Case–control study of pathogens involved in piglet diarrhea

Abstract\ud \ud Background\ud Diarrhea in piglets directly affects commercial swine production. The disease results from the interaction of pathogens with the host immune system and is also affected by management procedures. Several pathogenic agents such as Campylobacter spp., Clostridium perfringens, Escherichia coli, Salmonella spp., group A rotavirus (RV-A), coronaviruses (transmissible gastroenteritis virus; porcine epidemic diarrhea virus), as well as nematode and protozoan parasites, can be associated with disease cases.\ud \ud \ud Results\ud All bacterial, viral, protozoan, and parasitic agents here investigated, with the exception of Salmonella spp. as well as both coronaviruses, were detected in varying proportions\ud in piglet fecal samples, and positive animals were equally distributed between case and control groups. A statistically significant difference between case and control groups was found only for Cystoisospora suis (p = 0.034) and Eimeria spp. (p = 0.047). When co-infections were evaluated, a statistically significant difference was found only for C. perfringens β2 and C. suis (p = 0.014).\ud \ud \ud Conclusions\ud The presence of pathogens in piglets alone does not determine the occurrence of diarrhea episodes. Thus, the indiscriminate use of antibiotic and anthelminthic medication should be re-evaluated. This study also reinforces the importance of laboratory diagnosis and correct interpretation of results as well as the relevance of control and prophylactic measures.This work was supported by São Paulo Research Foundation (FAPESP)\ud (project number 2010/00390-5 and scholarship support 2011/01563-3 and\ud 2011/19666-3)

Case–control study of pathogens involved in piglet diarrhea

Abstract\ud \ud Background\ud Diarrhea in piglets directly affects commercial swine production. The disease results from the interaction of pathogens with the host immune system and is also affected by management procedures. Several pathogenic agents such as Campylobacter spp., Clostridium perfringens, Escherichia coli, Salmonella spp., group A rotavirus (RV-A), coronaviruses (transmissible gastroenteritis virus; porcine epidemic diarrhea virus), as well as nematode and protozoan parasites, can be associated with disease cases.\ud \ud \ud Results\ud All bacterial, viral, protozoan, and parasitic agents here investigated, with the exception of Salmonella spp. as well as both coronaviruses, were detected in varying proportions\ud in piglet fecal samples, and positive animals were equally distributed between case and control groups. A statistically significant difference between case and control groups was found only for Cystoisospora suis (p = 0.034) and Eimeria spp. (p = 0.047). When co-infections were evaluated, a statistically significant difference was found only for C. perfringens β2 and C. suis (p = 0.014).\ud \ud \ud Conclusions\ud The presence of pathogens in piglets alone does not determine the occurrence of diarrhea episodes. Thus, the indiscriminate use of antibiotic and anthelminthic medication should be re-evaluated. This study also reinforces the importance of laboratory diagnosis and correct interpretation of results as well as the relevance of control and prophylactic measures.This work was supported by São Paulo Research Foundation (FAPESP)\ud (project number 2010/00390-5 and scholarship support 2011/01563-3 and\ud 2011/19666-3)

Detection and quantification of Duffy antigen on bovine red blood cell membranes using a polyclonal antibody

