PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Girardini L.K., Siqueira F.M., Krewer C.C., Krewer C.C., Costa M.M. & Vargas A.C. 2012. Phylogenetic and pathotype analysis of Escherichia coli swine isolates from Southern Brazil. Pesquisa Veterinária Brasileira 32(5):374-378. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: agueda.vargas@gmail.com The current study evaluated the presence of virulence factors by a multiplex PCR technique and then phylogenetically classified the studied strains into groups A, B1, B2 and D, according to Clermont et al. (2000), in 152 intestinal and extraintestinal swine isolates of Escherichia coli. Seventy seven isolates tested were positive for virulence factors. Phylogenetic characterization placed 21 samples into group A, 65 into B1, 19 into B2 and 47 into D. Fourteen urine samples were classified as uropathogenic E. coli (UPEC), nine were both UPEC and enterotoxigenic E. coli (ETEC) and four were ETEC only. The most common phylogenetic classifications were B1 and D groups. Of the analyzed fecal samples, 25 were classified as ETEC. Phylogenetically, the group of higher occurrence was B1, followed by B2, A and D. For the small intestine samples, 20 were classified as ETEC. Phylogenetic analysis found groups B1 and A to be the most commons in these samples. Six isolated tissue samples were classified as ETEC and most of them were designated as group D by phylogenetic classification. The phylogenetic analysis could be employed in veterinary laboratories in the E. coli isolates screening, including the possibility of vaccine strain selection and epidemiological searches.

• Escherichia coli uropathogenic E. coli enterotoxigenic E. coli E. coli uropatogênica E. coli enterotoxigênica

Abstract in Portuguese:

RESUMO.- Girardini L.K., Siqueira F.M., Krewer C.C., Krewer C.C., Costa M.M. & Vargas A.C. 2012. Phylogenetic and pathotype analysis of Escherichia coli swine isolates from Southern Brazil. [Análise filogenética e de patotipos de Escherichia coli isoladas de suínos no Sul do Brazil.] Pesquisa Veterinária Brasileira 32(5):374-378. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: agueda.vargas@gmail.com O presente estudo teve por objetivo avaliar a presença de diferentes fatores de virulência em 152 isolados de Escherichia coli intestinais e extra-intestinais provenientes de suínos pela técnica de PCR multiplex e classificá-los nos grupos filogenéticos A, B1, B2 e D, de acordo com Clermont et al. (2000). Setenta e sete isolados foram positivos para pelo menos um fator de virulência. Através da caracterização filogenética, 21 isolados foram caracterizados como pertencentes ao grupo A, 65 ao grupo B1, 19 ao grupo B2 e 47 isolados ao grupo D. Quatorze isolados de urina foram caracterizados como E. coli uropatogênica (UPEC); nove apresentaram fatores de UPEC e E. coli enterotoxigênica (ETEC) simultaneamente e quatro foram classificados como ETEC. Na classificação filogenética, os isolados provenientes de amostras de urina classificaram-se principalmente nos grupos D e B1. Das amostras de fezes analisadas, 25 demonstraram fatores de virulência característicos do patotipo ETEC. Filogeneticamente, o grupo de maior ocorrência foi o B1 seguido de B2, A e D. Em relação às cepas isoladas de intestino delgado, 20 foram caracterizadas como ETEC. Pela filogenia, 23 isolados classificaram-se nos grupos A ou B1. Seis isolados de tecidos foram qualificados como ETEC e a maioria deles foram designados como pertencentes ao grupo D, pela classificação filogenética. A análise filogenética pode ser empregada em laboratórios de diagnóstico veterinário como um screening para isolados de E. coli, incluindo a possibilidade de seleção de cepas vacinais e levantamentos epidemiológicos.

