Polymerase chain reaction (PCR) diagnosis of human brucellosis (l7/l12 and 16srRNA genes) compared with immunocapture-agglutination test (brucellacapt) and common serological tests

Abstract

Diagnosis of the human brucellosis mainly depends on blood culture and serological tests. The most commonly used tests are the serum agglutination test (SAT), Coombs anti-Brucella, and Rose Bengal tests. New diagnostic tests such as immunocapture-agglutination test (Brucellacapt) and polymerase chain reaction (PCR) have been used. This study aims to compare PCR method by using L7/L12 and 16srRNA genes with Brucellacapt and serological tests in diagnosis of Brucellosis. A total of 754 different suspected brucellosis were tested during the period from March, 2008 to February, 2009. They were assayed by Rose Bengal test, Brucellacapt, Coombs tests, SAT and PCR. Our results had shown that out of 754 sera, 125 were positive by Rose Bengal test. Thus, frequency of brucellosis by Rose Bengal test was 16.5%. In PCR, all of samples were differentiated. Forty nine (6.5%) samples in Coombs test and 47 (6.2%) samples in SAT were positive. The results in 1:40 and 1:80 were equal for Brucellacapt and Coombs tests and different for SAT. The results from the present study show a higher sensitivity and specificity of PCR for the diagnosis of human brucellosis than serological tests. Sensitivity of the PCR by l7/l12 gene and 16srRNA were similar and could be used for diagnosis of human brucellosis. Sensitivity of Brucellacapt test was higher than Coombs tests and SAT, although the sensitivity of PCR assay was higher than all of them.