RESUMO

Background: Bursa of Fabricius (BF) and the thymus are primary lymphoid organs of poultry and play a major role in avian immunity. Enteric system is also involved in immunity. Several pathologic conditions directly impact BF and thymus size, and also affect intestinal parameters. Besides, there are several immune system depressor agents which affect birds. The selection of glucocorticoid as inducer of immunosuppression is applied in many experiments; however there are few studies that are applied to the reality in the field. In this context, the aim of this study was to evaluate the effects of dexamethasone as an inducer of immunosuppression on lymphoid organs and microscopic structures of the jejunum.Materials, Methods & Results: One-day-old chicks were used as a control group (n = 8) and the treated group (n = 25) received intramuscular dexamethasone on 21, 23, 24 and 26 day-old. Control birds and treated birds were euthanized 8, 16, 24, 32 and 40 h after inoculation; four control birds and six treated birds were euthanized on the eighth day after the last inoculation. Thymus, BF and jejunum were collected during the necropsy. The selected organs were processed, stained with hematoxylin and eosin and photographed. The BF and thymus cuts were evaluated by three histopathologists to determine the depletion score. Ten villi of each jejunum were evaluated for width and length of villi, depth crypt, microvillus length, enterocyte length of each villus, and wall thickness. Treated birds presented a mean weight lower than control group during all the experiment. The mean weight and the relative weight of the BF and thymus of control birds were significantly higher than treated ones. The lymphocyte depletion in BF and thymus scores differed significantly between groups, being higher in the group challenged with dexamethasone. There were no significant differences between groups for depth of crypt, height of core and height of microvilli.[...](AU)

Assuntos

RESUMO

Background: Bursa of Fabricius (BF) and the thymus are primary lymphoid organs of poultry and play a major role in avian immunity. Enteric system is also involved in immunity. Several pathologic conditions directly impact BF and thymus size, and also affect intestinal parameters. Besides, there are several immune system depressor agents which affect birds. The selection of glucocorticoid as inducer of immunosuppression is applied in many experiments; however there are few studies that are applied to the reality in the field. In this context, the aim of this study was to evaluate the effects of dexamethasone as an inducer of immunosuppression on lymphoid organs and microscopic structures of the jejunum.Materials, Methods & Results: One-day-old chicks were used as a control group (n = 8) and the treated group (n = 25) received intramuscular dexamethasone on 21, 23, 24 and 26 day-old. Control birds and treated birds were euthanized 8, 16, 24, 32 and 40 h after inoculation; four control birds and six treated birds were euthanized on the eighth day after the last inoculation. Thymus, BF and jejunum were collected during the necropsy. The selected organs were processed, stained with hematoxylin and eosin and photographed. The BF and thymus cuts were evaluated by three histopathologists to determine the depletion score. Ten villi of each jejunum were evaluated for width and length of villi, depth crypt, microvillus length, enterocyte length of each villus, and wall thickness. Treated birds presented a mean weight lower than control group during all the experiment. The mean weight and the relative weight of the BF and thymus of control birds were significantly higher than treated ones. The lymphocyte depletion in BF and thymus scores differed significantly between groups, being higher in the group challenged with dexamethasone. There were no significant differences between groups for depth of crypt, height of core and height of microvilli.[...]

Assuntos

RESUMO

Os objetivos deste estudo foram avaliar a eficácia dos desinfetantes cloreto de benzalcônio (QAC) e iodóforo (I) sobre 10 cepas APEC (Escherichia coli patogênica aviária), bem como verificar se a característica alta patogenicidade está associada a uma maior resistência a estes compostos. O método utilizado foi o de diluição através do teste qualitativo de suspensão. As variáveis estudadas foram: concentrações do QAC (300, 150, 75 e 50 ppm) e do I (100, 75, 50 e 25 ppm), tempos de contato (5, 10 e 20 minutos) e temperatura ±20°C. O QAC inativou todos os isolados nas concentrações de 300 e 150 ppm, em todos os tempos de contato, porém a 75 e 50 ppm no tempo de 5 minutos o desinfetante não foi eficaz para uma e quatro amostras, respectivamente. O I a 100 e 75 ppm inativou os isolados em todos os tempos avaliados, mas a 50 ppm um foi resistente e a 25 ppm oito foram resistentes em todos os tempos de exposição. A característica alta patogenicidade não pareceu promover resistência, quando comparado com a cepa padrão. Concluiu-se, nas condições do experimento, que os dois desinfetantes podem ser usados em procedimentos de higiene frente às cepas APEC, apenas levando-se em consideração a concentração de uso e o tempo de contato.

