Isolation and molecular identification of Brucella species fromhuman and livestock in Hamadan province by PCR method

Background and Aim : Brucellosis is a widespread zoonotic disease causing considerableeconomic and public health problems. Despite animal vaccination, brucellosis remains endemic insome areas such as Iran, especially in the Hamadan province. The aim of this study was theisolation and molecular identification of Brucella abortus and Brucella melitenensis species fromhuman and animal samples in Hamadan province.Methods : In this study, ۷۰ isolates were examined, so that ۳۰ isolates were studied from patientswith a clinical diagnosis of brucellosis who referred to the Infectious Diseases Ward of SinaHospital in Hamadan Province between Nov ۲۰۲۱ and July ۲۰۲۲. Blood samples were collectedfor the diagnosis of brucellosis using the BACTEC blood culture system . And ۴۰ isolates wereisolated from the livestock of Hamadan province (including cows, sheep and goats). In this way,culture and isolation were done from milk samples, abortion products, amniotic fluid and lymphnodes from animals with positive serological tests . The initially identified Brucella isolates werefurther characterized using phenotypic and molecular approaches. . In molecular studies, theisolates were identified with specific primers for the identification of Brucella genus ( B۴,B۵) ,and in the next step, specific primers for the identification of B. abortus and B. melitensis species(IS۷۱۱ AB , IS۷۱۱ BM) were used.Results : A fragment of ۲۲۳ bp, which is specific to the genus Brucella, was observed in allisolates, and a fragment of ۴۹۸ bp related to Brucella abortus (beavers ۱, ۲, and ۴) was detected in۲۵% of the isolates, ۱۵% of which were related to animal isolates and ۱۰% was related to humanisolates. And finally, a fragment of ۷۳۱ bp for Brucella melitensis was identified in ۷۵% of theisolates.Conclusion : The identified primers revealed high levels of sensitivity and specificity. Therefore,they can be considered along with culture in clinical trials.