Indirect Enzyme Linked Immunosorbent Assay for Diagnosis of Brucellosis in Buffaloes

R. Munir, S. T. ur Rehman, R. Kausar, S. M. Saqlain Naqvi, U. Farooq: Indirect Enzyme Linked Immunosorbent Assay for Diagnosis of Brucellosis in Buffaloes. Acta Vet. Brno 2008, 77: 401-406. Brucellosis is an important zoonotic disease causing significant economic losses worldwide. Early detection of this disease is essential for its control and eradication. Presently, an Indirect Enzyme Linked Immunosorbent Assay (I-ELISA) was developed using lipopolysaccharide (LPS) as antigen and compared with the commercial kit using one hundred negative and positive sera each from buffaloes. The agreement for the positive result between the developed and commercial I-ELISA was 78% and for the negative it was 100%. At 52.49%, 53.09%, 53.26%, 53.86% and 53.94% cut off the sensitivity was 100%, 100%, 97.53%, 88.93% and 86.42%, while the specificity was 84.03%, 84.87%, 85.71%, 87.39% and 87.39%, respectively, for developed I-ELISA. This developed test can be used for the screening of herds as the relative sensitivity is higher. Brucella abortus, I-ELISA, lipopolysaccharides (LPS) Brucellosis is a highly contagious, zoonotic and economically important bacterial disease of animals worldwide (OIE 2000). The disease is caused by various species of the genus Brucella, which are facultative, intracellular bacteria capable of surviving and multiplying inside the cells of mononuclear phagocytic system (Jarvis et al. 2002). The disease causes significant economic losses including abortion, loss in milk production, low fertility rates and cost of replacement of animals (McDermott and Arimi 2002). Timely diagnosis of the disease in sexually mature animals is very important and necessary for the control of this malady; also the transmission of the disease to humans is an important justification to undertake measures for its control and eradication. Early detection, control and elimination of reactors are important considerations for the control of brucellosis. Brucellosis is diagnosed by classical serological techniques i.e., agglutination, precipitation, complement fixation but these techniques have several drawbacks such as poor performance and lack of standardisation (OIE 2000). At present, application of the ELISA technique is considered a better test in early detection of infection than complement fixation test (Rojax and Alonso 1995). Indirect enzyme linked immunosorbent assays (I-ELISAs) have been developed and used in various countries for sero-diagnosis of brucellosis in cattle and other animals (Omer et al. 2001; Dajer et al. 1998; Molnar et al. 1998; Romero et al. 1995), however, such kind of work in buffaloes is limited (Guarino et al. 2001). The incidence of brucellosis in Pakistan is increasing particularly in large dairy herds. Earlier studies indicated low prevalence, i.e., 0.33 to 0.65% (Sheikh et al. 1967), whereas much higher prevalence is reported in recent studies, i.e., 21.05 to 26.1% (Sarwar 2000; Ramzan 1996; Akhtar et al. 1990). The incidence is higher in animals kept at organized farms rather than small holdings (Ahmad and Munir 1995; Lodhi et al. 1995; Ahmad et al. 1990, 1994). In spite of such a high incidence, none of the diagnostic tests has been Address for correspondence: Dr. Umer Farooq Animal Health Laboratories, Animal Sciences Institute, National Agricultural Research Centre, Park Road, Islamabad, Pakistan, 45500 Phone: 92-51-9255029 Fax: 92-51-9255420 E-mail: [email protected] http://www.vfu.cz/acta-vet/actavet.htm ACTA VET. BRNO 2008, 77: 401–406; doi:10.2754/avb200877030401