• 대한수의학회지
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• 제32권2호
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• pp.181-194
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• 1992

Two hundred and eighty nine strains of Yersinia enterocolitica isolated from healthy pigs were tested for the presence of 40~50 Megadalton virulence-associated plasmids and plasmidmediated in vitro virulence-associated properties, i.e., congo red uptake, calcium dependency, autoagglutination, CRMOX reaction, crystal violet binding and pyrazinamidase reaction. The correlationships between in vitro virulence-associated properties and the presence of 220 Kdalton outer membrane protein(OMP) were examined in strains with or without virulence-associated plasmids. The correlationships between the presence of plasmids on the production of the OMP and the expression of in vitro virulence-associated properties were studied with $CRMOX^+$ strains and acridine orangecured $CRMOX^-$ mutants. The results were as follows : 1. Of the in vitro virulence-associated tests with 289 strains of Y enterocolitica, 275 strains (95.2%) were positive for pyrazinamidase test, and followed by in order of crystal violet binding test, 226 (79.2% ) ; CRMOX test, 190 (65.7%) ; autoagglutination test, 1.85(64.0%) : calcium dependency test, 86 (29.8%) and congo red uptake test, 47(16.3%). 2. The correlationship between autoagglutination and CRMOX test(r=0.90) was highly significant (p<0.01). 3. In 190 strains(65.7%) bearing the virulence-associated plasmids(MW 40~50 Mdalton), the correlation between the presence of plasmids and their in vitro virulence-associated properties were highest with CRMOX test(r=0.93) and followed by in orders of AAG test(0.81), CV test(0.46), PYZ test(0.37) and CD test(0.18), but no correlationship between the presence of plasmids and CR test(-0.11). 4. The $CRMOX^+$ strains produced the 220 Kdalton OMP when they were cultured at $37^{\circ}C$, but not at $26^{\circ}C$. The presence of 220 Kdalton OMP was correlated significantly with in vitro virulence properties and the presence of virulence-associated plasmid, respectively. 5. In the isogenic $CRMOX^-$ mutant strains, of which plasmid were cured by treatment with acridine orange not only in vitro virulence-associated properties(CR 100%, CD 100%, AAG 82.6%, CV 58.3%) disappeared but also 220 Kdalton OMP(100%) was not produced. These results indicate that the positive CRMOX reaction is plasmid-mediated and the CRMOX test is potential as an in vitro virulence tests with Y enterocolitica.

• 미생물학회지
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• 제26권3호
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• pp.262-269
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• 1988

한국에서 분리한 Yersinia enterocolitica의 병원성 여부를 조사하기 위하여 지가응집 시험, 칼슘 의존성 시험, HeLa 세포 침투시험, Sereny 시험, Crystal violet 결합시험과 plasmid의 전기영동을 실시하여 다음과 같은 결과를 얻었다. 병원성 Y. enterocolitica는 자가응집, 칼슘 의존성, crystal violet 결합시험에서 양성반을을, 비병원성 균주는 음성반응을 각각 나타내었다. 그러나 양성반응은 $37^{\circ}C$에서만 나타나 병원성의 발현이 온도에 의존됨을 알 수 있었다. Sereny 시험에서 혈청형 0:8인 표준균주만이 양성반응을 보인 반면에 혈청형 0:3, 0:9인 실험균주들은 대부분 음성반응을 나타내어 Y. enterocolitica의 병원성은 혈청형에 따라 실험동물에서 다르게 발현됨을 알 수가 있었다. HeLa 세포 침투시험에서 실험균주 모두가 양성반응을 보여 병원성 균주를 구분하기에는 부적합하였다. 대부분의 병원성 균주는 36-38Mdal의 plasmid를 가지고 있었으나 비병원성 균주는 없었으며, plasmid가 자가응집 및 칼슘 의존성, crystal violet 결합에 관여함을 알 수가 있었다.

