Resultado da pesquisa (8)

Termo utilizado na pesquisa colibacillosis

#1 - Pathological, microbiological and immunohistochemical characterization of avian colibacillosis in broiler chickens of Mozambique

Abstract in English:

Avian colibacillosis is an acute and globally occurring infectious disease of domestic and wild birds caused by Escherichia coli, and it is associated with considerable economic losses mainly due to the morbidity and mortality associated. The present study aimed to describe the pathological, bacteriological and immunohistochemical aspects of avian colibacillosis in broiler chickens of Mozambique. Forty-nine broiler chicken presented anorexia, decreased weight gain, ataxia, diarrhea, dyspnea, and death in a clinical course of 3-5 days. The birds were raised in five farms (small, medium and large farms) with manual and automatic breeding system, with flocks ranging from 100 to 20,000 birds. At the necropsy, all birds had poor body condition, and the pericardium and the Glisson’s capsule of all avian exhibited different degrees of adherence often associated with severe fibrin deposition. The thoracic and abdominal air sacs were thickened and adhered to the costal wall. Mild, moderate or marked hepatomegaly associated with white pinpoint multifocal areas (100%, 49/49) and mild to moderate splenomegaly in 75.5% (37/49) with a mottled surface were observed. The lungs and kidney were enlarged and reddish. Histologically, a multiorgan fibrinoheterophilic polyserositis was observed in 75.5% of the cases (37/49), which were characterized by inflammatory infiltrates composed mainly of degenerative heterophils, macrophages and plasma cells, associated with fibrin deposits and intermixed by coccobacillary bacterial basophilic aggregates. These affected mainly the pericardium (28.6%, 14/49), the pleura (18.4%, 9/49), the Glisson’s capsule (10.2%, 5/49), the ventriculus (10.2, 5/33), and the proventriculus (8.2%, 4/49) serosa. Multifocal to coalescing areas of coagulative necrosis associated with similar inflammatory cells were observed mainly in the spleen (28.6%, 14/49), liver (24.5%, 12/49), and intestines (22.4%, 11/49). A similar infiltrate was also observed affecting the the lungs (16.3%, 8/49), the kidney (16.3%, 8/49) and the myocardium (14.3%, 7/49). Isolation and identification of E. coli was obtained in 12 cases through bacterial culture. Some organs (2 cases of each farms) were selected and submitted to immunohistochemistry anti-E. coli, and a positive stain was observed in all tested cases in liver (3/3), heart (4/4), spleen (1/1), lungs (4/4), intestines (4/4), bursa of Fabricius (1/1), ventriculus (1/1), and proventriculus (1/1) tissue sections. These results demonstrate that E. coli was the cause of mortality in these birds. Therefore, biosecurity and management measures should be employed to prevent and control the disease occurrence in Mozambique’s poultry farming.

Abstract in Portuguese:

A colibacilose aviária é uma doença aguda de ocorrência mundial que acomete aves domésticas e silvestres, causada por Escherichia coli e resulta em perdas econômicas consideráveis devido à elevada morbidade e mortalidade das aves. O presente estudo teve o objetivo de descrever os aspectos patológicos, bacteriológicos e imuno-histoquímicos de colibacilose aviária em frangos de corte de Moçambique. Um total de 49 frangos de corte apresentaram anorexia, baixo ganho de peso, ataxia, diarreia, dispneia e morte em um curso clínico de 3 a 5 dias. As aves eram provenientes de 5 granjas (pequenas, média e grandes), com sistema de criação manual e automático, com rebanhos que variavam de 100 a 20.000 aves. À necropsia, todas as aves exibiam condição corporal ruim a caquética, além de pericárdio e cápsula de Glisson de todas aves (100%; n=49) com diferentes graus de aderência e deposição de fibrina de forma difusa acentuada. Os sacos aéreos torácicos e abdominais estavam espessados e aderidos à parede costal. Foi observado ainda hepatomegalia discreta, moderada a severa frequentemente associada com áreas multifocais puntiformes brancacentas (100%; 49/49), e esplenomegalia discreta a moderada, associado a áreas multifocais moteadas (75,5%; 37/49). Os pulmões e rins estavam aumentados e com coloração avermelhada. Histologicamente, observou-se majoritariamente serosite fibrinoheterofílica em 75,5% dos casos (37/49), caracterizadas por infiltrado inflamatório composto por heterófilos degenerados, macrófagos, linfócitos e plasmócitos, com deposição de fibrina entremeada por uma miríade de estruturas bacterianas cocobacilares. Esta lesão foi observada principalmente em pericárdio (28,6%; 14/49), pleura (18,4%; 9/49), cápsula de Glisson (10,2%; 5/49), ventrículo (10,2; 5/33) e em proventrículo (8,2%; 4/49). Áreas multifocais a coalescentes de necrose de coagulação associada a infiltrado inflamatório semelhante ao descrito foi observado principalmente no baço (28,6%; 14/49), fígado (24.5%; 12/49), e intestinos (8,2%; 4/49). Um infiltrado inflamatório semelhante também foi visualizado em pulmões (16,3%; 8/49), rins (16,3%; 8/49) e miocárdio (14,3%; 7/49), Colônias puras de E. coli foram identificadas e isoladas em 12 casos. Alguns órgãos (2 de cada granja) foram submetidos ao exame imuno-histoquímico anti-E. coli e marcação positiva foi visualizada em todos casos testados, como em fígado (3/3), coração (4/4), baço (1/1), pulmão (4/4), intestinos (4/4), bursa de Fabricius (1/1), rim (1/1), ventrículo (1/1) e proventrículo (1/1). Estes resultados demonstram que E. coli foi a causa de morte destas aves. Sendo assim, a adoção de boas medidas de biosseguridade e de manejo são indispensáveis para a prevenção e controle da ocorrência da doença nas granjas de frango de corte de Moçambique.


