Pathologic changes and virus detection in organs of chicken infected with fowl adenovirus serotype 8b

Hamsa, Nurien Najiehah (2023) Pathologic changes and virus detection in organs of chicken infected with fowl adenovirus serotype 8b. [Project Paper] (Submitted)

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Abstract

Inclusion body hepatitis (IBH) is a common disease caused by fowl adenovirus (FAdV) including FAdV serotype 8b. This disease causes significant economic losses to the poultry farm due to a decrease in production. Previously, FAdV serotype 4 induce immunosuppressive effect in chickens with high mortality. The aim of this study is to determine the pathological changes and to detect presence of the virus in organs of chickens infected with FAdV serotype 8b. Thirty-six (36) specific pathogen free (SPF) day-old chicks were divided into 2 groups: FAdV infected group and the control group. FAdV infected group was inoculated with 1ml FAdV isolate, UPM1901, at virus titer 107.1TCID50/ml via oral route at day old while, control group remained uninoculated throughout the trial. Any mortality or clinical signs were recorded throughout the study. Body weight, liver and bursa of Fabricius weight were recorded at day 0, 12 hours (h), 24h, 3 and 7 post-inoculation (pi). Sampling was conducted in chickens for collection of blood for serum biochemistry test. Organs such as liver, kidney and lymphoid organs (thymus, cecal tonsils, Bursa of Fabricius and bone marrow) were harvested for histopathological analysis and polymerase chain reaction (PCR) detection. It shown that chickens infected with FAdV showed clinical signs of dullness, ruffled feathers, depression and sudden death. Mortality was observed as early as day 3pi and peaked at day 4pi. Body weight of chickens in FAdV infected group (46.8 ±1.39) was significantly lower than control group (56 ± 1.87) (p<0.05) at 3pi due to reduced feed consumption as a result of FAdV infection. Gross lesion findings revealed swollen, haemorrhages, necrosis and yellowish discoloration of liver in the infected group at day 3 and 7pi. Liver weight for FAdV infected group was increased at day 3pi (3.75 ± 0.23) and 7pi (4.7 ± 0.1) compared to the control group. Microscopically, numerous basophilic intranuclear inclusion body (INIB) was observed in the hepatocyte at day 3pi onwards. Based on the PCR findings, FAdV was initially detected in bone marrow at 12hr pi followed by the other organs at 24h pi in spleen, liver and cecal tonsils. At day 3 and 7pi, viral DNA was detected in all the selected organs. This study proves that FAdV serotype 8b induced pathological changes in liver and lymphoid organs with presence of virus DNA as early as 12h pi. Thus, FAdV isolate, UPM1901, is highly potential to be used as challenged virus for future efficacy study.

Item Type:	Project Paper
Faculty:	Faculty of Veterinary Medicine
Depositing User:	Ms Nurhaznita Mahmood
Date Deposited:	12 Aug 2024 03:08
Last Modified:	12 Aug 2024 03:08
URI:	http://psaspb.upm.edu.my/id/eprint/2036

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