The objectives of this study were to evaluate the effectiveness of the disinfectant benzalkonium chloride (QAC) and iodophor (I) on 10 strains APEC (Escherichia coli pathogenic avian) and verify that the high feature pathogenicity provides protection factor against these compounds. The method used was the dilution by the qualitative suspension test. The variables studied were: the concentrations of QAC (300, 150, 75 and 50 ppm) and I (100, 75, 50 and 25 ppm), contact times (5, 10 and 20 minutes) and room temperature (20°C). The QAC inactivated all strains at concentrations of 300 and 150 ppm at all contact times, but at 75 and 50 ppm in time of 5 minutes was not effective disinfectant for one and four APEC strains, respectively. The I 100 and 75 ppm inactivated isolates in all time periods, but 50 ppm one was tough and 25ppm eight were resistant in all exposure times. The highly pathogenic feature does not appear to promote resistance when compared with the standard strain. It was concluded, under the experimental conditions, the two disinfectants can be used in front of the hygiene procedures APEC strains, only taking into account the use concentration and contact time.

Assuntos

RESUMO

Os objetivos deste estudo foram avaliar a eficácia dos desinfetantes cloreto de benzalcônio (QAC) e iodóforo (I) sobre 10 cepas APEC (Escherichia coli patogênica aviária), bem como verificar se a característica alta patogenicidade está associada a uma maior resistência a estes compostos. O método utilizado foi o de diluição através do teste qualitativo de suspensão. As variáveis estudadas foram: concentrações do QAC (300, 150, 75 e 50 ppm) e do I (100, 75, 50 e 25 ppm), tempos de contato (5, 10 e 20 minutos) e temperatura ±20°C. O QAC inativou todos os isolados nas concentrações de 300 e 150 ppm, em todos os tempos de contato, porém a 75 e 50 ppm no tempo de 5 minutos o desinfetante não foi eficaz para uma e quatro amostras, respectivamente. O I a 100 e 75 ppm inativou os isolados em todos os tempos avaliados, mas a 50 ppm um foi resistente e a 25 ppm oito foram resistentes em todos os tempos de exposição. A característica alta patogenicidade não pareceu promover resistência, quando comparado com a cepa padrão. Concluiu-se, nas condições do experimento, que os dois desinfetantes podem ser usados em procedimentos de higiene frente às cepas APEC, apenas levando-se em consideração a concentração de uso e o tempo de contato.(AU)

The objectives of this study were to evaluate the effectiveness of the disinfectant benzalkonium chloride (QAC) and iodophor (I) on 10 strains APEC (Escherichia coli pathogenic avian) and verify that the high feature pathogenicity provides protection factor against these compounds. The method used was the dilution by the qualitative suspension test. The variables studied were: the concentrations of QAC (300, 150, 75 and 50 ppm) and I (100, 75, 50 and 25 ppm), contact times (5, 10 and 20 minutes) and room temperature (20°C). The QAC inactivated all strains at concentrations of 300 and 150 ppm at all contact times, but at 75 and 50 ppm in time of 5 minutes was not effective disinfectant for one and four APEC strains, respectively. The I 100 and 75 ppm inactivated isolates in all time periods, but 50 ppm one was tough and 25ppm eight were resistant in all exposure times. The highly pathogenic feature does not appear to promote resistance when compared with the standard strain. It was concluded, under the experimental conditions, the two disinfectants can be used in front of the hygiene procedures APEC strains, only taking into account the use concentration and contact time.(AU)

