• Korean Journal of Veterinary Service
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• v.32 no.2
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• pp.139-146
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• 2009

Bovine brucellosis is a zoonosis, long incubation period and chronic infectious disease, usually caused by Brucella abortus. This study was carried out to investigate the biotyping and biochemical characterization of B. abortus isolated from 208 farm 871 korean cattle and holstein diagnosed brucellosis by serological positive in Gyeongbuk province during the period from 2002 to 2006. B. abortus was isolated from 124 (14.2%) of 871 cattle, and isolated 110 (13.4%) of 820 Korean cattle and 14 (27.5%) of 51 holstein in breed. The uterus of korean cattle was isolated in 8 (17.8%) of 45 cattle and supramammary lymph none of holstein was isolated 11 (68.8%) of 16 cattle. 101 (12.5%) of 810 serological positive blood samples were isolated B. abortus. The isolation rate of B. abortus was correlated with antibody titers. The biochemical characterization of isolates was non-hemolytic, production of H$_2$S, oxidase-positive, catalase-positive, hydrolyzation of urea and growth of basic fuchsin dye medium. As a result, all of isolates was identified B. abortus bv 1. 124 isolates were susceptible to ampicillin, lincospectin, amikacin, gentamicin, kanamycin, neomycin, streptomycin, tetracycline, ciprofloxacin, norfloxacin and enrofloxacin.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.345-352
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• 1998

The diagnosis of brucellosis is currently based on serological and microbiological tests. However, the microbiological isolation and identification have several disadvantages such as time-consuming and laborious, and the serological methods have been reported to cross-react with antigens other than those from Brucella spp. To develop a sensitive and rapid diagnostic method for detection of Brucella species, the genus-specific primers were designed and synthesized from the sequence of gene encoding a 31kDa cell surface protein(BCSP) and a 36kDa outer membrane protein(OMPB) of B abortus. The amplified 711bp and 982bp DNA fragments were only visible in each species of Brucella by PCR method using the BCSP and OMPB primers, respectively. However, PCR product was not obtained with DNA from other Gram-negative bacteria. As little as 1pg of the B abortus genomic DNA could be detected by this PCR method. Using the PCR technique, semen samples from 185 bulls of Brucella-seronegative herds in Cheju island were examined for comparison of this PCR method with conventional methods in 1995. The semen samples from 5 bulls were positive by culture method and PCR, and one was positive and 5 were suspect by semen plasma agglutination test. However, the semen samples obtained from 177 bulls were negative by semen plasma agglutination, culture and PCR methods in 1996. The results of comparison tests suggested that PCR was a better test than agglutination test against semen of bulls. This study indicated that the PCR technique was a valuable for the diagnosis of bovine brucellosis, particulary in bull semens.

• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.131-135
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• 1993

Enzyme-linked Immuno sorbent Assay (ELISA) for the serological diagnosis of Brucella abortus was developed and compared with plate agglutination test. Cell wall antigen was extracted from Brucella abortus 1119-3 by sonication and with a sodium deoxychlate solution. Optimum protein concentration of coating antigen were $0.4{\mu}g/100{\mu}{\ell}$ protein on each microtiter plate well. Horse radish peroxidase (HRP) labeled protein-G was used as a tracer of reacted antibodies. ELISA confirmed the agreeable results of 40 cases out of 43 cases by plate aggulutination test. ELISA diagnosed positive cases(10 out of 12) and negative cases (1 out of 12) with dubious sera by plate agglutination test. From this results ELISA could be used for the early diagnostic tools of Brucellosis in cattle.

• Korean Journal of Veterinary Service
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• v.32 no.3
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• pp.257-264
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• 2009

Subtyping of Brucella abortus isolates is epidemiologically important for monitoring of bovine brucellosis outbreaks. Pulsed-field gel electrophoresis (PFGE) is considered as a gold standard of molecular typing methods to study the DNA polymorphisms of bacteria. In this study, we analyzed using PFGE the DNA fragment profiles of B. abortus isolated in Gyeongbuk province from 1998 to 2006. The genomic DNA was digested with the restriction endonuclease Xba I, Xho I and Smi I followed gel electrophoresis. No distinguishable patterns of the genomic DNA digested with Xba I and Xho I were observed among the field isolates of B. abortus tested in this study. But Smi I restriction enzyme resulted in two PFGE patterns consisting of 13-15 bands that ranged in size from 33 to 668bp by standard marker. The cluster analysis by DNA fingerprinting software showed 93.75% similarity between two PFGE patterns. No different PFGE patterns were recognized among the isolates originated from various years, regions and cow breeds.

• Korean Journal of Veterinary Research
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• v.48 no.4
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• pp.431-440
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• 2008

Brucellosis is one of the most important zoonosis in worldwide. As one of the control measures, attempts have been made to develop new diagnostic methods using filed isolates as a national policy in many countries. Currently, bovine brucellosis in Korea have been received attention in both public health and economical aspects due to sudden increase of outbreak. Based on the situation, we compared standard strain (B. abortus 1119-3) with field isolates to reveal the differences among them. Biological and biochemical charateristics, antibiotic resistance profiles, outer membrane proteins (OMPs) and lipopolysaccharide analysis of the strains were included in this study. For the diagnostic purpose, an attempt was made to find out a novel antigen from the Korean isolates by serological analysis. There were differences about 55 kDa, 36-38 kDa and 20 kDa in analysis of OMPs by SDS-PAGE and Western blot with positive sera ($\geq$ 1:400 in SAT titer). Also, a serological diagnostic method, ELISA was conducted using OMPs of the strains as novel antigen. Relationships between O.D. and SAT titer were analyzed using field sera showing different SAT titer. High correlation coefficient was observed between SAT titer and ELISA. Results from this study suggested that a new diagnsotic method should be developed using their own field isolates in each country.

• Korean Journal of Veterinary Research
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• v.45 no.1
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• pp.45-53
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• 2005

GroE that is a heat shock protein composed of GroEL and GroES is known as an immunodominant target of both the humoral and cellular immune responses in bovine brucellosis. This study was carried out to characterize groE gene encoding heat shock proteins of B. abortus isolated in Korea and to evaluate the immunogenicity of the GroE protein expressed in E. coli system. In PCR the specific signals with the size of 2,077 bp were detected in five strains isolated from the mammary lymphnodes of the dairy cattle that were serologically positive and the reference strains. In comparison of the sequences of nucleotides and amino acids among the strains, GroES showed 100% identity in both sequences. GroEL was evaluated 99.0~99.9% in nucleotides and 98.0~100% homology in amino acids. The groE gene including groES and groEL was inserted into pET29a vector and constructed pET29a-GroE recombinant plasmids. The inserted groE was confirmed by digestion with Nco1 and EcoR1 endonucleases and nucleotide sequencing. E. coli BL (DE3) was transformed with pET29a-GroE, named as E. coli BL (DE3)/pET29a-GroE. In SDS-PAGE, it was evident that the recombinant plasmid effectively expressed the polypeptides for GroES (10 kDa) and GroEL (60 kDa) in 0.5, 1 and 2 hours after IPTG induction. The immuno-reactivity of the expressed proteins were proved in mouse inoculation and Western blot analysis.