#2 - Phylogenetic characterization of serum plus antibiotic-resistant extraintestinal Escherichia coli obtained from the liver of poultry carcasses in Pernambuco, 37(10):1069-1073

Abstract in English:

ABSTRACT.- Vaz R.V., Gouveia G.V., Andrade N.M.J., Costa M.M. & Lima-Filho J.V. 2017. Phylogenetic characterization of serum plus antibiotic-resistant extraintestinal Escherichia coli obtained from the liver of poultry carcasses in Pernambuco. Pesquisa Veterinária Brasileira 37(10):1069-1073. Departamento de Biologia, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros s/n, Dois Irmãos, Recife, PE 52171-900, Brazil. E-mail: jose.mlimafo@ufrpe.br In this study, avian extraintestinal Escherichia coli obtained from the liver of poultry carcasses approved for human consumption in the State of Pernambuco-Brazil were tested for antibiotic plus serum-resistance. Liver samples (n=110) were obtained from one slaughterhouse and 88 bacterial isolates were identified as Escherichia coli. The antibiotic-resistance profiles of antibiotics used in human and/or veterinary practice were accessed by the disk-diffusion method. Phenotypes with high resistance to streptomycin (84.0%), tetracycline (44.7%), amikacin (29.8%), gentamicin (21.3%) and ciprofloxacin (21.3%) were identified. Resistance to antibiotics such as ceftazidime, amoxicillin-clavulanic acid and imipenem was also recorded. Twenty isolates with distinct antibiotic-resistance and susceptibility profiles were selected for serum resistance assays, phylogenetic characterization and detection of the iss gene. We have shown that multidrug resistant isolates were often simultaneously resistant to broiler and human sera. Phylogenetic characterization of serum- plus antibiotic-resistant isolates have shown three belonging to group D, eleven to group B1, one to group B2, and five to group A. We concluded that commensal E. coli strains isolated from the liver of healthy poultry carcasses can harbor and potentially share multidrug- plus virulence genes found in pathogenic pathotypes. This suspicion was not related to specific phylogenetic groups or presence of the iss gene.

Abstract in Portuguese:

RESUMO.- Vaz R.V., Gouveia G.V., Andrade N.M.J., Costa M.M. & Lima-Filho J.V. 2017. Phylogenetic characterization of serum plus antibiotic-resistant extraintestinal Escherichia coli obtained from the liver of poultry carcasses in Pernambuco. [Caracterização filogenética de Escherichia coli extraintestinal soro- e antibiótico-resistentes isoladas do fígado de carcaças de frango em Pernambuco.] Pesquisa Veterinária Brasileira 37(10):1069-1073. Departamento de Biologia, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros s/n, Dois Irmãos, Recife, PE 52171-900, Brazil. E-mail: jose.mlimafo@ufrpe.br Neste estudo, isolados de Escherichia coli extraintestinal aviária obtidos a partir do fígado de carcaças de aves aprovadas para consumo humano no Estado de Pernambuco-Brasil foram testados para resistência a antibióticos e soro. As amostras de fígado (n = 110) foram obtidas de um abatedouro, sendo 88 isolados bacterianos identificados como Escherichia coli. Os perfis de resistência a antibióticos de uso humano e/ou veterinário foram determinados pelo método de disco-difusão. Foram identificados fenótipos com alta resistência à estreptomicina (84,0%), tetraciclina (44,7%), amicacina (29,8%), gentamicina (21,3%) e ciprofloxacina (21,3%). A resistência a antibióticos utilizados na medicina humana e/ou veterinária, tais como a ceftazidima, amoxicilina-ácido clavulânico, estreptomicina e imipenem também foi registrada. Vinte amostras com perfis distintos de resistência/sensibilidade a antibióticos foram selecionadas para os ensaios de resistência ao soro, caracterização filogenética e detecção do gene iss. Foi demonstrado que isolados resistentes a múltiplas drogas foram também simultaneamente resistentes ao soro de frangos e ao soro humano. A caracterização filogenética desses isolados mostraram três pertencentes ao grupo D, onze ao grupo B1, um ao grupo B2 e cinco ao grupo A. Conclui-se que E. coli comensais isoladas do fígado de carcaças de aves saudáveis podem abrigar e potencialmente compartilhar genes de resistência a drogas e de virulência encontrados em patotipos patogênicos. Essa suspeita não foi relacionada com grupos filogenéticos específicos ou com a presença do gene iss.


#3 - Pathological and bacteriological characterization on broilers totally condemned due to colibacillosis under the control of the Federal Inspection Service, 37(9):949-957

Abstract in English:

ABSTRACT.- Casagrande R.A., Machado G., Guerra P.R., Castro L.A., Spanamberg A., Silva S.C., Cardoso M.R.I. & Driemeier D. 2017. [Pathological and bacteriological characterization on broilers totally condemned due to colibacillosis under the control of the Federal Inspection Service.] Caracterização anatomopatológica e bacteriológica em frangos de corte condenados totalmente por colibacilose sob Serviço de Inspeção Federal. Pesquisa Veterinária Brasileira 37(9):949-957. Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Bairro Agronomia, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br Colibacillosis is the main infectious cause of total carcass condemnation in broilers in southern Brazil. This study aims to determine the degree of agreement between the total carcass condemnation for colibacillosis in broilers slaughtered in establishments under Federal Inspection Service (SIF) with the pathological and bacteriological diagnosis. The study was conducted with 45 broilers totally condemned by colibacillosis (case) and theirs 45 respective controls (chickens without lesions). All broilers condemned had gross lesions and the controls had not. The Kappa-Cohen’s test showed that these two variables had almost perfect agreement. Broilers condemned showed lesions in liver (27/45); liver and air sacs (11/45); liver and heart (2/45); liver, heart and air sacs (2/45); liver, air sacs and oviduct (1/45); liver, air sacs, heart and subcutaneous (1/45); and liver, air sacs, oviduct and spleen (1/45). There is almost perfect agreement between carcass condemnation and liver damage. Histologically, in 41 cases and 12 controls were observed lesions, the most frequent diagnoses were random necrotizing hepatitis, fibrinous-heterophilic bronchitis, acute pericarditis and lymphoplasmacytic tracheitis. In hepatitis cases was isolated Escherichia coli, Enterococcus sp. and Streptococcus sp. (10/38) and in bronchitis or bronchopneumonia E. coli and coagulase positive Staphylococcus (9/14). The polymerse chain reaction (PCR) and immunohistochemistry (IHC) tests for Mycoplasma gallisepticum and M. synoviae were negative. In cases of total carcass condemnation by Colibacillosis the liver was the main organ affected. Therefore, the condemnation criteria should be revised, suggesting conviction for hepatitis in these cases, because other bacteria can cause hepatitis, as demonstrated in this study.

