Sequencing of an atypical Brucella strain 16S rDNA

Abstract

Objective To sequence an atypical Brucella strain 16S rDNA, and to evaluate the feasibility of 16S rDNA sequencing method for identification of Brucella. Methods Preliminary identification of atypical strains was carried out with conventional method. Strain DNA was extracted, and 16S rDNA complete sequence was bidirectional sequenced, and Blast in NCBI and DNAMAN software were used for comparison of the sequence identities of the 16S rDNA. Moreover, 16S rDNA complete sequence of the stains those were known to cross- react serologically with Brucella was downloaded from GenBank, MEGA 6.0 was used to construct the phylogenetic tree. Results The conventional identification results revealed that it was an atypical Brucella, the gene similarity between the sequences of the test strain 16S rDNA and Brucella was 99%, between 16S rDNA sequence of Brucella abortus 544A and Brucella melitensis 16M was 96.99%. Phylogenetic tree revealed that the test stain was a Brucella, and closely related to Brucella abortus 544A and Brucella melitensis 16M. Conclusion The test strain is an atypical Brucella, and 16S rDNA sequencing analysis is a simple, rapid, and accurate identification method for atypical Brucella. Key words: Brucella; 16S rDNA; Sequence analysis