Pathological, immunohistochemical, and molecular findings in commercial laying hens and in backyard chickens naturally infected with the infectious laryngotracheitis virus

Abstract

KeywordsAvian infectious laryngotracheitis, conventional PCR, histopathology, immunohistochemistry, laying hen.Submitted: November/2013 Approved: June/2014 ABSTRACT 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.

Enfeksiyöz Laringotraheitis İle Doğal Enfekte Yumurta Tavuklarında Solunum Kanalı Lezyonları Üzerine İmmunohistokimyasal Çalışmalar

“…Preis et al [11] detected 70% positivity in the larynx and trachea tissues, and 53.8% positive results in the lungs in the field study immunohistochemically. They reported that these positive reactions were intracytoplasmic located in the mucosa and desquamated epithelial cells in the larynx and trachea, and parabronchial epithelium in the lung.…”

“…Immunohistochemical methods have recently been used to diagnose ILT by many researchers [8,9,11,[32][33][34] . IHC methods have been shown to be helpful for diagnosing ILT when macroscopical and histopathological findings are not possible [35] .…”

“…Preis et al [11] applied PCR method in fresh larynx, trachea, paranasal sinus, and lung from ILT suspected chickens, and they found positive reactions in 63.2% of larynx/ trachea, 56% in sinus and 57.6% in the lung. However, they found FFPE positivity was 25% in tracheal tissues.…”

“…Immunohistochemically, Preis et al [11] reported positive reactions in the cytoplasm of syncytial giant cells and epithelial layer in trachea, larynx, lung, and paranasal sinuses during field studies.…”

Immunohistochemical and clinical changes in the respiratory tract of chickens, naturally infected with the fowlpox virus

“…Microscopic examination of invaded tissues stained with hematoxylin and eosin reveals eosinophilic cytoplasmic inclusions, which are also detected with fluorescent antibodies and immunohistochemical methods (Ali et al, 2016;Bande et al, 2016). Viral particles with a typical virus morphology are determined by transmission electron microscopy with negative coloration, as well as in ultrathin sections of lesions (Preis et al, 2014).…”