Pathological, immunohistochemical, and molecular findings in commercial laying hens and in backyard chickens naturally infected with the infectious laryngotracheitis virus
AUTOR(ES)
Preis, IS, Fiúza, ATL, Silva, CC, Braga, JFV, Couto, RM, Martins, NR da S, Ecco, R
FONTE
Rev. Bras. Cienc. Avic.
DATA DE PUBLICAÇÃO
2014-12
RESUMO
Seventy-eight chickens from a very high poultry density (approximately eight million) region and twelve backyard chickens from neighboring areas were analyzed by histopathology and additional techniques for the presence of the infectious laryngotracheitis virus. The virus distribution was determined in different tissues using immunohistochemistry (IHC) and polymerase chain reaction (PCR). The disease was histopathologically diagnosed in 41.0% (32/78) of the commercial layers. Lesions were mainly characterized by syncytial cells with eosinophilic intranuclear inclusion body formed from the hyperplastic epithelium of the upper respiratory tract, primary and secondary bronchi, and conjunctiva. IHC showed 70% (21/30) positive signal in the larynx/trachea and, 53.8% (14/26) in the lungs, either in epithelial cells or syncytia. In the turbinates and paranasal sinuses, 29.6% (8/27) of samples showed positive signal. PCR detected the following gallid herpesvirus 1-positive percentages: conjunctiva 63.2% (31/49), lungs 57.6% (30/52), turbinates and paranasal sinuses 56% (28/50), and larynx/trachea 50% (39/78). IHC showed to be a useful additional tool for definitive ILT diagnosis, especially during the subacute phase of the disease when syncytial cells with intranuclear inclusion bodies are no longer observed. PCR using specific primers from ICP4 gene, generating a product of 237 base pairs, was sensitive for ILT diagnosis, and very useful for rapid detection of GaHV-1 in chickens. Fixed tissues allowing histopatological examination and detection of GaHV-1 by PCR, are a good option in areas where farms are located several hundred kilometers away from a diagnostic center, reducing problems with conservation of fresh samples and the risk of virus spread.
Documentos Relacionados
- Detection and molecular characterization of infectious laryngotracheitis virus in laying hens in Brazil
- Feline lymphoma in the nervous system: pathological, immunohistochemical, and etiological aspects in 16 cats
- Seroprevalence of Salmonella and Mycoplasma in commercial broilers, backyard chickens, and spent hens in the region of Triângulo Mineiro, State of Minas Gerais, Brazil
- Survey of infectious laryngotracheitis outbreak in layer hens and differential diagnosis with other respiratory pathogens
- Biochemical Parameters and Histopathological Findings in the Forced Molt Laying Hens