en تخصصي Special پژوهشي Original article <div style="border-bottom:solid windowtext 1.0pt; border-top:solid windowtext 1.0pt; border-left:none; border-right:none; padding:1.0pt 0in 1.0pt 0in"><span style="font-size:12pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:11.0pt">Background and Aims: </span></b><span style="font-size:11.0pt">Inclusion body hepatitis (IBH) is one of the most critical diseases in many countries with intensive poultry industries. In Iran, the etiological agent of IBH (fowl adenovirus) has been confirmed. This study aimed to determine the molecular detection and identification of fowl adenovirus involving IBH in chicken flocks during the year of 2020 in Iran.</span></span></span></span><br> <span style="font-size:12pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:11.0pt">Materials and Methods: </span></b><span style="font-size:11.0pt">For this purpose 150 liver tissue samples from 15 broilers flocks suspected in IBH infection were collected from Mazandaran province and were subjected to PCR analysis and histopathological examination. Polymerase chain reaction (PCR) and sequence analysis of the L1 hexon gene were utilized to detect and determine Fowl adenovirus (FAdV) genotypes in broiler farms. Histopathological sections were prepared and examined.</span></span></span></span><br> <span style="font-size:12pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:11.0pt">Results:</span></b><span style="font-size:11.0pt"> FAdV infection was confirmed by PCR in 14 out of 15 broiler flocks. Based on sequencing analysis of the hexon gene, they were genetically related to FAdV-11, a member of the fowl adenovirus D species. Homology among the isolates, Iranian isolates, and other counties was 94.44% - 97.11%. Histological examination revealed necrotizing hepatitis with basophilic and eosinophilic intranuclear inclusion bodies in the hepatocytes.</span></span></span></span><br> <span style="font-size:12pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:11.0pt">Conclusion: </span></b><span style="font-size:11.0pt">The results confirm previous reports about high prevalence of FAdV infection in broiler flocks and show continuos circulation of genotype 11 in Iranian broiler flocks</span><span style="font-size:11.0pt">.</span></span></span></span></div> Inclusion Body Hepatitis, Broiler, Iran, Hexon, Phylogenetic Analysis 22 27 http://journal.isv.org.ir/browse.php?a_code=A-10-266-2&slc_lang=en&sid=1 Fatemeh Moarefian moarefian.71@gmail.com 10031947532846006565 10031947532846006565 No Faculty of Veterinary Medicine, Science and Research Branch, Islamic Azad University, Tehran, Iran. Pejman Mortazavi sp.mortazavi@gmail.com 10031947532846006566 10031947532846006566 No Department of Pathology, Faculty of Veterinary Medicine, Science and Research Branch, Islamic Azad University, Tehran, Iran Hossien Hosseini hosseini.ho@gmail.com 10031947532846006567 10031947532846006567 No Department of Clinical Sciences, College of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran. Kaveh Parvandar Asadollahi kaveh_parvandar@yahoo.com 10031947532846006568 10031947532846006568 Yes Department of Clinical Sciences, Faculty of Veterinary Medicine, Science and Research Branch, Islamic Azad University, Tehran, Iran.