Molecular characterization of the Brucella ovis isolated in Nanjing

Abstract

Objective To analyze the molecular characteristics of Brucella strains isolated from Nanjing, understand strains genotying and clustering, and to provide a basis for prevention and treatment of brucellosis. Methods Multilocus sequence typing (MLST) and multiple locus variable-number tandem repeat analysis (MLVA) were used to analyze and characterize Brucella ovis strains isolated from 7 cases of sporadic cases in Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, from 2011- 2016, and cluster analysis was did with reference strain data from Jiangsu Province. Results The results showed that 7 strains were defined as sequence type (ST) 8 by MLST. They were typed into 7 subtypes and clustered in the Middle Mediterranean Cluster by MLVA. Strain NJ-2011-1 and two strains isolated from other cities in Jiangsu had the same MLVA genotype. Conclusions The results reveal ST8 is the predominant genotype in Nanjing. They have clustered in the Middle Mediterranean Cluster by MLVA. The 7 strains are sporadic. The transmission routes and risk factors are more complicated in the city. Various departments should strengthen the cooperation to control the source. Key words: Brucella; Multilocus sequence typing; Multiple locus variable-number tandem repeat analysis