Abstract in Portuguese:

RESUMO.- Casagrande R.A., Machado G., Guerra P.R., Castro L.A., Spanamberg A., Silva S.C., Cardoso M.R.I. & Driemeier D. 2017. [Pathological and bacteriological characterization on broilers totally condemned due to colibacillosis under the control of the Federal Inspection Service.] Caracterização anatomopatológica e bacteriológica em frangos de corte condenados totalmente por colibacilose sob Serviço de Inspeção Federal. Pesquisa Veterinária Brasileira 37(9):949-957. Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Bairro Agronomia, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br A colibacilose é a principal causa infecciosa de condenação total de carcaça em frangos de corte no sul do Brasil. Esse trabalho tem por objetivo determinar o grau de concordância entre a condenação total por colibacilose de frangos de corte abatidos em estabelecimento sob Serviço de Inspeção Federal (SIF) com o diagnóstico anatomopatológico e bacteriológico. O estudo foi realizado com 45 frangos de corte condenados totalmente por colibacilose (caso) e seus respectivos 45 controles (frangos sem lesões). Em todos os frangos condenados pelo SIF havia lesões macroscópicas e, nos controles não se observou. Através do teste Kappa-Cohen´s essas duas variáveis apresentaram concordância quase perfeita. As aves condenadas apresentaram lesões em fígado (27/45); em fígado e sacos aéreos (11/45); em fígado e coração (2/45); fígado, sacos aéreos e coração (2/45); fígado, sacos aéreos e oviduto (1/45); fígado, sacos aéreos, coração e tecido subcutâneo (1/45); e fígado, sacos aéreos, oviduto e baço (1/45). Observou-se concordância quase perfeita entre condenação e lesão hepática. Histologicamente, em 41 casos e 12 controles observaram-se lesões, sendo os mais frequentes hepatite necrosante aleatória, bronquite fibrino-heterofílica, pericardite aguda e traqueíte linfoplasmocitária. Nas aves com hepatite identificou-se E. coli, Enterococcus sp. e Streptococcus sp. (10/38) e, nas aves com bronquite ou broncopneumonia isolou-se Escherichia coli e Staphylococcus coagulase positiva (9/14). O PCR em tempo real e a imuno-histoquímica para Mycoplasma gallisepticum e M. synoviae foram negativos. Nos casos de condenação total por colibacilose o fígado foi o principal órgão acometido, portanto, o critério de condenação deveria ser revisto, sugerindo condenação por hepatite nesses casos, já que outras bactérias podem causar hepatite, como foi demonstrado nesse estudo.


#4 - Pathologic and microbiologic aspects of pet psittacine infected by Escherichia coli and Salmonella Typhimurium, 37(4):379-384

Abstract in English:

ABSTRACT.- Siqueira R.A.S., Maciel W.C., Vasconcelos R.H., Bezerra W.G.A., Lopes E.S., Machado D.N., Lucena M.F. & Lucena R.B. 2017. Pathologic and microbiologic aspects of pet psittacine infected by Escherichia coli and Salmonella Typhimurium. Pesquisa Veterinária Brasileira 37(4):379-384. Laboratório de Estudos Ornitológicos, Universidade Estadual do Ceará, Itaperi, Fortaleza, CE 60740-000, Brazil. Email: raul_spfc15@hotmail.com The role of Escherichia coli in healthy microbiota of psittacine is controversial, and the presence of Salmonella sp. indicates possible disease. Therefore, this study aimed to identify the presence of E. coli and Salmonella spp. in a psittacine pet that died in Fortaleza, Brazil, correlating pathogenicity aspects of the isolates through the evaluation of lesions and antimicrobial susceptibility. Psittacine pets sent to the Laboratory of Ornithological Studies, State University of Ceará, that died in 2014 and 2015 were necropsied. Fragments of liver, kidneys, intestine, lung, heart, spleen and brain were collected for microbiological and histopathological analyses. Scores were attributed to lesions and isolated strains submitted to antimicrobial susceptibility test. From the seventy necropsied birds, nineteen were positive for E. coli and one for Salmonella Typhimurium. Congestive lesions and lymphoplasmocitic inflammatory infiltrate were observed varying from light to moderate and were the main findings. In the analyzed strains, multidrug resistance against different groups of antibiotics was observed. In conclusion, according to the results, E. coli strains and the Salmonella Typhimurium isolate produced significant lesions in the psittacine pets, and multidrug resistance may hinder treatments with antibiotics used in avian pet medicine.

