The Efficacy of Multiplex PCR in Comparison with Agglutination and ELISA in Diagnosis of Human Brucellosis

Background: Human brucellosis is an endemic disease in many countries including Iran. Exact diagnosis of brucellosis is not just based on clinical symptoms, because it will be considered in differential diagnosis of other diseases. Therefore, defining organism in culture or identification of organism by serological and molecular methods for confirming clinical diagnosis is necessary. Our aim was to develop a diagnostic PCR assay and define the optimal clinical specimen for this test.

Materials and Methods: This cross-sectional and descriptive study was from February 2011 to November 2012. Results of standard agglutination test (SAT) and specific immunoglobulin IgG and IgM by enzyme-linked immunosorbent assay (ELISA) were compared with multiplex PCR in 116 patients with suspected brucellosis referred to the Ali Ebn-e-Abitaleb hospital, Rafsanjan, Iran. Their sera were collected and tested by SAT, ELISA and multiplex PCR. DNA was extracted from serum samples and examined by multiplex PCR involving specific primers for Brucella melitensis and Brucella abortus based on IS711 in the brucella chromosome.

Results: Brucellosis was confirmed in 116 patients (75% male and 25% female) based on applied diagnostic methods and clinical features. Results of ELISA, the SAT, and PCR were positive in 116, respectively. B. abortus and B. melitensis were detected in 101 and 15 patients.

Conclusion: The results of present study showed that multiplex PCR assay is a rapid and sensitive technique for diagnosis of brucellosis compared to SAT. However it is more accurate when coupled with conventional methods.