| Revista: | Revista brasileira de ciencia avicola |
| Base de datos: | PERIÓDICA |
| Número de sistema: | 000279316 |
| ISSN: | 1516-635X |
| Autores: | Barreto, Maria Lucia1 Nascimento, Elmiro Rosendo do1 Pereira, V.L.A Nascimento, Maria da Graca Fichel do2 |
| Instituciones: | 1Universidade Federal Fluminense, Faculdade de Veterinaria, Niteroi, Rio de Janeiro. Brasil 2Empresa Brasileira de Pesquisa Agropecuaria, Agroindustria de Alimentos, Rio de Janeiro. Brasil |
| Año: | 2005 |
| Periodo: | Ene-Mar |
| Volumen: | 7 |
| Número: | 1 |
| Paginación: | 1-9 |
| País: | Brasil |
| Idioma: | Inglés |
| Tipo de documento: | Nota breve o noticia |
| Enfoque: | Experimental |
| Resumen en inglés | Avian mycoplasmas occur in a variety of bird species. The most important mycoplasmas for chickens and turkeys are Mycoplasma gallisepticum (MG), M. synoviae (MS), and M. meleagridis. Besides, M. iowe (MI) is an emerging pathogen in turkeys, but of little concern for chickens. Mycoplasmas are bacteria that lack cell wall and belong to the class Mollicutes. Although they have been considered extracellular agents, scientists admit nowadays that some of them are obligatory intracellular microorganisms, whereas all other mycoplasmas are considered facultative intracellular organisms. Their pathogenic mechanism for disease include adherence to host target cells, mediation of apoptosis, innocent bystander damage to host cell due to intimate membrane contact, molecular (antigen) mimicry that may lead to tolerance, and mitotic effect for B and/or T lymphocytes, which could lead to suppressed T-cell function and/or production of cytotoxic T cell, besides mycoplasma by-products, such as hydrogen peroxide and superoxide radicals. Moreover, mycoplasma ability to stimulate macrophages, monocytes, T-helper cells and NK cells, results in the production of substances, such as tumor necrosing factor (TNF-a), interleukin (IL-1, 2, 6) and interferon (a, b, g). The major clinical signs seen in avian mycoplasmosis are coughing, sneezing, snicks, respiratory rales, ocular and nasal discharge, decreased feed intake and egg production, increased mortality, poor hatchability, and, primarily in turkeys, swelling of the infraorbital sinus(es). Nevertheless, chronic and unapparent infections are most common and more threatening. Mycoplasmas are transmitted horizontally, from bird to bird, and vertically, from dam to offspring through the eggs. Losses attributed to mycoplasmosis, mainly MG and MS infections, result from decreased egg production and egg quality, poor hatchability (high rate of embryonic mortality and culling of day-old birds), po |
| Disciplinas: | Medicina veterinaria y zootecnia, Biología |
| Palabras clave: | Aves de corral, Medicina veterinaria, Biología celular, Infecciones, Mycoplasma, Microorganismos, Diagnóstico, Daños |
| Keyword: | Veterinary medicine and animal husbandry, Biology, Poultry, Veterinary medicine, Cell biology, Infections, Mycoplasma, Microorganisms, Diagnosis, Damage |
| Texto completo: | Texto completo (Ver HTML) |