Abstract in English:

ABSTRACT.- Barros M.R., Silveira W.D., Araújo J.M., Costa E.P., Oliveira A.A.F., Santos A.P.S.F., Silva V.A.S. & Mota R.A. 2012. [Antimicrobial resistance and plasmidial profile of Escherichia coli strain isolated from broilers and commercial layers in the state of Pernambuco, Brazil.] Resistência antimicrobiana e perfil plasmidial de Escherichia coli isolada de frangos de corte e poedeiras comerciais no estado de Pernambuco. Pesquisa Veterinária Brasileira 32(5):405-410.Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Av. Dom Manuel de Medeiros s/n, Recife, PE 52171-900, Brazil. E-mail: rinaldo.mota@hotmail.com Although exist poultry non-pathogenic Escherichia coli strains, many others have capacity to impose serious damages to this birds, being able to cause different infectious diseases. Pathogenic strains are termed Avian pathogenic Escherichia coli (APEC) strains. APEC strains harbor chromossomal and plasmid pathogenicity-related genes. The presence of resistance plasmids in avian E. coli strains could facilitate horizontal tranfer of virulence gene between pathogenic and non pathogenic strains. The aim of this paper was to determine the resistance level to 13 different antibacterial drugs of avian E. coli strains (35) isolated from commercial poultry of Pernambuco State, Brazil, and to correlate the detected resistance level to the presence of plasmids. The results show that 94.28% of strains were resistant to at least three different antibacterial drugs with the highest percentage to lincomycin. The Minimal Inibitory Concentration (MIC) showed that multi- resistance to various antibacterial drugs was present in these strains. Plasmids of several sizes, including plasmids of approximately 88Mda were detected in most of the studied strains. The results herein obtained suggest that the high resistance level observed could be due to the presence of plasmids, what could facilitate the transfer of pathogenicity related genes among pathogenic and non pathogenic strains; it is necessary to take a constant survey on the resistance level to antimicrobial drugs of avian E. coli strains to reach a better control of APEC strains and avoid transfer of pathogenicity related genes between strains.

• Escherichia coli plasmid plasmídio

Abstract in Portuguese:

RESUMO.- Barros M.R., Silveira W.D., Araújo J.M., Costa E.P., Oliveira A.A.F., Santos A.P.S.F., Silva V.A.S. & Mota R.A. 2012. [Antimicrobial resistance and plasmidial profile of Escherichia coli strain isolated from broilers and commercial layers in the state of Pernambuco, Brazil.] Resistência antimicrobiana e perfil plasmidial de Escherichia coli isolada de frangos de corte e poedeiras comerciais no estado de Pernambuco. Pesquisa Veterinária Brasileira 32(5):405-410.Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Av. Dom Manuel de Medeiros s/n, Recife, PE 52171-900, Brazil. E-mail: rinaldo.mota@hotmail.com Embora existam linhagens de Escherichia coli não patogênicas para aves, muitas outras possuem a capacidade de causar sérios danos à saúde das mesmas, sendo capazes de ocasionar diferentes tipos de processos infecciosos. As linhagens patogênicas são denominadas Avian Pathogenic Escherichia coli (APEC), possuindo genes relacionados ao processo de patogênese em epissomos (plasmídios) ou no cromossomo. A presença de plasmídios, contendo genes de resistência a antibióticos em linhagens aviárias, patogênicas ou não, indicam a possibilidade de transferência gênica lateral entre diferentes tipos de linhagens facilitando também a transferência de genes de patogenicidade ou virulência. Objetivou-se com este estudo avaliar o perfil de sensibilidade a antibióticos (13) de diferentes amostras (35) de E. coli isoladas de aves comerciais do Estado de Pernambuco apresentando, ou não, sinais clínicos de processos infecciosos e correlacionar esta resistência com a presença de plasmídios. Os testes utilizados demonstraram que 94,28% dos isolados foram resistentes a três ou mais antibióticos, com a lincomicina apresentando o maior percentual de resistência (100%). Na Concentração Inibitória Mínima (CIM) observou-se multirresistência a vários antimicrobianos. A presença de plasmídios foi detecada em 80,0% (28/35) dos isolados, com 16 isolados apresentando plasmídios com peso molecular aproximado de 88 MDa. Também foi verificada a presença de linhagens apresentando plasmídios de vários tamanhos. Concluiu-se que isolados de E. coli resistentes a antimicrobianos utilizados na avicultura estão presentes no Estado de Pernambuco, tanto em frangos de corte quanto em poedeiras comerciais. A presença de plasmídios detectados na maioria dos isolados pode estar associada à resistência aos antimicrobianos e sugere a presença de possíveis genes relacionados à patogenicidade. Monitorar a resistência a antibióticos em bactérias isoladas de animais torna-se um fator determinante para eleição e êxito do tratamento, bem como a possibilidade de eliminação daquelas que possuem plasmídios para se evitar a transferência de genes relacionados à patogenicidade.

