Abstract

Brucella is an intracellular pathogen capable of infecting animals and humans. The aim of this study was to identify Bruce//a spp in sera of high risk individuals by a polymerase chain reaction (PCR)-based method. A total of 180 patients suspected to have Brucellosis were examined by serological tests. To establish a PCR protocol for diagnosis of active brucellosis, DNA was extracted from the serum samples by using a commercial kit. PCR amplification was done for detection of Brace//a DNA using BCSP31 target gene and IS711 locus. The PCR assay showed that an amplicon of 223 bp was obtained in 73.8 (133/180) of the tested sera using primers (B4/B5) derived from a gene encoding the 31-kDa Bruce//a (thorn's antigen. In another PCR, an amplicon of 498 bp was obtained in 63.8 (115/180) of the samples using Bruce//a abortu.s.-specific primers derived from a locus adjacent to the 3'-end of IS711, and also an amplicon of 731 bp was produced in 4.4 (8/180) of the tested samples using Bruce//a melitensis-specific primers. When the Wright method was used as a gold standard, the sensitivity and specificity of the PCR technique for genus identification were found to be 96 and 80.7, respectively. However, the sensitivity value obtained with the species-specific PCR method was 82, and specificity was similar to that previous reported. This is the first report of a high frequency of Bruce//a abort us in patients suspicious of Brucellosis from the Zanjan province.