the sows and piglets may occur and may also represent a potential risk for the herd.

• Swine PCV2 semen transmission immunohistochemistry PCR

Abstract in Portuguese:

ABSTRACT.- Gava D., Zanella E.L., Morés N. & Ciacci-Zanella J.R. 2008. Transmission of porcine circovirus 2 (PCV2) by semen and viral distribution in different piglet tissues. Pesquisa Veterinária Brasileira 28(1):70-76. Laboratório de Virologia, Embrapa Suínos e Aves, BR 153 Km 110, Vila Tamanduá, Cx. Postal 21, Concórdia, SC 89700-000, Brazil. E-mail: janice@cnpsa.embrapa.br Porcine circovirus infections are caused by the porcine circovirus 2 (PCV2). Among six different clinical manifestations involving respiratory, enteric, nervous and reproductive signs, the postweaning multisystemic wasting syndrome (PMWS) is the most important and studied disease. However, reproductive failures associated with PCV2 have been increasingly reported. Some studies have shown the possible contamination of sows by semen of PCV2 positive boars. In order to investigate the transmission of PCV2 by contaminated semen and its ability to infect the sow and piglets, 20 PCV2 negative sows were inseminated, 10 with negative boar semen and 10 with previously nested-PCR tested positive boar semen. The sows were weekly monitored and blood samples were collected. Based on the results, 4 out 20 sows were selected (1 sow was PCR negative and inseminated with a negative semen, 2 sows were PCR negative and inseminated with a positive semen and 1 sow was PCR negative and inseminated with a positive semen, but became PCR positive around the 30 days of pregnancy). After weaning, 12 male piglets, 3 of each sow, were selected and maintained under isolation. In order to investigate which organs harbored the virus, the young pigs were necropsied around 9 months of age. Samples of serum collected monthly were tested by immunocitochemistry (ICC), and all 12 pigs serum converted. Samples of lymphoid, systemic and reproductive organs were analyzed by nested-PCR and immunohistochemistry (IHC). Evaluation of the samples by nested-PCR, revealed that several tissues were positive in 10 of 12 pigs, mainly the lymph nodes, bone marrow and spleen. Various samples were positive by IHC in 8 of 12 piglets, being the lymph nodes, tonsils and bulbourethral glands the most frequently positive. Thus, the results of testing different samples, in the 3 tests (ICC, nested-PCR and IHC) were complementary. These results show that PCV2 transmission through semen to the sows and piglets may occur and may also represent a potential risk for the herd.

Abstract in English:

ABSTRACT.- Moura A.B., Costa A.J., Jordão Filho S., Paim B.B., Pinto F.R. & Di Mauro D.C. 2007. Toxoplasma gondii in semen of experimentally infected swine. Pesquisa Veterinária Brasileira 27(10):430-434. Centro de Pesquisas em Sanidade Animal, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Jaboticabal, SP 14884-900, Brazil. E-mail: a2abm@cav.udesc.br Eight reproductive boars were divided into three groups and inoculated with Toxoplasma gondii [GI (n=3) 1.5x104 oocysts strain P; GII (n=3) 1.0x106 tachyzoites strain RH; and GIII (n=2) non-inoculated control]. Clinical, hematological, parasitemia and serological tests and studies of the parasite in the semen through bioassay and PCR, and in reproductive organs (Bioassay and immunohistochemical analyses) were conducted to evaluate the toxoplasmic infection. Blood and semen were collected on day -2, -1, 1, 3, 5, 7, 9, 11, 14 and weekly up to 84 days post-inoculation (DPI). No clinical or hematimetric alteration was observed in the boars. Parasitemia was detected in one boar inoculated with oocysts at the 7th DPI and in another boar infected with tachyzoites (GII) at the 3rd and 49th DPI. Serological tests revealed antibodies against T. gondii in animals inoculated with oocysts or tachyzoites at the 7th DPI with dilutions of 1:256 and 1:64, which reached peaks of 1:4096 at day 11 and 9, respectively. The bioassays revealed the presence of the parasite in semen samples of a boar inoculated with oocysts (GI) at 3, 49 and 56 DPI and from two boars infected with tachyzoites (GII), one animal at 5 and two animals at 49 days DPI. Mice inoculated with semen from the control group (GIII) remained serologically negative. PCR analysis showed T. gondii DNA in the semen of Boar 1 and Boar 3 inoculated with tachyzoites and oocysts, respectively. The immuno-histochemical tests showed T. gondii in the reproductive organs of Boar 1 and Boar 2, inoculated with tachyzoites and oocysts, respectively. These findings suggest the possible occurrence of venereal transmission of T. gondii in swine.