Abstract in English:

ABSTRACT.- Knöbl T., Saidenberg A.B.S., Moreno A.M., Gomes T.A.T., Vieira M.A.M., Leite D.S., Blanco J.E. & Ferreira A.J.P. 2011. Serogroups and virulence genes of Escherichia coli isolated from psittacine birds. Pesquisa Veterinária Brasileira 31(10):916-921. Faculdade de Medicina Veterinária do Complexo Educacional FMU, Av. Santo Amaro 1239, São Paulo, SP 04505 002, Brazil. E-mail: tknobl@usp.br Escherichia coli isolates from 24 sick psittacine birds were serogrouped and investigated for the presence of genes encoding the following virulence factors: attaching and effacing (eae), enteropathogenic E. coli EAF plasmid (EAF), pili associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin (afa), capsule K1 (neu), curli (crl, csgA), temperature-sensitive hemagglutinin (tsh), enteroaggregative heat-stable enterotoxin-1 (astA), heat-stable enterotoxin -1 heat labile (LT) and heat stable (STa and STb) enterotoxins, Shiga-like toxins (stx1 and stx2), cytotoxic necrotizing factor 1 (cnf1), haemolysin (hly), aerobactin production (iuc) and serum resistance (iss). The results showed that the isolates belonged to 12 serogroups: O7; O15; O21; O23; O54; O64; O76; O84; O88; O128; O152 and O166. The virulence genes found were: crl in all isolates, pap in 10 isolates, iss in seven isolates, csgA in five isolates, iuc and tsh in three isolates and eae in two isolates. The combination of virulence genes revealed 11 different genotypic patterns. All strains were negative for genes encoding for EAF, EAEC, K1, sfa, afa, hly, cnf, LT, STa, STb, stx1 and stx2. Our findings showed that some E. coli isolated from psittacine birds present the same virulence factors as avian pathogenic E. coli (APEC), uropathogenic E. coli (UPEC) and Enteropathogenic E. coli (EPEC) pathotypes.

• Escherichia coli

Abstract in Portuguese:

RESUMO.- Knöbl T., Saidenberg A.B.S., Moreno A.M., Gomes T.A.T., Vieira M.A.M., Leite D.S., Blanco J.E. & Ferreira A.J.P. 2011. Serogroups and virulence genes of Escherichia coli isolated from psittacine birds. [Sorogrupos e genes de virulência em Escherichia coli isoladas de psitacídeos.] Pesquisa Veterinária Brasileira 31(10):916-921. Faculdade de Medicina Veterinária do Complexo Educacional FMU, Av. Santo Amaro 1239, São Paulo, SP 04505 002, Brazil. E-mail: tknobl@usp.br Amostras de Escherichia coli isoladas de 24 psitacídeos doentes foram sorogrupadas e investigadas para a presença de genes que codificam os seguintes fatores de virulência: attaching e effacing (eae), plasmídeo EAF (EAF), pili associado à pielonefrite (pap), fímbria S (sfa), adesina afimbrial (afa), cápsula K1 (neu), curli (crl, csgA), hemaglutinina termosensível (tsh), enterotoxina termo-estável 1 de E. coli enteroagregativa (astA), toxina termolábil (LT) e toxina termoestável (STa e STb), Shiga-like toxinas (stx1 e stx2), fator citotóxico necrotizante 1 (cnf1), hemolisina (hly), produção de aerobactina (iuc) e resistência sérica (iss). Os resultados mostraram que os isolados pertenciam a 12 sorogrupos: O7; O15; O21; O23; O54; O64; O76; O84; O88; O128; O152 e O166. Os genes de virulência encontrados foram: crl em todos os isolados, pap em 10 isolados, iss em sete isolados, csgA em cinco isolados, iuc e tsh em três isolados e eae em dois isolados. A combinação dos genes de virulência revelou 11 perfis genotípicos distintos. Todas as amostras foram negativas para os genes que codificam EAF, EAEC, K1, sfa, afa, hly, cnf, LT, STa, STb, stx1 e stx2. Estes resultados demonstraram que algumas amostras de E. coli isoladas de psitacídeos apresentam os mesmos fatores de virulência presentes nos patotipos de E. coli patogênicas para aves (APEC), uropatogênicas (UPEC) e E. coli enteropatogênicas (EPEC).

