[The value of polymerase chain reaction methods targeting two different gene regions for the diagnosis of brucellosis].

The conventional laboratory diagnosis of brucellosis, a worldwide zoonotic infection, depends on the isolation of organisms in cultures and serological methods. Recently, polymerase chain reaction (PCR) which is a widely used method for the identification of especially fastidious or slowly growing organisms, has been introduced for use in the diagnosis of brucellosis. The aim of this study was to evaluate the molecular diagnostic value of PCR method targeting two different gene regions in Brucella. For this purpose, the blood samples of 29 acute brucellosis patients (of them 13 were blood culture positive) whose serum agglutination titers were > or = 1/160, and 10 cases whose serum agglutination titers were 1/80 with negative blood culture, have been searched by PCR, targeting two different gene regions of Brucella DNA, and the sensitivities of the methods were compared. As a result, 51.7% of the patients were found to be positive by amplification of IS6501 gene (an insertion sequence of Brucella spp) and 48.3% of the patients were positive by amplification of 223-basepair region of the gene encoding 31-kDa Brucella abortus protein, by semi-nested PCR. In conclusion, the diagnostic application of PCR in brucellosis may be a good alternative compared to conventional methods by providing results in a short period of time, however its disadvantages such as low detection limit of bacterial DNA in blood samples, increased risk of carry-over contamination and higher cost must be further evaluated.