Abstract in Portuguese:

RESUMO.- Siqueira R.A.S., Maciel W.C., Vasconcelos R.H., Bezerra W.G.A., Lopes E.S., Machado D.N., Lucena M.F. & Lucena R.B. 2017. Pathologic and microbiologic aspects of pet psittacine infected by Escherichia coli and Salmonella Typhimurium. [Aspectos patológicos e microbiológicos de Psittaciformes de companhia infectados por Escherichia coli e Salmonella Typhimurium.] Pesquisa Veterinária Brasileira 37(4):379-384. Laboratório de Estudos Ornitológicos, Universidade Estadual do Ceará, Itaperi, Fortaleza, CE 60740-000, Brazil. Email: raul_spfc15@hotmail.com A participação de Escherichia coli na microbiota saudável de Psicittaciformes e a de Salmonella spp. já indica possível doença. O objetivo deste estudo foi pesquisar a presença de E. coli e Salmonella spp. em psittaciformes de companhia na cidade de Fortaleza/Ceará, traçando os aspectos de patogenicidade destas cepas através das lesões e da sensibilidade antimicrobiana. Foram necropsiados os psittaciformes de companhia encaminhados ao Laboratório de Estudos Ornitológicos da Universidade Estadual do Ceará durante o período de 2014 a 2015. No momento da necropsia foram coletados fragmentos de fígado, rins, intestino, pulmão, coração, baço e encéfalo para posterior processamento microbiológico e histopatológico. As lesões foram graduadas e as cepas isoladas submetidas a antibiograma. Das setenta aves necropsiadas, dezenove foram positivas para E. coli e apenas uma para Salmonella Typhimurium. As lesões de congestão e infiltrado inflamatório linfoplasmocitário variaram de leve a moderado, e foram as principais lesões encontradas. Nas cepas analisadas foi constatada multiresistência a diferentes grupos de antibióticos testados. De acordo com os achados, pode-se concluir que os isolados de E. coli e Salmonella Typhimurium produziram lesões significativas em psittaciformes em Fortaleza, Brasil, e a multirresistência pode dificultar o tratamento com antibióticos usados na clínica de aves de companhia.


#5 - 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.


#6 - Desenvolvimento e avaliação de novas estratégias de imunização contra colibacilose suína, p.84-90

Abstract in English:

Simionatto S., Vaz E.K., Michelon A., Seixas F.K., Dellagostin O.A. 2005. [Development and evaluation of new strategies for immunization against swine colibacillosis.] Desenvolvimento e avaliação de novas estratégias de imunização contra colibacilose suína. Pes-quisa Veterinária Brasileira 25(2):84-90. Laboratório de Biologia Molecular, Centro de Bio-tecnologia, UFPel, Campus Capão do Leão, Cx. Postal 354, Pelotas, RS 96010-900, Brazil. E-mail: ssimionatto@bol.com.br Swine colibacillosis caused by enterotoxigenic Escherichia coli remains one of the main sanitary problems in pig farms. The recombinant DNA technology offers the possibility of developing new immunization strategies. This paper describes the development of a subunit vaccine through the expression and purification of the E. coli K88 FaeC fimbrial protein. The gene that codes for this antigen was amplified by PCR and cloned into an E. coli expression vector fused to a 6X histidine tag. The recombinant protein was purified by affinity chromatography and used for mice immunization. In parallel, the same gene was cloned into an eucariotic expression vector with the addition of the Kozak sequence for improving translation of this gene in muscle cells. The resulting plasmid named pUP310 was purified in large scale and used to immunize mice. The immune response afforded by both forms of immunization was monitored by ELISA. There was an immune response in mice inoculated with pUP310 and purified FaeC. It was possible to detect anti-FaeC antibodies 42 days after the first inoculation. The antibody titer increased with time, being still detectable 7 months after the first inoculation. It is concluded that recombinant FaeC and pUP310 are potential tools for immunization of swine against E. coli K88.

Abstract in Portuguese:

Simionatto S., Vaz E.K., Michelon A., Seixas F.K., Dellagostin O.A. 2005. [Development and evaluation of new strategies for immunization against swine colibacillosis.] Desenvolvimento e avaliação de novas estratégias de imunização contra colibacilose suína. Pes-quisa Veterinária Brasileira 25(2):84-90. Laboratório de Biologia Molecular, Centro de Bio-tecnologia, UFPel, Campus Capão do Leão, Cx. Postal 354, Pelotas, RS 96010-900, Brazil. E-mail: ssimionatto@bol.com.br Swine colibacillosis caused by enterotoxigenic Escherichia coli remains one of the main sanitary problems in pig farms. The recombinant DNA technology offers the possibility of developing new immunization strategies. This paper describes the development of a subunit vaccine through the expression and purification of the E. coli K88 FaeC fimbrial protein. The gene that codes for this antigen was amplified by PCR and cloned into an E. coli expression vector fused to a 6X histidine tag. The recombinant protein was purified by affinity chromatography and used for mice immunization. In parallel, the same gene was cloned into an eucariotic expression vector with the addition of the Kozak sequence for improving translation of this gene in muscle cells. The resulting plasmid named pUP310 was purified in large scale and used to immunize mice. The immune response afforded by both forms of immunization was monitored by ELISA. There was an immune response in mice inoculated with pUP310 and purified FaeC. It was possible to detect anti-FaeC antibodies 42 days after the first inoculation. The antibody titer increased with time, being still detectable 7 months after the first inoculation. It is concluded that recombinant FaeC and pUP310 are potential tools for immunization of swine against E. coli K88.


#7 - Experimental reproduction of colibacillosis in piglets

Abstract in English:

Experimental neonatal colibacillosis, in newbom piglets was attempted using 4 groups of enterotoxigenic Escherichia coli (ETEC) strains, as follows: 1) Two strains from serogroup 0149:K91, both producing thermolabile enterotoxin (LT) and K88 colonization factor; 2) Two strains from serogroup 0101:K30, producing thermostable enterotoxin (STa) and K99 colonization factor; 3) One strain from serogroup 0157:K?, producing thermostable enterotoxin of the STb type and K88 antigen, and 4) One strain from serogroup 08:K?, producing STa enterotoxin anda new colonization factor, named F42. All fourteen piglets inoculated orally with these strains of ETEC developed clinical disease and died up to 42 hours after inoculation, being possible to visualize, by indirect fluorescent antibody technique, in all of them, that colonization of small intestine by the inoculated ETEC had occurred. The production of STa "in vivo", into the gut, by strains from group 2 and 4 was an important factor to prove that experimental colibacillosis did occur. In fact, coprocultures either from the diarrheic stools or from the gut contents revealed a high rate of LT+-K88+ and STa+ -K99+ colonies recovery. Though some quantitative differences among the examined materiais have been observed, the recovery of STa + -F42 + colonies was lower than in the former groups of ETEC strains. However clinical symptoms, production of STa "in vivo" and colonization of the gut of inoculated piglets proved that F42 antigen is undoubtedly a new colonization factor among ETEC involved in porcine colibacillosis.

Abstract in Portuguese:

Foi tentada a reprodução experimental da colibacilose suína neonatal, em leitões recém-nascidos, usando-se para tal 4 grupos de amostras de Escherichia coli enterotoxigênicas (ETEC), a saber: 1) Duas amostras do sorogrupo 0149:K81, produtoras da enterotoxina termolábil (L T) e do fator de colonização K88; 2) Duas amostras do sorogrupo 0101:K30, produtoras da enterotoxina termoestável (STa) e do fator de colonização K99; 3) Uma amostra do sorogrupo 0157:K?, produtora da enterotoxina termoestável do tipo STb e do fator de colonização K88, e 4) Uma amostra do sorogrupo 08:K?, produtora da enterotoxina termoestável (STa) e de um novo fator de colonização, denominado F42. Todos os 14 leitões inoculados por via oral com estas amostras de ETEC desenvolveram doença clínica com morte até 42 horas após a inoculação, tendo sido possível detectar em todos eles a colonização do intestino delgado pelas amostras de ETEC inoculadas, através da técnica de imunofluorescência indireta. A produção de STa "in vivo", por amostras dos grupos 2 e 4 foi um fator importante na comprovação de que a reprodução experimental da doença por estas amostras realmente ocorreu. De fato, a coprocultura, quer das fezes diarréicas, quer do conteúdo intestinal dos animais, revelou um alto índice de recuperação de colonias LT+ -K88+ e STa+ -K99+. Embora tenham ocorrido entre os diversos materiais examinados algumas diferenças quantitativas, a recuperação de colônias STa=+ -F42+ foi menor do que nos casos anteriores, porém os achados referentes a doença clínica, produção de STa "in vivo" e colonização do intestino delgado dos leitões inoculados, comprovaram que o antígeno F42 é, sem dúvida, um novo fator de colonização em amostras de ETEC envolvidas na colibacilose suína.


