Similarly, isolates that change to one copy number for one

to two loci in the same farm and at the same time, especially loci that have high DI values, will have to be regarded as strains that originated from the same source, or as closely related strains. Thus, a cluster was classified into a group showing a 90% similarity via clustering analysis, with a difference of only one to three copy numbers (Table 3). Clustering analysis was performed with major isolates selected from YH25448 order 104 farms. They were classified into nine clusters and 23 genotypes. The major genotypes have been distributed nationwide and their geographic characteristics have not been found. In the local areas or districts, however, genetic horizontal transfers, which are epidemiological connections for farm to farm, were detected in a majority Eltanexor cell line of genotypes. Moreover, some clusters (for example, the H cluster) were indicated to be circulating in a specific local area, and were continuously confirmed to re-infect the neighboring farms by year (Figure 3). The MLVA profile analysis that was conducted on the basis of

the TRs copy numbers of 17 loci showed potentiality as an epidemiological tool in the restricted area. Its use as an epidemiological tool with the MLVA assay has already been reported [26, 41]. For 24 B. melitensis human isolates, the MLVA assay appeared to assist with the investigation of outbreaks. The isolates that clustered together in the same MLVA genotype indicated a common source of infection. According to the results of MLVA assay, a laboratory technician was proved to have an infection in the laboratory. Clinical, environmental, and animal isolates through the MLVA assay could allow the testing of the hypotheses regarding outbreak confirmation, extent of transmission, source, and reservoir. This assay encourages the use of a molecular method in epidemiological trace-back analysis. The maximum parsimony analysis of 48 foreign B. abortus strains and 23 Korean CHIR-99021 B. abortus

isolates was performed. The Korean isolates were not highly divided and were compact. When comparing with database (Brucella 2007) on the website http://​mlva.​u-psud.​fr[23, 30], the Korean isolates profiles were similar to the genotype 27 or 28 in panel 1, but they represented new genotypes. They were located near the Central and Southern American isolates (Figure 4). These results seem to prove that the B. abortus isolates have been localized by clonal expansion without the influx of other new strains, by the strict national quarantine. The stability of 17 loci was examined via both the in-vitro and in-vivo passages. In the in-vitro passage, B. abortus 544 showed only an increase or decrease in one TRs copy number at Bruce 04, 16 and Hoof 3 toward the end of passage course (Table 4). Whatmore et al.