Assuntos

RESUMO

The thymus is a lymphoid organ and usually evaluated for the degree of lymphocyte loss with subjective histological techniques. This study aimed to adapt and to apply of the digital analysis of the lymphoid depletion system (ADDL) in the thymus in order to obtain a more accurate analysis. Glucocorticoid was used to induce immunosuppression in 55 broilers at 21 days of age; other 15 broilers were the control group. After euthanasia of the broilers, postmortem examination was made. Both thymic chains were collected and six lobes were selected for histological examination of the degree of lymphocyte depletion (scores 1 to 5) and for submission to all stages of processing by the ADDL system. The artificial constructed neural networks (ANN) obtained 94.03% of correct classifications. In conclusion, it was possible to adopt objective criteria to evaluate thymic lymphoid depletion with the ADDL system.(AU)

O timo é um órgão linfóide, que é normalmente avaliado para o grau de perda de linfócitos a partir de técnicas histológicas subjetivas. Este trabalho teve como objetivo a adaptação e aplicação do sistema de análise digital de depleção linfóide (ADDL) para o timo, a fim de tornar sua análise mais acurada. Glicocorticóides foram utilizados a fim de induzir imunossupressão em 55 aves de 21 dias de idade. Outras 15 aves formaram o grupo controle. Posteriormente, para cada um dos aves, realizou-se a eutanásia e necropsia. Ambas as cadeias do timo foram coletadas e foram selecionadas seis lóbulos para processamento histológico, análise quanto ao grau de depleção linfocitária (escores de 1-5) e submissão a todas as fases do processamento pelo sistema ADDL. Observou-se que a rede neural artificial (RNA) construída obteve 94,03% de classificações corretas. Em conclusão, foi possível adotar critérios objetivos para avaliar a depleção linfóide tímica utilizando o sistema ADDL.(AU)

Assuntos

RESUMO

The thymus is a lymphoid organ and usually evaluated for the degree of lymphocyte loss with subjective histological techniques. This study aimed to adapt and to apply of the digital analysis of the lymphoid depletion system (ADDL) in the thymus in order to obtain a more accurate analysis. Glucocorticoid was used to induce immunosuppression in 55 broilers at 21 days of age; other 15 broilers were the control group. After euthanasia of the broilers, postmortem examination was made. Both thymic chains were collected and six lobes were selected for histological examination of the degree of lymphocyte depletion (scores 1 to 5) and for submission to all stages of processing by the ADDL system. The artificial constructed neural networks (ANN) obtained 94.03% of correct classifications. In conclusion, it was possible to adopt objective criteria to evaluate thymic lymphoid depletion with the ADDL system.(AU)

O timo é um órgão linfóide, que é normalmente avaliado para o grau de perda de linfócitos a partir de técnicas histológicas subjetivas. Este trabalho teve como objetivo a adaptação e aplicação do sistema de análise digital de depleção linfóide (ADDL) para o timo, a fim de tornar sua análise mais acurada. Glicocorticóides foram utilizados a fim de induzir imunossupressão em 55 aves de 21 dias de idade. Outras 15 aves formaram o grupo controle. Posteriormente, para cada um dos aves, realizou-se a eutanásia e necropsia. Ambas as cadeias do timo foram coletadas e foram selecionadas seis lóbulos para processamento histológico, análise quanto ao grau de depleção linfocitária (escores de 1-5) e submissão a todas as fases do processamento pelo sistema ADDL. Observou-se que a rede neural artificial (RNA) construída obteve 94,03% de classificações corretas. Em conclusão, foi possível adotar critérios objetivos para avaliar a depleção linfóide tímica utilizando o sistema ADDL.(AU)