• 대한수의학회지
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• 제32권3호
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• pp.369-376
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• 1992

This paper dealt with plasmid DNA profile in 98 Salmonella(S) isolated from pigs and cattle sources in Taegu, Gyeongbook and Gyeongnam during the period from 1984 to 1987. Also we were studied for restriction enzyme analysis of the plasmid DNA, and mouse infection, Sereny test and normal setum resistance test in guinea pig for S typhimurium and S enteritidis harbored or cured 60 megadalton(Md) plasmid and 36 Md plasmid, respectively. Of the 13 Salmonella isolated from cattle, 7 Salmonella harbored one or more plasmids and molecular sizes of the large plasmids were 60 Md for S typhimurium and 36 Md for S enteritidis. Of the 85 Salmonella isolated from pigs, 47 Salmonella were confirmed as being one or more plasmids, and all the S typimurium stains harbored 60 Md plasmid. In enzyme digestion with 8 types of restriction endonuclease for 60 Md plasmid DNA of S typhimurium, cleavage patterns were varied to enzymes, and the DNA was segmented into 4 to 15 fragments. In restriction enzyme analysis of 36 Md plasmid DNA obtained from four strains of S. enteritidis, the DNA showed the same cleavage patterns obtained with Eco RI, Hind III and Bam H I, and was segmented into 3 to 5 fragments. In virulence for mice by measuring the 50% lethal dose ($LD_{50}$), the $LD_{50}$ values obtained for 60 Md virulence-associated plasmid harbored strains of S typhimurium and 36 Md virulence-associated plasmid of S enteritidis were up to $10^4$-fold lower than the values obtained for the plasmid-cured strains of the same serotype. Only the plasmid harbored strains were resistant to the bactericidal activity of 90% guinea pig serum, and only they gave positive responses in sereny test. We suggested that their plasmid DNA might be associated with virulence for mice.

• 대한수의학회지
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• 제51권1호
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• pp.15-20
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• 2011

In this study, we isolated 12 of Brucella (B.) spp. from cattle, which have been positive in Rose Bangal test and tube agglutination test in Gyeongbuk province in 2009. According to AMOS PCR analysis, isolated 12 strains were identified as B. abortus. Murine derived macrophage, RAW 264.7 cells, were infected with isolated 12 strains or reference strain (B. abortus 544), and bacterial internalization were characterized. According to these results, we divided the isolated strains into the following three groups: class I, lower internalization than that of B. abortus 544; class II, similar internalization to that of that of B. abortus 544; class III, higher internalization than that of B. abortus 544 within RAW 264.7 cells. Furthermore, intracellular growth, bacterial adherent assay, LAMP-1 colocalization, virulence in mice and surface protein pattern were characterized. From these results, representative strains of class III showed lower LAMP-1 colocalization, higher adherent efficiency, higher virulence in mice than those of B. abortus 544, and showed different pattern of surface proteins. These results suggest that B. abortus field strains, isolated from cattle in Korea, possess various virulence properties and higher internalization ability of field strain may have an important role for its virulence expression.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.515-519
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• 2004

Listeria spp. were isolated from a total of 402 naturally contaminated domestic ready-to-eat (RTE) vegetable samples by the conventional Food and Drug Administration protocol and confinned by API-Listeria kit. Also, the susceptibility to 12 antibiotics, polymerase chain reaction (PCR) assay for virulence gene of pathogenic Listeria monocytogenes isolates, and in vitro virulence assay using myeloma and hybridoma cells from murine and human sources were tested. Among the samples, 17 samples (4.2％) were found to be contaminated with Listeria species. Among the 17 strains of Listeria spp. isolates, only 2 strains (11.8％) of L. monocytogenes and 15 strains (88.2％) of L. innocua were identified. Antibiotic susceptibility test showed that the Listeria spp. isolates were very susceptible to the antibiotics tested, except for nalidixic acid. Among 17 strains of Listeria spp., PCR analysis showed that 2 strains of L. monocytogenes isolates proved to have a virulence hly gene, but none of L. innocua had the hly gene. Also, hybridoma Ped-2E9 cells assay showed that only L. monocytogenes isolates killed approximately 95-99％ hybridoma cells after 6 h, but L. innocua isolates had about 0-5％ lethal effect. These results indicate that PCR assay with hly primer or hybridoma Ped-2E9 cells assay could be used as a good monitoring tool or in vitro virulence test for L. monocytogenes.