Abstract in English:

ABSTRACT.- Abreu D.L.C., Franco R.M., Nascimento E.R., Pereira V.L.A., Alves F.M.X. & Almeida J.F. 2010. [Profile of antimicrobial resistance and detection of iss gene by the polymerase chain reaction in the typification of pathogenic Escherichia coli in meat type quails under sanitary inspection.] Perfil de sensibilidade antimicrobiana e detecção do gene iss pela reação em cadeia da polimerase na tipificação de Escherichia coli patogênica em codornas de corte sob inspeção sanitária. Pesquisa Veterinária Brasileira 30(5):406-410. Departamento de Tecnologia de Alimentos, Universidade Federal Fluminense, Niterói, RJ 24320-340, Brazil. E-mail: dayseabreu@predialnet.com.br The pathogenicity of Escherichia coli strains is partially related to the expression of virulence factors genes, present in genetic elements called plasmids. APEC strains responsible for diseases in birds may present the iss gene which increases the resistance of E. coli strains to the lityc effect of the host’s serum, besides resistance to several antimicrobials. This study was conduced in order to detect E. coli in tracheae of meat-type quails and to evaluate, by the presence of the iss gene and the profile of antimicrobial susceptibility, the pathogenic potential of the isolated samples for birds and humans. One hundred and eighty tracheae of quails were collected for detection of E. coli, antimicrobial sensitivity tests, and for polymerase chain reaction (PCR), for detection of iss gene. From the examined quails, 8.9 % (16/180) were positive for E. coli, from which 20 strains of this bacterium were obtained. Most of them were resistant to Tetracycline (16/20), followed by Ceftadizime (13/20) and Nalidixic-acid (12/20) and only one isolate was resistant to Amoxicillin. The detection of iss gene occurred in 55% (11/20) of the isolates, indicating that these strains had the potential to be pathogenic not only for quails, but also for other kinds of birds, other animals and even human beings that would be in contact with these E. coli isolates.

• Escherichia coli gene iss

Abstract in Portuguese:

RESUMO.- Abreu D.L.C., Franco R.M., Nascimento E.R., Pereira V.L.A., Alves F.M.X. & Almeida J.F. 2010. [Profile of antimicrobial resistance and detection of iss gene by the polymerase chain reaction in the typification of pathogenic Escherichia coli in meat type quails under sanitary inspection.] Perfil de sensibilidade antimicrobiana e detecção do gene iss pela reação em cadeia da polimerase na tipificação de Escherichia coli patogênica em codornas de corte sob inspeção sanitária. Pesquisa Veterinária Brasileira 30(5):406-410. Departamento de Tecnologia de Alimentos, Universidade Federal Fluminense, Niterói, RJ 24320-340, Brazil. E-mail: dayseabreu@predialnet.com.br A patogenicidade das cepas de Escherichia coli está relacionada à expressão de fatores de virulência encontrados em elementos genéticos denominados plasmídios. O patotipo APEC, responsável por diferentes tipos de doenças em aves, pode apresentar o gene iss que aumenta a resistência das cepas de E. coli aos efeitos líticos do soro, além da resistência a diversos antimicrobianos. Este estudo foi conduzido para detectar E. coli em traquéias de codornas destinadas ao abate e avaliar, pela presença do gene iss e o perfil de susceptibilidade antimicrobiana, o potencial patogênico para aves e humanos dos isolados obtidos. Foram coletadas 180 traquéias de codornas para detecção de E. coli, determinação do perfil de resistência a agentes antimicrobianos e posterior detecção, por reação em cadeia da polimerase (PCR), do gene iss. Das traquéias analisadas, 8,9 % (16/180) foram positivas para E. coli, sendo obtidos 20 isolados deste agente. A maioria dos isolados foi resistente à Tetraciclina (16/20), seguida pela Ceftazidima (13/20) e Ácido Nalidíxico (12/20), sendo apenas um resistente à Amoxicilina. A detecção do gene iss ocorreu em 55% (11/20) dos isolados. A presença do gene iss e a resistência a múltiplos antimicrobianos dos isolados obtidos neste estudo pode indicar um possível potencial patogênico das cepas de E. coli tanto para codornas quanto para outros tipos de aves e animais e mesmo para o ser humano que fique em contato com as mesmas.

