Diagnosis of human brucellosis by PCR using l7/l12 and 16srRNA genes compared with common serological tests

Background: Brucellosis is one of the most common zoonotic diseases in the world which imposes a great financial burden on the endemic regions. Diagnosis of the human brucellosis is mainly based on blood culture and serological tests. PCR, however, is recommended for diagnosis at greater specificities and sensitivities. This study aims to compare the diagnosis of human brucellosis by PCR method using l7/l12 and 16srRNA genes and serological tests. Materials and Methods: In a cross-sectional study, a total of 700 blood samples were collected from patients suspected to brucellosis who had referred to the hospitals and laboratories of Ilam, Iran. The samples were selected through Rose Bengal test. Then 50 positive samples diagnosed by Rose Bengal test were assayed by Wright, Coombs Wright, and PCR using l7/l12 and 16srRNA genes and 50 negative samples diagnosed by PCR using these two genes were tested. Results: Of the total 700 samples assayed by Rose Bengal test, 125 were positive and the rest 575 were negative. The 50 positive Rose Bengal samples in PCR were shown to be positive by both genes and 50 negative Rose Bengal samples were shown negative by both samples. 47 samples in Wright test and 49 samples in Coombs test had titration levels above 1:60. Conclusion: PCR method has a higher sensitivity and specificity in diagnosis of human brucellosis in comparison with serological tests. Sensitivity of PCR by l7/l12 gene is similar to16srRNA and can be used for diagnosis of human brucellosis.