• 환경위생공학
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• 제15권4호
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• pp.105-113
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• 2000

We have isolated 65 strains(2.0%) of Y. enterocolitica among 3,219 water samples from 380 spring water sites in Seoul from 1994 to 1999. The biochemical characteristics of isolated strains revealed that TSI was A/A, urea, M.R.($37^{\circ}C$), nitrate, motility($37^{\circ}C$), sorbitol, maltose, manitol, arabinose, mannose, trehalose, xylose were positive(100%) and H$_2$S, arginine, lysine, oxidase, citrate, V.P.($37^{\circ}C$), DNase, motility($37^{\circ}C$), dulcitol, adonitol, lactose and raffinose were negative(100%). In in vitro virulence test, positive rate of AAG and CRMOX were 9.2% and 4.6%, respectively. However in the virulence gene detectable gene detectable test by multiplex-PCR using ail, yst, virF genes, 65 strains were all negative, meaning that Y.enterocolitica strains from domestic spring water were not detected for the virulence. Otherwise, mutiplex-PCR which using ail, yst and subgenus-specific primer pair was the best for identifying the virulence of Y. enterocolitica.

• 대한수의학회지
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• 제29권2호
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• pp.69-73
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• 1989

Nine strains of Yersinia species isolated from pigs and dogs in Korea, comprising 5 strains of Yersinia enterocolitica, 2 strains of Y kristensenii and each strain of Y pseudotuberculosis and Y intermedia, were examined for the presence of virulence-associated plasmids, calcium dependency and provocation of guinea pig conjuntivitis($Ser{\acute{e}}ny$ test). Three strains of Y enterocolitica isolated from pigs were positive in calcium dependency and harbored one plasmid of about 45 megadalton, but negative in $Ser{\acute{e}}ny$ test.

• 식물병연구
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• 제21권2호
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• pp.103-106
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• 2015

벼 도열병은 벼의 조직에 따라서 잎, 마디, 목, 그리고 이삭의 병징에 의해 특성화된다. 심각한 수량 손실이 잎 도열병 보다는 목도열병과 이삭도열병이 원인이 됨에도 불구하고, 분리된 균주의 병원력 검정은 목과 이삭 대신 잎에서 수행되었다. 이 연구에서 우리는 목과 이삭 도열병을 위한 병원성 검정 방법을 개발하였다. 병원력 검정을 위해, 잎, 목, 그리고 이삭 도열병으로 부터 각각 3개의 대표균주를 선발하였다. 벼에 도열병균을 접종한 후 48시간 동안 고습도생장상에서 두었을 때, 24시간보다 목과 이삭에서 높은 발병률을 보였다. 잎 도열병 검정과 다르게, 목과 이삭에서의 전형적인 병반은 접종 14일 후 나타났다. 이 연구방법은 앞으로 벼 도열병의 벼 조직 별 병원성 검정방법을 위해 활용될 수 있을 것이다.

• 대한미생물학회지
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• 제35권4호
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• pp.317-324
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• 2000

Candida albicans is one of the most frequently isolated fungal pathogens in human. Recently, the prevalence of candida infection has markedly increased, partially due to the increase of immunocompromised hosts. Proposed virulence factors of the pathogenic Candida are the ability to form hyphae to adhere to epithelial cell surfaces, and to secrete acid proteinases and phospholipases. We measured the relative cell surface hydrophobicity (CSH) and the ability of proteinase production (PROT), phospholipase production (PLase), adherence to host epithelium (ADH), and hyphal transition (Germ). The relative risk of virulence factors was analyzed by lethality test in murine model of hematogeneously disseminated candidal infection. According to Cox's proportional hazard analysis, the statistically significant virulence factors were PROT, ADH, and CSH. PROT was the highest risk factor of them. To evaluate the applicability for the diagnosis and treatment of Candidiasis, we examined the protective effect of the active and passive immunizations with the materials purified from virulence factors and antibodies to them in Candia-infected mice model. The mean survival times of active and passive immunized groups were slightly longer than those of non-immunized groups.

• 한국응용곤충학회지
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• 제13권1호
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• pp.32-32
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• 1974