Molecular diagnosis of brucellosis-causing bacteria isolated from patients with brucellosis with the help of trpE and omp25 genes by PCR

Background and Objective: Brucellosis is a zoonotic disease in humans and animals. Nowadays, several serological tests for brucellosis diagnosis are available but all of these tests have their own limits. The aim of the present study was to use PCR according to omp25 and trpE genes for the molecular analysis of the individuals with brucellosis.

Materials and Methods: In this study, 30 clinical isolates were studied. All the patients were diagnosed with positive immunological tests such as Wright and Coombs. Samples of blood were cultured (BACTEC) and incubated at 37 degrees Celsius for 5 days and then they were cultured for 3 days on Brucella agar. DNA was extracted from the colonies by Kit. The extracted DNA was used as template for accurate diagnosis of bacterial strains with gene-specific primers in PCR reactions omp25 and trpE.

Results: In this study, all the samples selected were seropositive from which the colonies were obtained. DNA extracted from the colonies by the use of kit was proved by spectrophotometer device. Also, the results of the amplification reaction and the amplified bands of 486 and 490 bp for omp25 and trpE genes indicate the validity of the primers. By reproduction of these components, the genus Brucella was specifically identified.

Conclusion: Using the PCR technique, on the contrary to the serological diagnostic methods, facilitates the tracing and identifying the bacteria, especially those with slow growth rate. In this research, the trpE gene which has been not used in the diagnosis of brucellosis in Iran was exploited. The results of this study indicate that by amplification of some specific regions of the omp25 and trpE genes which are belonged to the conserved parts of the genus Brucella, identifying the bacteria Brucella under PCR method is possible.