Differentiation and molecular typing of Brucella species isolated from aborted of livestock in the North and East of Iran

Brucellosis has always been among the most important economic and public health issues, somehow, each year it causes huge economic losses for the livestock industries. On the other hand, since brucellosis is a zoonotic disease, the importance of the issue in terms of public health is doubled. Therefore, it is necessary that by conducting epidemiological studies as a first step, identify the agent and then control and reduce the incidence of the disease. In this study, 170 samples were collected from aborted livestock in sheep, goats and cattle in the Golestan and Razavi Khorasan provinces, between 2015-2018. After the autopsy, different organs of the fetuses were cultured on the Columbia agar and MacConkey agar and then all of the samples were examined by using gram staining and standard biochemical tests. Overall, 60 Brucella spp. isolates were recovered and eventually, molecular typing and identification of Brucella spp. were conducted by using molecular techniques including Bruce-ladder Multiplex PCR and ERIC-PCR. Out of 60 Brucella spp. isolates, 59 strains were identified as Brucella melitensis and 1 strain as Brucella abortus, also all isolates despite their different geographic locations, had the same genetic patterns. The Bruce-ladder Multiplex PCR seemed to be a quick, safe and cost-effective method for molecular identification of Brucella isolates at the genus and species level. Although the ERIC-PCR technique in many studies is a powerful method for molecular differentiation of bacteria, it is better to use more precise and high-resolution techniques such as MLVA and MLST for confirmation the results of this study.