Pathological and Immunohistochemical Examinations on Co-Infection with Coligranulomatosis and Marek's Disease in a Turkey Flock

Abstract

Coligranulomatosis, which induces hepatic granulomas, and Marek's disease, one of the important neoplastic diseases in poultry, rarely causes outbreaks in turkeys. In this study, etiological diagnoses were performed in the light of post-mortem, histopathological, microbiological, and immunohistochemistry studies of turkeys that died in a commercial establishment in the region of Konya. In the post-mortem examination, many grey-white foci with a diameter of 3-10 mm, which sometimes spread from serosa to the parenchyma, were found in the liver. Mucous exudate and hyperemia were detected in all segments of the intestine. For microscopic examination, all tissues were stained with Haematoxylin-Eosin and some selected liver tissues with Periodic Acid-Schiff, Ziehl-Neelsen, and Giemsa. Typical structures of pyogranulomas with an eosinophilic necrotic core in the liver were identified. Tumor foci formed by pleomorphic histiocyte and lymphoid cells were also observed in the liver, spleen, and intestines (jejunum and cecum). In the selected liver and intestinal sections, a positive reaction was obtained in tumor cells in immunohistochemical staining with the primary antibody specific for Marek's disease virus. In addition, Escherichia coli isolation was performed microbiologically in swaps and samples taken from lesioned areas of the liver. As a result of the examinations, other etiological agents that may cause hepatic granulomas in the turkeys were excluded, and coligranulomatosis and Marek's disease were diagnosed simultaneously in this turkey flock. It was concluded that in cases in which these two diseases are observed simultaneously, the diseases might interact with each other, and casualties may increase.

First report of Serotype-1 Marek’s disease virus (MDV-1) with oncogenic form in backyard turkeys in Turkey: a molecular analysis study

“…Gross and histopathological findings observed in the current study were mostly compatible with previously reported MD cases in avian species [ 1 , 30 ]. As an interesting finding, atherosclerosis that was detected in an artery of spleen in one turkey has also been noted in both natural and experimental MD infections of chickens [ 33 – 35 ], though its pathogenesis is yet to be clarified.…”

“…In the USA, the presence of MD in turkeys was first reported by Hauck et al [ 29 ] who detected MDV-1 in house-type and zoo-raised turkeys based on both immunohistochemical and molecular methods. In Turkey, first cases of MD in turkeys have been reported in 2020 based on pathological and immunohistochemical analyses [ 30 ]. The turkey is the natural host of HVT and the virus can circulate in turkey populations without causing disease [ 31 ].…”

Pathomorphological and molecular investigations in naturally infected Chukar partridges (Alectoris Chukar) with Histomonas meleagridis and Tetratrichomonas gallinarum

“…The character of necrosis observed especially in the liver in fatal typhlohepatitis cases is important to determine the etiology of the disease. As a matter of fact, when the lesions observed in the livers are evaluated, similar lesions in poultry are concentrated in M. tuberculosis (Gonzalez et al 2002), Escherichia coli (Ateş et al 2020), H. meleagridis (Clarke et al 2017), T. gallinarum (Liebhart et al 2014) and some fungal agents (Supartika et al 2006). Researchers reported that the macroscopic lesions observed in such cases contributed to the etiological diagnosis (Allen 1941, Supartika et al 2006.…”

“…In the present study, nodules with caseified foci were not observed in the bone marrow, spleen, and liver, and it was partially differentiated from tuberculosis in macroscopic examination. On the other hand, in a study in which only E. coli was detected, it was emphasized that lesions in the cecum were milder, as well as nodular structures that spread to the parenchyma in the liver and slightly protruded from the surface (Ateş et al 2020). Tetratrichomonas are characterized by cheesy remnants of bloody tissue in the caecum and granular, cream-colored, well-demarcated necrotic areas in the liver that are flush with or slightly protruding from the surface.…”

“…Mixed infections caused by H. meleagridis and T. gallinarum have been reported in blackhead disease, where the mortality rate reaches almost 100% (McDougald 2005). Apart from these two factors, there are other etiological agents that may cause similar clinical, macroscopic, and microscopic lesions (Supartika et al 2006, Ateş et al 2020. This situation leads to uncertainties in the diagnosis and can cause significant time and economic losses.…”