Phylogenetic analysis of Brucella field isolates according to rpo B gene modifications

Introduction 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 Amos PCR and Multiplex PCR and Bruce ladder techniques according to rpo B gene for the molecular analysis of the individuals with brucellosis. Materials and Methods: 50 clinical isolates were studied.11 patients were diagnosed with positive immunological tests such as Wright,Coombs Wright,Rosbangal.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.The nucleotide sequence of rpo B gene in the studied strains was obtained from the NCBI,BLAST.Draw phylogenetic tree of rpo B gene for the species examined using MEGA6 software Was performed.Analysis of the structure of rpo B gene was carried out in terms of nucleotide differences and phylogenetic tree mapping by neighborjoining method. Results: In this study,all the samples selected were seropositive from which the colonies were obtained.The results of the amplification reaction and the amplified bands of 1432 bp for rpo B gene indicate the validity of the primers.According to this study,protected areas form a small part of the gene sequence,which indicates the high polymorphism of this gene as well as its susceptibility to nucleotide changes and mutations,especially in area 81 bp. Conclusion: We showed that PCR and SNPs retrieved from the B. melitensis draft full genomes were sufficient to resolve the interspecies relationships between B. melitensis strains and to discriminate between the vaccine and endemic strains.

کلیدواژه ها:

Brucella ، Phylogenetic analysis ، Molecular typing ، Brucella field isolates ، rpo B