Global Veterinaria 12 (6): 865-868, 2014 ISSN 1992-6197 © IDOSI Publications, 2014 DOI: 10.5829/idosi.gv.2014.12.06.8477 Corresponding Author: Agus Setiyono, Pathology Division, Department of Clinic, Reproduction and Pathology, Faculty of Veterinary Medicine, Bogor Agricultural University, Jln. Agatis, Kampus IPB Darmaga, Bogor 16680, Indonesia. 865 Immunohistochemical Detection of Coxiella burnetii in Ruminants: A Case Study of Q Fever in Indonesia Agus Setiyono and Mawar Subangkit Pathology Division, Department of Clinic, Reproduction and Pathology, Faculty of Veterinary Medicine, Bogor Agricultural University, Jln. Agatis, Kampus IPB Darmaga, Bogor 16680, Indonesia Abstract: Q fever is a zoonotic disease caused by Coxiella burnetii, an obligate intracellular bacteria. Diagnosis of Q fever is usually determined by serological test and it should be time consuming. Detection of C. burnetii antigen immunohistochemically appears to be one of the best choice method for establishment of Q fever diagnosis in animals. The aim of this study was to detect the present of aetiological agent of Q fever using peroxide base method in Idul ‘Ied celebration cattles in Jakarta region, Indonesia. A total of 40 samples were collected during 2012 and examined. Gross lesion of the liver samples revealed multifocus necrotic hepatitis, granulomatous hepatitis, cirrhosis and fatty liver degeneration of parenchymal cells. The result showed positive immunoreactive to C. burnetii and occurs in 3 out of 40 liver samples.This is the first report on C. burnetii infection case diagnosed immunohistochemicallyin ruminants in Indonesia. Key words: Antibody Coxiella burnetii Diagnosis Immunohistochemistry Ruminants INTRODUCTION MATERIALS AND METHODS Query (Q) fever is a worldwide zoonosis [1] caused by Coxiella burnetii, an obligate intracellular and highly infectious bacterium that can lives in the monocyte or machrophage [2]. The most common syndromes observed in acute Q fever are prolonged fever of unexplained origin, emulsified immunogen incomplete freund’s adjuvant granulomatous hepatitis and atypical pneumonia [3, 4]. Liver involvement is common in acute Q fever and percutaneous liver biopsy can help in the diagnosis. On the other hand,cases of chronic Q fever hepatitis are rarely reported in the literature [5] and are frequently associated with endocarditis [6-8]. Diagnosis of Q fever can be established serologically by using fluorescent antibody technique [9-11] and or by polymerase chain reaction to detect genetic material deoxyribo nucleic acid of C.burnetii [12]. However, those techniques need more time and technically laborious.Immunohistochemistry (IHC) method had developed and thought to be a diagnostic tool for detecting antigen in the organ or tissue. The aim of this study is diagnose Q fever immunohistochemically in cattle which use for Idul ‘Ied celebration in Jakarta region, Indonesia. Production of anti-Coxiella burnetii Antibody: Production of antibody used immunogen formalin-fixed of C.burnetii-Nine Mile Strain according to the standard procedure [13] with minor modification. Briefly, the (CFA) were applied subcutaneously to New Zealand rabbit and followed with booster intramuscularly 3 weeks later using emulsified immunogen-incomplete freund’s adjuvant(IFA). Two to three weeks after boosting, the level of anti-C.burnetii antibody was checked and the sera considered to be harvested if the antibody titre significantly elevated. The generated antibody was then characterized and kept into some aliquots and store in- 20°C until use. Immunohistochemistry: 1 x 10 purified C.burnetii cells 6 were applied intraperitoneally to Hamster. After three weeks, Hamster was sacrificed and the spleen and liver were harvested. To evaluate the immunoreactivity of produced anti-C.burnetii antibodies toward certain C.burnetii antigen in the spleen or liver of Hamster,