Resultado da pesquisa (5)
Termo utilizado na pesquisa Nakazato G.
#1 - Virulence factors of avian pathogenic Escherichia coli (APEC), p.479-486
Abstract in English:
ABSTRACT.- Nakazato G., Campos T.A., Stehling E.G., Brocchi M. & Silveira W.D. 2009. Virulence factors of avian pathogenic Escherichia coli (APEC). Pesquisa Veterinária Brasileira 29(7):479-486. Departamento de Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Cidade Universitária Zeferino Vaz s/n, Cx. Postal 6109, Barão Geraldo, Campinas, SP 13081-862, Brazil. E-mail: wds@unicamp.br
Avian pathogenic Escherichia coli (APEC) strains cause a great diversity of diseases in birds and are responsible for great economic losses in the avian industry. To date, several studies have been carried out to better understand the APEC pathogenesis for a possible development of tools which could prevent the economics losses caused by these strains. This review discusses the virulence factors described do date to be expressed by these strains and the advances made to understand and identify virulence determinants present in APEC.
Abstract in Portuguese:
RESUMO.- Nakazato G., Campos T.A., Stehling E.G., Brocchi M. & Silveira W.D. 2009. Virulence factors of avian pathogenic Escherichia coli (APEC). [Fatores de virulência de Escherichia coli aviária patogênica (APEC).] Pesquisa Veterinária Brasileira 29(7):479-486. Departamento de Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Cidade Universitária Zeferino Vaz s/n, Cx. Postal 6109, Barão Geraldo, Campinas, SP 13081-862, Brazil. E-mail: wds@unicamp.br
Linhagens de Escherichia coli patogênicas para aves (APEC) causam uma grande diversidade de doenças em aves e são responsáveis por grandes prejuízos na indústria aviária. Nos últimos anos, vários estudos foram realizados para melhor entender a patogênese de linhagens APEC e para desenvolver ferramentas que podem prevenir as perdas econômicas causadas por estas linhagens. Esta revisão discute os fatores de virulência descritos nestas linhagens e os avanços realizados para entender e identificar os determinantes de virulência presentes em APEC.
#2 - Clonal study of avian Escherichia coli strains by fliC conserved-DNA-sequence regions analysis, p.508-514
Abstract in English:
ABSTRACT.- Campos T.A., Nakazato G., Stehling E.G., Brocchi M. & Silveira W.D. 2008. Clonal study of avian Escherichia coli strains by fliC conserved-DNA-sequence regions analysis. Pesquisa Veterinária Brasileira 28(10):508-514. Departamento de Microbiologia e Imunologia, Instituto de Biologia, Cx. Postal 6109, Universidade Estadual de Campinas, Cidade Universitária Zeferino Vaz s/n, Barão Geraldo, Campinas, SP 3081-862, Brazil. *Corresponding author: wds@unicamp.br
The clonal relationship among avian Escherichia coli strains and their genetic proximity with human pathogenic E. coli, Salmonela enterica, Yersinia enterocolitica and Proteus mirabilis, was determined by the DNA sequencing of the conserved 5’ and 3’regions fliC gene (flagellin encoded gene). Among 30 commensal avian E. coli strains and 49 pathogenic avian E. coli strains (APEC), 24 commensal and 39 APEC strains harbored fliC gene with fragments size varying from 670bp to 1,900bp. The comparative analysis of these regions allowed the construction of a dendrogram of similarity possessing two main clusters: one compounded mainly by APEC strains and by H-antigens from human E. coli, and another one compounded by commensal avian E. coli strains, S. enterica, and by other H-antigens from human E. coli. Overall, this work demonstrated that fliC conserved regions may be associated with pathogenic clones of APEC strains, and also shows a great similarity among APEC and H-antigens of E. coli strains isolated from humans. These data, can add evidence that APEC strains can exhibit a zoonotic risk.
Abstract in Portuguese:
ABSTRACT.- Campos T.A., Nakazato G., Stehling E.G., Brocchi M. & Silveira W.D. 2008. Clonal study of avian Escherichia coli strains by fliC conserved-DNA-sequence regions analysis. Pesquisa Veterinária Brasileira 28(10):508-514. Departamento de Microbiologia e Imunologia, Instituto de Biologia, Cx. Postal 6109, Universidade Estadual de Campinas, Cidade Universitária Zeferino Vaz s/n, Barão Geraldo, Campinas, SP 3081-862, Brazil. *Corresponding author: wds@unicamp.br
The clonal relationship among avian Escherichia coli strains and their genetic proximity with human pathogenic E. coli, Salmonela enterica, Yersinia enterocolitica and Proteus mirabilis, was determined by the DNA sequencing of the conserved 5’ and 3’regions fliC gene (flagellin encoded gene). Among 30 commensal avian E. coli strains and 49 pathogenic avian E. coli strains (APEC), 24 commensal and 39 APEC strains harbored fliC gene with fragments size varying from 670bp to 1,900bp. The comparative analysis of these regions allowed the construction of a dendrogram of similarity possessing two main clusters: one compounded mainly by APEC strains and by H-antigens from human E. coli, and another one compounded by commensal avian E. coli strains, S. enterica, and by other H-antigens from human E. coli. Overall, this work demonstrated that fliC conserved regions may be associated with pathogenic clones of APEC strains, and also shows a great similarity among APEC and H-antigens of E. coli strains isolated from humans. These data, can add evidence that APEC strains can exhibit a zoonotic risk.