Assuntos

RESUMO

Background: Avian Pathogenic Escherichia coli is the main agent of colibacillosis, a systemic disease that causes considerable economic losses to the poultry industry. In vivo experiments are used to measure the ability of E. coli to be pathogenic. Generally, these experiments have proposed different criteria for results interpretation and did not take into account the death time. The aim of this study was to propose a new methodology for the classification of E. coli pathogenicity by the establishment of a pathogenicity index based in the lethality, death time and the ability of the strain to cause colibacillosis lesions in challenged animals. Materials, Methods & Results: A total of 293 isolates of E. coli were randomly selected to this study. The strains were isolated from cellulitis lesions, broiler bedding material or respiratory diseases and were previously confirmed through biochemical profile. The bacterial isolates were kept frozen at -20C. The strains were retrieved from stocks and cultured in brain-heart infusion broth overnight at 37C to obtain a final concentration of 109 UFC/mL. A total of 2940 one-dayold chicks from commercial breeding hens were randomly assigned to groups containing 10 animals and each group was subcutaneously inoculated in the abdominal region with 0.1 mL of the standard inoculum solution containing each of the strains. A control group [...](AU)

Assuntos

RESUMO

Background: Avian Pathogenic Escherichia coli is the main agent of colibacillosis, a systemic disease that causes considerable economic losses to the poultry industry. In vivo experiments are used to measure the ability of E. coli to be pathogenic. Generally, these experiments have proposed different criteria for results interpretation and did not take into account the death time. The aim of this study was to propose a new methodology for the classification of E. coli pathogenicity by the establishment of a pathogenicity index based in the lethality, death time and the ability of the strain to cause colibacillosis lesions in challenged animals. Materials, Methods & Results: A total of 293 isolates of E. coli were randomly selected to this study. The strains were isolated from cellulitis lesions, broiler bedding material or respiratory diseases and were previously confirmed through biochemical profile. The bacterial isolates were kept frozen at -20C. The strains were retrieved from stocks and cultured in brain-heart infusion broth overnight at 37C to obtain a final concentration of 109 UFC/mL. A total of 2940 one-dayold chicks from commercial breeding hens were randomly assigned to groups containing 10 animals and each group was subcutaneously inoculated in the abdominal region with 0.1 mL of the standard inoculum solution containing each of the strains. A control group [...]

Assuntos

RESUMO

A Escherichia coli é comumente encontrada na avicultura e muitas vezes sua presença no organismo dos animais e/ou contaminando as camas de aviários não causa estranheza. Por outro lado, a utilização de inteligência artificial, especificamente redes neurais artificiais, está sendo crescentemente empregada como ferramenta para medir relações não lineares entre variáveis. Neste trabalho foram usados os dados disponíveis referentes a 261 amostras da bactéria oriundas de camas de aviários, lesões de celulite e quadros respiratórios de frangos de corte. O diagnóstico laboratorial envolveu o isolamento do agente, a caracterização dos genes associados à virulência, as lesões provocadas pela inoculação em pintos, o Índice de Patogenicidade das amostras e a resistência antimicrobiana a 14 antibióticos que foram as entradas das redes neurais e sete provas bioquímicas as saídas. A principal conclusão deste artigo foi de que as redes neurais foram capazes de realizar a classificação correta do comportamento das amostras com amplitude de 87,80% a 98,37%. A sensibilidade e a especificidade das classificações obtidas variaram de 59,32% a 99,47% e de 80,00% a 98,54%, respectivamente.(AU)

The Escherichia coli is often found in the poultry industry and, many times, its presence in the organism of the animals and/or contaminating the litter of poultry houses dont cause surprise. On the other hand, the use of artificial intelligence, specifically, artificial neural network, is being increasingly used as tool to measure not linear relations between variables. In this work we used available data from 261 samples of the bacterium isolated of poultry litter, lesions of cellulitis and respiratory problems of broilers. The laboratory diagnosis involved the isolation of the agent, the characterization of the genes associates with the virulence, the lesions provoked by the inoculation in day-old-chicks, the Pathogenicity Index of the samples and the antimicrobial resistance against 14 antibiotics. Those variables were the inputs of the neural network and the outputs were seven biochemical tests. The main conclusion of this paper was that the neural network were capable to make correct classification of the biochemical reactions of all the samples with amplitude from 87.80% to 98.37%. The sensitivity and the specificity of the classifications varied from 59.32% to 99.47% and from 80.00% to 98.54%, respectively.(AU)