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.

• APEC avian Escherichia coli virulence factors

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.

Abstract in English:

ABSTRACT.- Rangel P. & Marin J.M. 2009. Analysis of Escherichia coli isolated from bovine mastitic milk. Pesquisa Veterinária Brasileira 29(5):363-368. Departamento de Morfologia, Estomatologia e Fisiologia, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Avenida do Café s/n, Campus USP, Ribeirão Preto, SP 14040-904, Brazil. E-mail: jmmarin@forp.usp.br Mastitis has been recognized for some time as the most costly disease in dairy herds. From February to November 2004, 670 samples of bovine mastitic milk from which 231 Escherichia coli strains were isolated, were collected from two Brazilian states. The strains were screened for the presence of Shiga toxin-producing (stx 1 and stx 2) and intimin (eae) genes. Twenty (8.6%) strains were detected by PCR to harbor the Shiga toxin genes (8 the stx 1 gene, 12 the stx 2 gene and none both of them). Two (0.8%) of the Escherichia coli strains studied were eae positive non Shiga toxin-producing. The strains were also examined for resistance to 12 antimicrobial agents. The predominantly observed resistance was to tetracycline (92.2%), streptomycin (90.4%), nalidixic acid (88.3%), amikacin (86.5%) and cephalothin (84.8%). Multidrug resistance was found among 152 isolates (65.8%).

• Escherichia coli mastitis antimicrobial agents multidrug resistance eae gene mastite agentes antimicrobianos resistência a antimicrobianos gene eae.

Abstract in Portuguese:

ABSTRACT.- Rangel P. & Marin J.M. 2009. Analysis of Escherichia coli isolated from bovine mastitic milk. Pesquisa Veterinária Brasileira 29(5):363-368. Departamento de Morfologia, Estomatologia e Fisiologia, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Avenida do Café s/n, Campus USP, Ribeirão Preto, SP 14040-904, Brazil. E-mail: jmmarin@forp.usp.br Mastitis has been recognized for some time as the most costly disease in dairy herds. From February to November 2004, 670 samples of bovine mastitic milk from which 231 Escherichia coli strains were isolated, were collected from two Brazilian states. The strains were screened for the presence of Shiga toxin-producing (stx 1 and stx 2) and intimin (eae) genes. Twenty (8.6%) strains were detected by PCR to harbor the Shiga toxin genes (8 the stx 1 gene, 12 the stx 2 gene and none both of them). Two (0.8%) of the Escherichia coli strains studied were eae positive non Shiga toxin-producing. The strains were also examined for resistance to 12 antimicrobial agents. The predominantly observed resistance was to tetracycline (92.2%), streptomycin (90.4%), nalidixic acid (88.3%), amikacin (86.5%) and cephalothin (84.8%). Multidrug resistance was found among 152 isolates (65.8%).

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.

• APEC clonal analysis fliC gene

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.

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.

• Avian colibacillosis Escherichia coli APEC virulence related-genes pathogenic clones

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.

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.- 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.