• 대한수의학회지
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• 제28권2호
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• pp.339-343
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• 1988

Serological study and isolation of Brucellae from dairy cattle were carried out in Kyungpook area of Korea during the period from 1984 to 1985. Biotyping of the isolates was done. Of the 11168 cattle in 2479 herds examined, 27 cattle (0.24%) in the 17 herds (0.69%) were serologically positive for brucellosis. Brucella abortus was recovered from 20 (74.1%) of the 27 infected cattle, and all the strains of the isolates belonged to biotype 1. Of the tissues cultured for brucellae, the supramammary lymph nodes had the highest rate (55.6%) of recovery of brucella organisms.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.158-163
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• 2019

Brucellosis is one of the most important zoonotic diseases that lead to a great amount of economic losses. Prevention and diagnosis are both necessary to eradicate this disease. The identification and evaluation of different antigens of Brucella spp. play a key role in the progress of diagnostic programs. In this study, we designed, produced, and evaluated a 24-kDa polypeptide containing antigenic epitopes of VirB2, 3, and 9 of Brucella abortus for use with the ELISA kit. The produced polypeptide is appropriate for diagnosing brucellosis in bovines by a laboratory diagnostic kit, with 100% sensitivity and 97.5% specificity.

• 대한수의사회지
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• 제34권9호
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• pp.640-644
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• 1998

• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1837-1843
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• 2017

Knowledge of avian host responses to brucellosis is critical to understanding how birds resist this infection; however, this mechanism is not well established. On the other hand, temperature has a major involvement in the physiology of living organisms, and cell death induced by heat is attributed to protein denaturation. This study demonstrates the direct bactericidal effect of a high temperature ($41^{\circ}C$) on Brucella abortus that resulted in the gradual reduction of intracellular bacteria and inhibited bacterial growth within avian macrophage HD11 in an increasing period of time. On the other hand, this study also revealed that high temperature does not affect the rate of bacterial uptake, as confirmed by the bacterial adherence assay. No significant difference was observed in the expression of target genes between infected and uninfected cells for both temperatures. This study suggests the susceptibility of B. abortus to bacterial death under a high temperature with an increased period of incubation, leading to suppression of bacterial growth.

• Journal of Microbiology and Biotechnology
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• 제22권4호
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• pp.567-570
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• 2012

In vitro activities of 13 antibiotics were assessed against 85 Brucella abortus isolates from naturally infected cattle in the Republic of Korea during 1998-2006, using broth microdilution test. Tetracyclines showed the most excellent activity against B. abortus, displaying MIC values of 0.5 ${\mu}g/ml$ or below. In particular, minocycline showed the lowest $MIC_{50/90}$ values (0.125/0.125 ${\mu}g/ml$) in this study. Among four fluoroquinolones tested, ciprofloxacin ($MIC_{50/90}$, 0.5/1 ${\mu}g/ml$) and norfloxacin ($MIC_{50/90}$, 8/8 ${\mu}g/ml$) had the most and the least activities, respectively. Gentamicin ($MIC_{50/90}$, 1/1 ${\mu}g/ml$) was more effective than streptomycin, erythromycin, rifampin, and chloramphenicol ($MIC_{50/90}$, 2/2 ${\mu}g/ml$).

• Journal of Microbiology and Biotechnology
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• 제30권5호
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• pp.642-648
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• 2020

In this study, we investigated the effects of linoleic acid (LA) treatment on Brucella abortus infection in professional phagocyte RAW264.7 cells, particularly during the pathogen's invasion and intracellular growth in these cells, as well as in murine model BALB/c mice focusing on bacterial splenic proliferation and immunoregulatory activities. LA inhibited the growth of Brucella in a dose- and time-dependent manner. The ability of the pathogen to enter the phagocytes was inhibited as was its survival within these cells. This was accompanied by increased nitrite accumulation in these cells at 24 h post-infection. The concentration of LA used in the present study did not affect the total body weight or liver function of the mice. During Brucella infection, the total splenic weight of these animals was not changed; rather, resistance to bacterial proliferation was enhanced in the spleen. Furthermore, mice treated with LA displayed elevated levels of IL-12 and IFN-γ but reduced levels of IL-10 during infection. The findings in this study showed the regulatory role of LA against B. abortus infection suggesting its potential use in designing intervention strategy for brucellosis.

