RESUMO
In this review, diagnostic techniques and viral agents involved in enteric diseases affecting turkeys are described. Data from field observations and laboratory researches have been reported in turkey flocks for over 70 years, and several viruses have been identified. After a period of 30 years of inoculation experiments and neutralization studies, adequate visualization of the viruses was achieved using electronic microscopy. During the following years, several studies were then conducted to isolate and classify those viruses using cell-culture, embryo-propagation, serological tests, genome electropherotyping by polyacrylamide gel electrophoresis of double-stranded RNA viruses, and recently, nucleic acid studies. Thus, since the 1990s, the nucleic-acid technology has focused on genomic surveys and on the detection of specific segments of the genome of each virus using the polymerase-chain reaction, resulting in several prevalence studies and phylogenetic analyses of different isolates and proper classification of the viruses.(AU)
Assuntos
Animais , Peru , Coronavirus do Peru/classificação , Enterite Transmissível dos Perus/classificação , Enterite Transmissível dos Perus/diagnóstico , Enterite Transmissível dos Perus/históriaRESUMO
In this review, diagnostic techniques and viral agents involved in enteric diseases affecting turkeys are described. Data from field observations and laboratory researches have been reported in turkey flocks for over 70 years, and several viruses have been identified. After a period of 30 years of inoculation experiments and neutralization studies, adequate visualization of the viruses was achieved using electronic microscopy. During the following years, several studies were then conducted to isolate and classify those viruses using cell-culture, embryo-propagation, serological tests, genome electropherotyping by polyacrylamide gel electrophoresis of double-stranded RNA viruses, and recently, nucleic acid studies. Thus, since the 1990s, the nucleic-acid technology has focused on genomic surveys and on the detection of specific segments of the genome of each virus using the polymerase-chain reaction, resulting in several prevalence studies and phylogenetic analyses of different isolates and proper classification of the viruses.
Assuntos
Animais , Coronavirus do Peru/classificação , Enterite Transmissível dos Perus/classificação , Enterite Transmissível dos Perus/diagnóstico , Enterite Transmissível dos Perus/história , PeruRESUMO
Se describe por primera vez en Colombia la enteritis hemorragica (EH), en pavos de 4 a 11 semanas de edad, mediante estudios macroscopicos, histologicos y de microscopia electronica. Se demostro una enteritis hemorragica severa, y esplenomegalia con inclusiones intranucleares en la mayoria de las celulas de la pulpa blanca esplenica y en algunos mononucleares en el intestino delegado. Las inclusiones son caracteristicas; consisten de un centro eosinofilico, rodeado de cromatina densa y condensada sobre la membrana nuclear y de una estructura muy basofila y densa sobre un polo nuclear que parece corresponder a un nucleolo. Al microscopio electronico se aprecian fases del desarrollo viral, desde un material filamentoso y amorfo hasta la formacion de grandes acumulos de viriones y capsides de 70-80 nm de diametro con morfologia tipica de adenovirus. Los viriones se demostraron facilmente en macerados de bazo fijado en formol, tenidos negativamente con fosfotungstato de potasio; no se visualizaron en el contenido intestinal hemorragico estudiado con el mismo metodo. El estudio de microscopia de luz de bazo e intestino es suficiente para establecer el diagnostico de esta entidad