As doenças infecciosas e parasitárias causam perdas importantes em vários setores da produção da pecuária mundial. Estima-se que mais de 600 milhões de bovinos de países tropicais e subtropicais estejam expostos à infecção por Babesia sp. gerando grande prejuízo econômico. Os gêneros Babesia e Plasmodium são hemoparasitas pertencentes ao filo Apicomplexa e apresentam características comuns no processo de invasão eritrocitária. A babesiose bovina causada por Babesia bigemina e Babesia bovis apresenta sinais clínicos similares a malária humana causada por Plasmodium vivax e Plasmodium falciparum. A glicoproteína Duffy é a única receptora para o P. vivax em humanos. A maioria dos indivíduos negros africanos é resistente a este parasita devido a uma mutação que provoca a ausência de expressão desta glicoproteína na superfície das hemácias. Tendo em vista este fato, e que animais da subespécie Bos taurus taurus são mais susceptíveis à babesiose quando comparados à animais Bos taurus indicus, objetivou-se neste trabalho a detecção e quantificação do antígeno Duffy na superfície dos eritrócitos de bovinos empregando para tal, anticorpo policlonal que permitisse investigar se as diferenças na susceptibilidade são devido a diferentes níveis de expressão do antígeno Duffy nas hemácias. Ensaios de ELISA mostraram que o anticorpo produzido foi capaz de reconhecer o antígeno Duffy presente nas hemácias bovinas e a análise quantitativa não demonstrou diferença significativa na presença do mesmo. Estes resultados sugerem que a resistência maior dos zebuínos à babesiose não se deve à ausência de expressão, ou à presença em menor quantidade do antígeno Duffy na superfície de suas hemácias.Babesiosis is one of the most important diseases affecting livestock agriculture worldwide. Animals from the subspecies Bos taurus indicus are more resistant to babesiosis than those from Bos taurus taurus. The genera Babesia and Plasmodium are Apicomplexa hemoparasites and share features such as invasion of red blood cells (RBC). The glycoprotein Duffy is the only human erythrocyte receptor for Pasmodium vivax and a mutation which abolishes expression of this glycoprotein on erythrocyte surfaces is responsible for making the majority of people originating from the indigenous populations of West Africa resistant to P. vivax. The current work detected and quantified the Duffy antigen on Bos taurus indicus and Bos taurus taurus erythrocyte surfaces using a polyclonal antibody in order to investigate if differences in susceptibility to Babesia are due to different levels of Duffy antigen expression on the RBCs of these animals, as is known to be the case in human beings for interactions of Plasmodium vivax-Duffy antigen. ELISA tests showed that the antibody that was raised against Duffy antigens detected the presence of Duffy antigen in both subspecies and that the amount of this antigen on those erythrocyte membranes was similar. These results indicate that the greater resistance of B. taurus indicus to babesiosis cannot be explained by the absence or lower expression of Duffy antigen on RBC surfaces.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Diagnóstico da Leishmaniose Visceral Canina pelas técnicas de imunoistoquímica e PCR em tecidos cutâneos em associação com a RIFI e ELISA-teste

O objetivo deste trabalho foi avaliar as técnicas de imunoistoquímica (IMIQ) e de PCR (Reação em Cadeia da Polimerase) em tecidos cutâneos para o diagnóstico da Leishmaniose Visceral Canina (LVC) e compará-los com os exames parasitológicos em tecidos corados histoquimicamente (hematoxilina-eosina, HE) e com testes sorológicos, como a Reação de Imunofluorescência Indireta (RIFI) e ensaio imunoenzimático (ELISA). Dos 34 cães naturalmente infectados, classificados em assintomáticos, oligossintomáticos e polissintomáticos, foram coletadas amostras de pele sadia ou com lesão para a realização da IMIQ, HE e PCR. Não somente peles lesionadas (56,5%), mas também sadias (31,8%) encontravam-se positivas pela IMIQ, confirmadas posteriormente pela PCR em 97,8% das amostras. No grupo assintomático, 87,5% estavam negativos pelos testes sorológicos, mas positivos em 50% dos casos pela IMIQ e 100% pela PCR. Entre os oligossintomáticos, 100%, 85,7% e 28,6% encontravam-se positivos, respectivamente, pela PCR, sorologia e IMIQ. Os cães polissintomáticos eram 91,7% soropositivos e tinham parasitas na pele. em geral, a técnica PCR teve maior positividade (100%). A eficiência dos testes variou de acordo com a evolução da doença, demonstrando a necessidade da associação de técnicas, usando-se IMIQ para confirmação da sorologia e a PCR apenas nos casos suspeitos após a IMIQ. Dessa forma, pode-se aumentar os níveis de positividade e contribuir para o controle desta zoonose.The purpose of the present study was to evaluate the immunohistochemistry (IMHC) and PCR (Polymerase Chain Reaction) tests for Canine Visceral Leishmaniasis (CVL) diagnosis and compare the results with serological tests such as the indirect fluorescence antibody test (IFAT), ELISA and a parasitological test (microscopic direct examination of the parasite stained with haematoxylin and eosin - HE). For this study, samples of healthy or lesion skin tissues were obtained from 34 CVL naturally infected dogs classified in three groups: asymptomatic, oligosymptomatic and polisymptomatic. Not only lesion (56.5%) but also healthy skins (31.8%) were positives by IMHC and confirmed by PCR in 97.8% of skin samples. In asymptomatic group, 87.5% dogs were negatives by serological tests, but positives by IMHC in 50% and by PCR in 100%. In oligosymptomatic group, 100%, 85.7% and 28.6% of dogs were positives, respectively by PCR, serological and IMHC tests. In addition, 91.7% of polisymptomatic dogs were serum positive and had intact parasites in the skin. In general, PCR showed higher positivity (100%). The efficiency of each test varied with the evolution of the disease. IMHC may be used to confirm the results of the serology and PCR in inconclusive cases after HE and IMHC. The association of techniques proposed in this study may increase the positivity and contributed to the control of this canine disease.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Diagnóstico da Leishmaniose Visceral Canina pelas técnicas de imunoistoquímica e PCR em tecidos cutâneos em associação com a RIFI e ELISA-teste Canine Visceral Leishmaniasis diagnosis by immunohistochemistry and PCR in skin tissues in association with RIFI and ELISA-test

