PESQUISA VETERINÁRIA BRASILEIRA

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:

ABSTRACT.- Pagnani K.J.R., Pestana de Castro A.F., Gottschalk M., Silveira, W.D. & Nakazato G. 2002. [Serotyping of Streptococcus suis strains isolated from pigs in the States of São Paulo, Minas Gerais e Paraná, Brazil.] Sorotipagem de amostras de Streptococcus suis isolados de suínos em granjas dos Estados de São Paulo, Minas Gerais e Paraná. Pesquisa Veterinária Brasileira 22(1):1-5. Depto Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, SP 13081-970, Brazil. Streptococcus suis infection in swine is common in all countries where hog production is well developed. This infection has been associated with bronchopneumonia, meningitis, arthritis, pericarditis, myocarditis, endocarditis, fibrinous polyserositis, septicaemia, rhinitis, and abortion. Streptococcus suis has also been described as a pathogen for ruminants and humans. In Brazil there are severa! clinical evidences about the existence of S. suis disease in pigs affecting more than 50% of farms in States of São Paulo, Minas Gerais and Paraná. In the present research 51 strains of S. suis isolated from piggeries of the States of São Paulo, Minas Gerais and Paraná were collected from different pathologies such as septicaemia, meningitis, arthritis and pneumonia and been recovered either in pure culture oras the predominant organism from porcine tissues. Culture of specimens was carried out on 5% bovine blood agar plates incubated at 37ºC for 24 hr: For the biochemical identification the a-hemolytic colonies of all capsulated isolates were submitted to various conventional tests, such as hydrolysis of arginine, Voges-Proskauer Test, and production of acid from various carbohydrates (inulin, salicin, trehalose, lactose, sucrose, sorbitol, mannitol and glycerol). The strains were also tested for their ability to grow in the presence of 6,5% NaCI and for the amylase production. In addition strains were tested by Api Strep 20 to confirm the identification of S.suis. For capsular typing only capsulated strains were typed by co-agglutination test, using antisera raised in rabbits against all reference strains from serotypes 1 to 8. Strains belonging to other serotypes were also typed. The co-agglutination was used for serotyping and the capsular reaction test was carried out for mieasuring the potency of the prepared antisera. From the total of 51 examined strains the following results were obtained, with regard to serotyping: 30 (58,8%) were serotype 2, 11 (21,6%) were serotype 3, seven (13, 72%) were serotype 7, two (3,92%) were serotype 1 and one strain belonged to serotype 14 (1,96%). As far as we are concerned, this is the first report on the isolation of a large number of S. suis strains in Brazil, from cases of illness caused by this bacterium among piglets. Also it was carried out serotyping of the isolates, showíng a high prevalence of serotype 2, as compared to other known serotypes of S. suis.

• Streptococcus suis isolation serotyping co-agglutination isolamento sorotipagem co-aglutinação.

Abstract in Portuguese:

RESUMO.- Pagnani K.J.R., Pestana de Castro A.F., Gottschalk M., Silveira, W.D. & Nakazato G. 2002. [Serotyping of Streptococcus suis strains isolated from pigs in the States of São Paulo, Minas Gerais e Paraná, Brazil.] Sorotipagem de amostras de Streptococcus suis isolados de suínos em granjas dos Estados de São Paulo, Minas Gerais e Paraná. Pesquisa Veterinária Brasileira 22(1):1-5. Depto Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, SP 13081-970, Brazil. Infecções causadas por Streptococcus suis são muito comuns em países onde a indústria de carne suína é desenvolvida. Estas infecções estão relacionadas a casos clínicos de broncopneumonia, meningite, artrite, pericardite, miocardite, endocardite, poliserosite fibrinosa, septicemia, rinite e aborto. Esta bactéria também foi descrita como patógeno de ruminantes e humanos. No Brasil há evidências clínicas da existência de processos infecciosos causados por S. suis afetando mais de 50% das granjas em Estados como São Paulo, Minas Gerais e Paraná. No presente estudo foram isoladas 51 amostras de 5. suis de granjas do Estados acima referidos, coletadas de diferentes casos clínicos como septicemia, meningite, artrite e pneumonia, tendo sido obtidas ou em cultura pura ou como patógeno de maior predominância nos tecidos de suínos. Este material foi semeado em Columbia ágar sangue adicionado de 5% de sangue bovino e incubado a 37ºC por 24 horas. Para a identificação bioquímica as colônias que apresentavam a-hemólise, bem como as amostras padrão, foram submetidas a testes convencionais para a confirmação da espécie 5. suis, tais como: hidrólise de arginina, teste de Voges-Proskaue1: e produção de ácido a partir de vários carboidratos (inulina, salicina, trealose, lactose, sacarose, sorbitol, manitol e glicerol). As amostras também foram testadas para habilidade de crescimento em meio de TSA com 6,5% de NaCI e para a produção de amilase. Todas as amostras que fizeram parte desta pesquisa foram testadas pelo sistema Api 20 Strep para confirmação dos resultados obtidos nos testes convencionais. Para a sorotipagem foram produzidos antissoros de 1 a 8. Outras amostras não pertencentes a estes sorotipos também foram sorotipadas. O antissoro produzido em coelhos foi titulado pelo teste de aglutinação em tubo com 2-mercaptoetanol e pelo teste de reação capsular e, quando adequados, foram usados no teste de co-aglutinação, para a sorotipagem das amostras de 5. suis. A sorotipagem das 51 amostras isoladas mostraram os seguintes resultados: 30 (58,8%) foram classificadas corno sorotipo 2, 11 (21,6%) das amostras como sorotipo 3, sete (13,72%) como sorotipo 7, duas (3,92%) como sorotipo 1 e uma amostra como pertencente ao sorotipo 14 (1,96%). Este é o primeiro relato do isolamento de um grande número de amostras de 5. S. suis no Brasil, de casos típicos de processos infecciosos causados por esta bactéria. Também foi realizada a sorotipagem dos isolados, mostrando uma alta prevalência do sorotipo 2, quando comparada com a dos demais sorotipos encontrados.