Determining of epidemiological characteristics of brucella strains isolated from clinical samples by multi-locus variable number tandem repeat analysis and pulsed field gel electrophoresis methods

Brucellosis is an infectious, usually subacute or chronic zoonotic disease caused by bacteria of the Brucella genus that can infect humans but primarily infects livestock. Considering the losses in animals that it causes, brucellosis is considered to be one of the most important diseases of domestic animals. In control and eradication of Brucella infections, early diagnosis and correct treatment of acute cases, timely vaccination of risk groups, detection of the source of the outbreak by genotyping the pandemic strains and monitoring of the bacterial movement in human and animal populations, thus, determination of the transmission path, discovery of the regional predominant genotypes, also investigation of vaccination and treatment options for the eradication of these genotypes, briefly, genotypic surveillance is very important. In recent years, is shown that the Multi-Locus Variable Number Tandem Repeat Analysis (MLVA) method can be successfully used for the the detection of the relationship between the genotypes of the Brucella species. In our study, we aimed to determine the epidemiological features of the clinical Brucella isolates using the MLVA and Pulsed-Field Gel Electrophoresis (PFGE) methods and to investigate the applicability of these methods in our Region. Following the identification to species level using the AMOS-ERY-PCR method of the phenotypically biotyped 118 Brucella isolates of animal origin, genotypic relationships were investigated using the PFGE and MLVA methods. By AMOS-ERY-PCR, 101 and 17 of the isolates were detected as B. melitensis and B. abortus, respectively, and these results were accordant with biotyping results. A total of the 28 genotypes was detected by MLVA and its discriminative power was very high (HGDI=0,9071). However, MLVA profiles of all of the 26 strains isolated as B. melitensis Rev-1 vaccine strain were identical and they were the predominant genotype. In conclusion, it was observed that the MLVA-16 method is discriminative for determination of the regional predominant genotypes. Besides, the results were shared with the Ministry of Agriculture, Food and Livestock and the relevant organizations.