O objetivo deste trabalho foi avaliar as técnicas de imunoistoquímica (IMIQ) e de PCR (Reação em Cadeia da Polimerase) em tecidos cutâneos para o diagnóstico da Leishmaniose Visceral Canina (LVC) e compará-los com os exames parasitológicos em tecidos corados histoquimicamente (hematoxilina-eosina, HE) e com testes sorológicos, como a Reação de Imunofluorescência Indireta (RIFI) e ensaio imunoenzimático (ELISA). Dos 34 cães naturalmente infectados, classificados em assintomáticos, oligossintomáticos e polissintomáticos, foram coletadas amostras de pele sadia ou com lesão para a realização da IMIQ, HE e PCR. Não somente peles lesionadas (56,5%), mas também sadias (31,8%) encontravam-se positivas pela IMIQ, confirmadas posteriormente pela PCR em 97,8% das amostras. No grupo assintomático, 87,5% estavam negativos pelos testes sorológicos, mas positivos em 50% dos casos pela IMIQ e 100% pela PCR. Entre os oligossintomáticos, 100%, 85,7% e 28,6% encontravam-se positivos, respectivamente, pela PCR, sorologia e IMIQ. Os cães polissintomáticos eram 91,7% soropositivos e tinham parasitas na pele. Em geral, a técnica PCR teve maior positividade (100%). A eficiência dos testes variou de acordo com a evolução da doença, demonstrando a necessidade da associação de técnicas, usando-se IMIQ para confirmação da sorologia e a PCR apenas nos casos suspeitos após a IMIQ. Dessa forma, pode-se aumentar os níveis de positividade e contribuir para o controle desta zoonose.<br>The purpose of the present study was to evaluate the immunohistochemistry (IMHC) and PCR (Polymerase Chain Reaction) tests for Canine Visceral Leishmaniasis (CVL) diagnosis and compare the results with serological tests such as the indirect fluorescence antibody test (IFAT), ELISA and a parasitological test (microscopic direct examination of the parasite stained with haematoxylin and eosin - HE). For this study, samples of healthy or lesion skin tissues were obtained from 34 CVL naturally infected dogs classified in three groups: asymptomatic, oligosymptomatic and polisymptomatic. Not only lesion (56.5%) but also healthy skins (31.8%) were positives by IMHC and confirmed by PCR in 97.8% of skin samples. In asymptomatic group, 87.5% dogs were negatives by serological tests, but positives by IMHC in 50% and by PCR in 100%. In oligosymptomatic group, 100%, 85.7% and 28.6% of dogs were positives, respectively by PCR, serological and IMHC tests. In addition, 91.7% of polisymptomatic dogs were serum positive and had intact parasites in the skin. In general, PCR showed higher positivity (100%). The efficiency of each test varied with the evolution of the disease. IMHC may be used to confirm the results of the serology and PCR in inconclusive cases after HE and IMHC. The association of techniques proposed in this study may increase the positivity and contributed to the control of this canine disease