Development of New Modified Simple Polymerase Chain Reaction and Real-time Polymerase Chain Reaction for the Identification of Iranian Brucella abortus Strains

Abstract

Brucellosis is primarily a worldwide zoonotic disease caused by <em>Brucella </em>species. The genus <em>Brucella</em> contains highly infectious species that are classified as biological threat agents. In this regard, the identification of <em>Brucella</em> can be a time-consuming and labor-intensive process posing a real risk of laboratory-acquired infection to the laboratory staff. This study aimed to present a novel conventional and real-time polymerase chain reaction (PCR) assay for the identification of <em>Brucella abortus</em> strains. Regarding this, two primers (bru ab2) were designed based on the unique loci encoding autotransporter-associated beta strand repeat-containing protein (ID:YP00113760). A total of 56 <em>Brucella</em> strains (e.g., reference, vaccinal, and field isolates) and <em>Yersinia enterocolitica</em>, as a non-<em>Brucella</em> isolate, were evaluated in conventional and real-time PCR systems. The results of the study indicated that 0.4 ng and 400 FG of genomic DNA of <em>B. abortus</em> strains can be detected by conventional and real-time PCR, respectively. The primers, bru ab2, were suitable for both PCR methods. Both methods were specific for the detection of all strains of the bacterium; however, real-time PCR assay was 1000-fold more sensitive than the conventional PCR method. Therefore, this new detection system could be a suitable selective modified method for the accurate identification of all <em>B. abortus</em> strains.