#8 - Virulence factors present in cultures of Escherichia coli isolated from pigs in the region of Concórdia, Santa Catarina, Brazil

Abstract in English:

Four hundred and seventy-seven cultures of Escherichia coli isolated in the region of Concórdia, Santa Catarina, Brazil, were examined for the presence of ''virulence factors", such as: thermolabile (LT) enterotoxin; thermostable (STa and STb) enterotoxins and the colonization factors K88, K99 and 987P. Paired samples of sera from some sick piglets· were also collected for the search of anti-LT antibodies. Eighty-six (18,02%) E. coli cultures produced ·STa enterotoxin whereas LT enterotoxin was detected in 8 (1,67%) only. Among 391 STa- cultures 49 (12,53%) were STb+. Among 28 K88+ cultures, 1 produced LT; 9 STa and the remaining were non-enterotoxigenic. None of the L T+ cultures codified for K99 antigen, which, on the other hand, was found in 5 STa+ and in 17 non-entérotoxigenic cultures. 987P antigen was found in 3 non-enterotoxigenic cultures. Four out of 10 samples of the examined paired sera showed serological conversion in relation to titres found in ·the passive immunehemolysis (PIH) test. The results of serogrouping revealed that all LT+ cultures belonged to serogroup 01.49. Among 86 STa+ cultures, 1 was grouped as serogroup 09, 2 as 010, 4 as 035; 2 as 064; 3 as 0108; 2 as 0138; 1 as 0149 and 1 as 0157. Seventy STa+ cultures were not classified.· Among 49 STb+ cultures 1 belonged to serogroup 09; 4 to 010; 1 to 035; 1 to 0139; 2 to 0149; 1 to 0157 and 39 cultures could not be serogrouped. These results suggest that in porcine colibacillosis of the region of Concórdia, SC, Brasil the thermostable enterotoxins (STa and STb) may play an important role. It could be possible that among these cultures other colonization factors, different from K88, K99 and 987P may occur. Also, most cultures examined could not be grouped among the serogroups generally accepted as enteropathogenic for swine.

Abstract in Portuguese:

Quatrocentos e setenta e sete amostras de Escherichia coli, isoladas na região de Concórdia, SC, Brazil, foram examinadas quanto a presença de fatores de virulência a saber: enterotoxína termolábil (LT), enterotoxinas termoestáveis (STa e STb) e os fatores de colonização K88, K99 e 987P. Amostras pareadas de soro de alguns leitões doentes foram também coletadas para a pesquisa de anticorpos anti-LT. Oitenta e seis (18,02%) amostras de E. coli produziram a enterotoxina STa enquanto a enterotoxina LT-foi detectada em apenas 8 (1.67%). Entre as-381 amostras STa-, 49 (12.53%) foram STb+. Entre 28 amostras K88+, uma produziu LT, 9 STa e as restantes eram não enterotoxigenicas. Nenhuma das amostras ·LT+ codificou para o antígeno K99, porém, este foi encontrado em 5 amostras STa+ e em 17 não entérotoxigênicas. Quatro entre os 10 soros examinados apresentaram conversão sorológica nos níveis de anticorpos anti-LT quando os soros foram examinados pelo teste da imunohemólise passiva (PIH). Os resultados dos exames sorológicos revelaram que todas as amostras LT+ pertenciam ao sorogrupo 0149. Entre 86 amostras STa+, 1 foi classificada como pertencendo ao sorogrupo 09, 2 ao 010; 4 ao 035; 2 ao 064; 3 ao 0108; 2 ao 0138; 1 ao 0149; 1 ao 0157 e 70 amostras não foram Classificadas. Entre as 49 amostras STb+ 1 pertencia ao sorogrupo 09; 4 ao 010; 1 ao 035; 1 ao 0139; 2 ao 0149; 1 ao 0157 e 39 não foram classificadas. Estes resultados sugerem que na colibacilose suína da região· de Concórdia as enterotoxinas termoestáveis (STa e STb) possam desempenhar um importante papel, existindo a possibilidade de que nelas possam ocorrer outros fatores de colonização que não K88, K99 e 987P. As amostras estudadas também, em sua maioria, não se enquadraram entre· aqueles sorogrupos geralmente aceitos como enteropatogênicos para suínos.


Colégio Brasileiro de Patologia Animal SciELO Brasil CAPES CNPQ UNB UFRRJ CFMV