Assuntos

RESUMO

A Escherichia coli é comumente encontrada na avicultura e muitas vezes sua presença no organismo dos animais e/ou contaminando as camas de aviários não causa estranheza. Por outro lado, a utilização de inteligência artificial, especificamente redes neurais artificiais, está sendo crescentemente empregada como ferramenta para medir relações não lineares entre variáveis. Neste trabalho foram usados os dados disponíveis referentes a 261 amostras da bactéria oriundas de camas de aviários, lesões de celulite e quadros respiratórios de frangos de corte. O diagnóstico laboratorial envolveu o isolamento do agente, a caracterização dos genes associados à virulência, as lesões provocadas pela inoculação em pintos, o Índice de Patogenicidade das amostras e a resistência antimicrobiana a 14 antibióticos que foram as entradas das redes neurais e sete provas bioquímicas as saídas. A principal conclusão deste artigo foi de que as redes neurais foram capazes de realizar a classificação correta do comportamento das amostras com amplitude de 87,80% a 98,37%. A sensibilidade e a especificidade das classificações obtidas variaram de 59,32% a 99,47% e de 80,00% a 98,54%, respectivamente.

The Escherichia coli is often found in the poultry industry and, many times, its presence in the organism of the animals and/or contaminating the litter of poultry houses don’t cause surprise. On the other hand, the use of artificial intelligence, specifically, artificial neural network, is being increasingly used as tool to measure not linear relations between variables. In this work we used available data from 261 samples of the bacterium isolated of poultry litter, lesions of cellulitis and respiratory problems of broilers. The laboratory diagnosis involved the isolation of the agent, the characterization of the genes associates with the virulence, the lesions provoked by the inoculation in day-old-chicks, the Pathogenicity Index of the samples and the antimicrobial resistance against 14 antibiotics. Those variables were the inputs of the neural network and the outputs were seven biochemical tests. The main conclusion of this paper was that the neural network were capable to make correct classification of the biochemical reactions of all the samples with amplitude from 87.80% to 98.37%. The sensitivity and the specificity of the classifications varied from 59.32% to 99.47% and from 80.00% to 98.54%, respectively.

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RESUMO

O propósito deste estudo foi detectar a presença do vírus da laringotraqueíte infecciosa (VLTI) das galinhas em algumas granjas do Brasil. Tecidos da traquéia e suabes foram coletados de 10 lotes de frangos de corte e galinhas de postura com sinais respiratórios. O material foi inoculado em ovos embrionados e as membranas corioalantóides examinadas por histopatologia. Além disso, as amostras foram submetidas à reação em cadeia da polimerase (PCR). Três lotes foram positivos para VLTI por isolamento viral e PCR. Os resultados confirmam a presença do VLTI nas galinhas no Brasil.

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RESUMO

O propósito deste estudo foi detectar a presença do vírus da laringotraqueíte infecciosa (VLTI) das galinhas em algumas granjas do Brasil. Tecidos da traquéia e suabes foram coletados de 10 lotes de frangos de corte e galinhas de postura com sinais respiratórios. O material foi inoculado em ovos embrionados e as membranas corioalantóides examinadas por histopatologia. Além disso, as amostras foram submetidas à reação em cadeia da polimerase (PCR). Três lotes foram positivos para VLTI por isolamento viral e PCR. Os resultados confirmam a presença do VLTI nas galinhas no Brasil. (AU)

A study was carried out in search for evidences of infectious laryngotracheitis virus (ILTV) infections in some Brazilian chicken flocks. Tracheal tissues and swabs were collected from 10 different flocks of layers and broilers displaying respiratory signs of disease. Samples were processes for virus isolation in embryonated eggs and the membranes examined by histopathology. In addition, specimens were examined by polymerase chain reaction (PCR). Three flocks had ILTV positive chickens by virus isolation and PCR. These results confirm the occurrence of ILTV in chickens in Brazil. (AU)

Assuntos