• 대한수의학회지
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• 제56권3호
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• pp.147-153
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• 2016

A total of 782 blood and 465 tissue samples from 1,039 wild animals and 127 dairy goats were collected from January 2011 to December 2013 in 10 provinces of South Korea and tested for the presence of brucellosis. The Rose Bengal test revealed that 8.0% (52/650) of the serum samples were seropositive, while 4.2% (33/782) of the serum samples were positive for Brucella antibodies by competitive enzyme-linked immunosorbent assay. Of the 650 sera examined, only 16 (2.5%) were positive by both serological tests. Direct polymerase chain reaction (PCR) assay using B4/B5 primers for Brucella abortus (BCSP31) revealed the prevalence of Brucella to be 26.5% (129/487) in blood samples and 21% (98/465) in tissue samples while, 16S rRNA PCR detected Brucella DNA in 6.8% (33/487) and 2.6% (12/465) in blood and tissue samples, respectively. Of PCR-positive samples, only 6.2% (30/487) of blood samples and 2.4% (11/465) of tissue samples were found to be positive by both BCSP31 and 16S rRNA PCRs. However, Brucella strains were isolated by blood culture from only two out of 487 blood samples (0.4%). This characterization and identification of pathogenic Brucella isolates is the first to clearly indicate that the organisms were Brucella abortus biovar 1.

• Molecules and Cells
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• 제44권7호
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• pp.517-528
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• 2021

A recent genetic study with Brucella abortus revealed the secretion activator gene A (SagA) as an autolysin component creating pores in the peptidoglycan (PGN) layer for the type IV secretion system (T4SS) and peptidoglycan hydrolase inhibitor A (PhiA) as an inhibitor of SagA. In this study, we determined the crystal structures of both SagA and PhiA. Notably, the SagA structure contained a PGN fragment in a space between the N- and C-terminal domains, showing the substrate-dependent hinge motion of the domains. The purified SagA fully hydrolyzed the meso-diaminopimelic acid (DAP)-type PGN, showing a higher activity than hen egg-white lysozyme. The PhiA protein exhibiting tetrameric assembly failed to inhibit SagA activity in our experiments. Our findings provide implications for the molecular basis of the SagA-PhiA system of B. abortus. The development of inhibitors of SagA would further contribute to controlling brucellosis by attenuating the function of T4SS, the major virulence factor of Brucella.

• 한국동물위생학회지
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• 제19권3호
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• pp.189-198
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• 1996

The survey was performed to provied details about the pattern of bovine brucellosis occurred in Kyunggi province area. The results obtained through the investigations were summarized as follows. Five hundred seventy - three cattle of bovine brucella reactor were occurred in 14 districts among 31 districts in Kyunggi province in 1989-1995. Among them, 370 cattle(64.5% ) were bred in Eastern area(Ichon, Yeju, Kwangju) and 153 cattle(26.7% ) in Southern area(Yongin, Ansung, Peungtack) And the number of farms occurred by bovine brucellosis was 110 ones. When we investigated the occurrance frequency for the 110 farms, the ratio of farms which was brocken out just one time was 67.3a and more than twice was 32.7%. In 573 cattle, 271 cattle were reoccurred in farms which had broken out the bovine brucellosis more than one time. And this survey said the interval of reoccurrance was like this ; within a month 50.2%, within two month 19.2%, within four month 7.4%, within six month 7.4%, within an year 15.1%, within 2 year 7.0%. Brucella abortus was isolated from 38 cattle of the 61 ones cattles, and in type all isolated belong to biotype 1.

• 대한수의학회지
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• 제33권1호
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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.