• Toxoplasmosis swine semen PCR bioassays

Abstract in Portuguese:

ABSTRACT.- Moura A.B., Costa A.J., Jordão Filho S., Paim B.B., Pinto F.R. & Di Mauro D.C. 2007. Toxoplasma gondii in semen of experimentally infected swine. Pesquisa Veterinária Brasileira 27(10):430-434. Centro de Pesquisas em Sanidade Animal, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Jaboticabal, SP 14884-900, Brazil. E-mail: a2abm@cav.udesc.br Eight reproductive boars were divided into three groups and inoculated with Toxoplasma gondii [GI (n=3) 1.5x104 oocysts strain P; GII (n=3) 1.0x106 tachyzoites strain RH; and GIII (n=2) non-inoculated control]. Clinical, hematological, parasitemia and serological tests and studies of the parasite in the semen through bioassay and PCR, and in reproductive organs (Bioassay and immunohistochemical analyses) were conducted to evaluate the toxoplasmic infection. Blood and semen were collected on day -2, -1, 1, 3, 5, 7, 9, 11, 14 and weekly up to 84 days post-inoculation (DPI). No clinical or hematimetric alteration was observed in the boars. Parasitemia was detected in one boar inoculated with oocysts at the 7th DPI and in another boar infected with tachyzoites (GII) at the 3rd and 49th DPI. Serological tests revealed antibodies against T. gondii in animals inoculated with oocysts or tachyzoites at the 7th DPI with dilutions of 1:256 and 1:64, which reached peaks of 1:4096 at day 11 and 9, respectively. The bioassays revealed the presence of the parasite in semen samples of a boar inoculated with oocysts (GI) at 3, 49 and 56 DPI and from two boars infected with tachyzoites (GII), one animal at 5 and two animals at 49 days DPI. Mice inoculated with semen from the control group (GIII) remained serologically negative. PCR analysis showed T. gondii DNA in the semen of Boar 1 and Boar 3 inoculated with tachyzoites and oocysts, respectively. The immuno-histochemical tests showed T. gondii in the reproductive organs of Boar 1 and Boar 2, inoculated with tachyzoites and oocysts, respectively. These findings suggest the possible occurrence of venereal transmission of T. gondii in swine.

Abstract in English:

ABSTRACT.- Sanz M.G., Venturini L., Assis R.A., Uzal F., Risso M.A., Idiart J.R. & Perfumo C.J. 2007. Fibrinonecrotic enteritis of piglets in a commercial farm: a postmortem study of the prevalence and the role of lesion associated agents Isospora suis and Clostridium perfringens. Pesquisa Veterinária Brasileira 27(7):297-300. Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, CC 296, B1900 AVW, 60 y 119, La Plata, Argentina. E-mail: cjperfumo@fcv.unlp.edu.ar The objectives were to determine the prevalence of fibrinonecrotic enteritis (FNE) on a farrow-to-finish farm of 1,000 sows, to categorize the pathological changes, and to to investigate the lesion associated agents Isospora suis and Clostridium perfringens. Causes of preweaning mortality (PWM) were classified into 8 categories including FNE. Obtained data were evaluated for statistical significance by adjusted Chi-square analysis. Samples of FNE were taken for complementary studies including a PCR technique for genotyping toxin genes of Clostridium perfringens from gut samples fixed in 10% neutral formalin. From 3,153 piglets examined, less than 1% was classified as FNE. FNE prevalence increased progressively from the first to the third week, the last differing statistically from the others. Eighty percent of gut samples with FNE lesions were positive to Isospora suis, when examined by PCR from 9 severe FNE lesions detected 7 positive samples only for a toxin gene, characteristic of C. perfringens type-A.

• Fibrinonecrotic enteritis piglets prevalence Isospora suis Clostridium perfringens PCR

Abstract in Portuguese:

ABSTRACT.- Sanz M.G., Venturini L., Assis R.A., Uzal F., Risso M.A., Idiart J.R. & Perfumo C.J. 2007. Fibrinonecrotic enteritis of piglets in a commercial farm: a postmortem study of the prevalence and the role of lesion associated agents Isospora suis and Clostridium perfringens. Pesquisa Veterinária Brasileira 27(7):297-300. Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, CC 296, B1900 AVW, 60 y 119, La Plata, Argentina. E-mail: cjperfumo@fcv.unlp.edu.ar The objectives were to determine the prevalence of fibrinonecrotic enteritis (FNE) on a farrow-to-finish farm of 1,000 sows, to categorize the pathological changes, and to to investigate the lesion associated agents Isospora suis and Clostridium perfringens. Causes of preweaning mortality (PWM) were classified into 8 categories including FNE. Obtained data were evaluated for statistical significance by adjusted Chi-square analysis. Samples of FNE were taken for complementary studies including a PCR technique for genotyping toxin genes of Clostridium perfringens from gut samples fixed in 10% neutral formalin. From 3,153 piglets examined, less than 1% was classified as FNE. FNE prevalence increased progressively from the first to the third week, the last differing statistically from the others. Eighty percent of gut samples with FNE lesions were positive to Isospora suis, when examined by PCR from 9 severe FNE lesions detected 7 positive samples only for a toxin gene, characteristic of C. perfringens type-A.

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.- Brocchi M., Ferreira A., Lancellotti M., Stehling E.G., Campos T.A., Nakazato G., Pestana de Castro A.F. & Silveira W.D. 2006. Typing of avian pathogenic Escherichia coli strains by REP-PCR. Pesquisa Veterinária Brasileira 26(2):69-73. Departamento de Microbiologia e Imunologia, Instituto de Biologia, Universidade de Campinas, Cx. Postal 6109, Campinas, SP 13081-862, Brazil. E-mail: wds@unicamp.br In the present study the repetitive extragenic palindromic (REP) polymerase chain reaction (PCR) technique was used to establish the clonal variability of 49 avian Escherichia coli (APEC) strains isolated from different outbreak cases of septicemia (n=24), swollen head syndrome (n=14) and omphalitis (n=11). Thirty commensal strains isolated from poultry with no signs of these illnesses were used as control strains. The purified DNA of these strains produced electrophoretic profiles ranging from 0 to 15 bands with molecular sizes varying from 100 bp to 6.1 kb, allowing the grouping of the 79 strains into a dendrogram containing 49 REP-types. Although REP-PCR showed good discriminating power it was not able to group the strains either into specific pathogenic classes or to differentiate between pathogenic and non-pathogenic strains. On the contrary, we recently demonstrated that other techniques such as ERIC-PCR and isoenzyme profiles are appropriate to discriminate between commensal and APEC strains and also to group these strains into specific pathogenic classes. In conclusion, REP-PCR seems to be a technique neither efficient nor universal for APEC strains discrimination. However, the population clonal structure obtained with the use of REP-PCR must not be ignored particularly if one takes into account that the APEC pathogenic mechanisms are not completely understood yet.

• Avian Escherichia coli typing REP-PCR.

Abstract in Portuguese:

Abstract.- Brocchi M., Ferreira A., Lancellotti M., Stehling E.G., Campos T.A., Nakazato G., Pestana de Castro A.F. & Silveira W.D. 2006. Typing of avian pathogenic Escherichia coli strains by REP-PCR. Pesquisa Veterinária Brasileira 26(2):69-73. Departamento de Microbiologia e Imunologia, Instituto de Biologia, Universidade de Campinas, Cx. Postal 6109, Campinas, SP 13081-862, Brazil. E-mail: wds@unicamp.br In the present study the repetitive extragenic palindromic (REP) polymerase chain reaction (PCR) technique was used to establish the clonal variability of 49 avian Escherichia coli (APEC) strains isolated from different outbreak cases of septicemia (n=24), swollen head syndrome (n=14) and omphalitis (n=11). Thirty commensal strains isolated from poultry with no signs of these illnesses were used as control strains. The purified DNA of these strains produced electrophoretic profiles ranging from 0 to 15 bands with molecular sizes varying from 100 bp to 6.1 kb, allowing the grouping of the 79 strains into a dendrogram containing 49 REP-types. Although REP-PCR showed good discriminating power it was not able to group the strains either into specific pathogenic classes or to differentiate between pathogenic and non-pathogenic strains. On the contrary, we recently demonstrated that other techniques such as ERIC-PCR and isoenzyme profiles are appropriate to discriminate between commensal and APEC strains and also to group these strains into specific pathogenic classes. In conclusion, REP-PCR seems to be a technique neither efficient nor universal for APEC strains discrimination. However, the population clonal structure obtained with the use of REP-PCR must not be ignored particularly if one takes into account that the APEC pathogenic mechanisms are not completely understood yet.

Abstract in English:

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

• Chicken anemia virus CAV molecular diagnosis nested-PCR.

Abstract in Portuguese:

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