#3 - Occurrence of virulence-related sequences and phylogenetic analysis of commensal and pathogenic avian Escherichia coli strains (APEC), p.533-540
Abstract in English:
ABSTRACT.- Campos T.A., Lago J.C., Nakazato G., Stehling E.G., Brocchi M., Castro A.F.P. & Silveira W.D. 2008. Occurrence of virulence-related sequences and phylogenetic analysis of commensal and pathogenic avian Escherichia coli strains (APEC). Pesquisa Veterinária Brasileira 28(10):533-540. Departamento de Microbiologia e Immunologia, Instituto de Biologia, Unicamp, Cidade Universitrária Zeferino Vaz s/n, Campinas, SP 13081-862, Brazil. E-mail: wds@unicamp.br
The presence of iron uptake (irp-2, fyuA, sitA, fepC, iucA), adhesion (iha, lpfAO157/O141, lpfAO157/O154, efa, toxB) and invasion (inv, ial-related DNA sequences and assignment to the four main Escherichia coli phylogenetic groups (A, B1, B2 e D) were determined in 30 commensal E. coli strains isolated from healthy chickens and in 49 APEC strains isolated from chickens presenting clinical signs of septicemia (n=24) swollen head syndrome (n=14) and omphalitis (n=11) by PCR. None of the strains presented DNA sequences related to the inv, ial, efa, and toxB genes. DNA sequences related to lpfAO157/O154, iucA, fepC, and irp-2 genes were significantly found among pathogenic strains, where iucA gene was associated with septicemia and swollen head syndrome and fepC and irp-2 genes were associated with swollen head syndrome strains. Phylogenetic typing showed that commensal and omphalitis strains belonged mainly to phylogenetic Group A and swollen head syndrome to phylogenetic Group D. Septicemic strains were assigned in phylogenetic Groups A and D. These data could suggest that clonal lineage of septicemic APEC strains have a multiple ancestor origin; one from a pathogenic bacteria ancestor and other from a non-pathogenic ancestor that evolved by the acquisition of virulence related sequences through horizontal gene transfer. Swollen head syndrome may constitute a pathogenic clonal group. By the other side, omphalitis strains probably constitute a non-pathogenic clonal group, and could cause omphalitis as an opportunistic infection. The sharing of virulence related sequences by human pathogenic E. coli and APEC strains could indicate that APEC strains could be a source of virulence genes to human strains and could represent a zoonotic risk.
Abstract in Portuguese:
ABSTRACT.- Campos T.A., Lago J.C., Nakazato G., Stehling E.G., Brocchi M., Castro A.F.P. & Silveira W.D. 2008. Occurrence of virulence-related sequences and phylogenetic analysis of commensal and pathogenic avian Escherichia coli strains (APEC). Pesquisa Veterinária Brasileira 28(10):533-540. Departamento de Microbiologia e Immunologia, Instituto de Biologia, Unicamp, Cidade Universitrária Zeferino Vaz s/n, Campinas, SP 13081-862, Brazil. E-mail: wds@unicamp.br
The presence of iron uptake (irp-2, fyuA, sitA, fepC, iucA), adhesion (iha, lpfAO157/O141, lpfAO157/O154, efa, toxB) and invasion (inv, ial-related DNA sequences and assignment to the four main Escherichia coli phylogenetic groups (A, B1, B2 e D) were determined in 30 commensal E. coli strains isolated from healthy chickens and in 49 APEC strains isolated from chickens presenting clinical signs of septicemia (n=24) swollen head syndrome (n=14) and omphalitis (n=11) by PCR. None of the strains presented DNA sequences related to the inv, ial, efa, and toxB genes. DNA sequences related to lpfAO157/O154, iucA, fepC, and irp-2 genes were significantly found among pathogenic strains, where iucA gene was associated with septicemia and swollen head syndrome and fepC and irp-2 genes were associated with swollen head syndrome strains. Phylogenetic typing showed that commensal and omphalitis strains belonged mainly to phylogenetic Group A and swollen head syndrome to phylogenetic Group D. Septicemic strains were assigned in phylogenetic Groups A and D. These data could suggest that clonal lineage of septicemic APEC strains have a multiple ancestor origin; one from a pathogenic bacteria ancestor and other from a non-pathogenic ancestor that evolved by the acquisition of virulence related sequences through horizontal gene transfer. Swollen head syndrome may constitute a pathogenic clonal group. By the other side, omphalitis strains probably constitute a non-pathogenic clonal group, and could cause omphalitis as an opportunistic infection. The sharing of virulence related sequences by human pathogenic E. coli and APEC strains could indicate that APEC strains could be a source of virulence genes to human strains and could represent a zoonotic risk.
#4 - Typing of avian pathogenic Escherichia coli strains by REP-PCR
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.
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.
#5 - Serotyping of Streptococcus suis strains isolated from pigs in the States of São Paulo, Minas Gerais e Paraná, Brazil, 22(1):1-5
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.
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.
