• Journal of Microbiology
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• 제44권5호
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• pp.537-547
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• 2006

This study was designed to determine whether or not Vibrio vulnificus metalloprotease VvpE can promote iron uptake via the proteolytic cleavage of human hemoglobin. We found that V. vulnificus utilized hemoglobin as an iron source more efficiently via the vulnibactin-mediated iron-uptake system than via the HupA-mediated iron-uptake system and, of the proteases produced by V. vulnificus, VvpE was found to be the only protease capable of destroying hemoglobin. However, VvpE expression, on both the transcriptional and protein levels, was suppressed in iron-limited media. However, vvpE transcription, but not extracellular VvpE production, was reactivated by the addition of hemoglobin or inorganic iron into iron-limited media. Moreover, vvpE transcription began only in the late growth phase when V. vulnificus had already consumed most of the iron for growth. In addition, neither vvpE mutation nor in trans vvpE complementation affected the ability of V. vulnificus to acquire iron or to grow in iron-limited media or in cirrhotic ascites containing hemoglobin. Hemoglobin added into iron-limited media was not destroyed, but gradually formed an insoluble aggregate during culture; this aggregation of hemoglobin occurred regardless of vvpE mutation or complementation. These results indicate that VvpE is not required for efficient iron uptake from hemoglobin. On the contrary, hemoglobin or iron is required for efficient vvpE transcription. In addition, a discrepancy exists between vvpE transcription and extracellular VvpE production in iron-limited media containing inorganic iron or hemoglobin, which suggests that additional unknown posttranscriptional events may be involved in the extracellular production of VvpE.

• Journal of Microbiology and Biotechnology
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• 제25권2호
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• pp.302-306
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• 2015

VvpM, one of the extracellular metalloproteases produced by Vibrio vulnificus, induces apoptotic cell death via a pathway consisting of ERK activation, cytochrome c release, and activation of caspases-9 and -3. VvpM-treated cells also showed necrotic cell death as stained by propidium iodide (PI). The percentage of PI-stained cells was decreased by pretreatment with Necrostatin-1, indicating that VvpM-mediated cell death occurs through necroptosis. The appearance of autophagic vesicles and lipidated form of light-chain-3B in rVvpM-treated cells suggests an involvement of autophagy in this process. Therefore, the multifarious action of VvpM might be one of the factors responsible for V. vulnificus pathogenesis.

• 한국미생물·생명공학회지
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• 제36권1호
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• pp.6-11
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• 2008

방사선 조사 후에 생존한 병원성 미생물의 안정성을 연구하기 위하여 패혈증을 일으키는 Vibrio vulnificus ATCC 29307의 병원성 인자인 metalloprotease (vvp) 유전자의 발현과 효소 활성의 변화를 감마선 조사 후에 시간대별로 확인하였다. V. vulnificus는 다른 병원성 미생물들에 비하여 비교적 높은 방사선 감수성을 보였으며 방사선 조사 직후 유도기를 거친 후에 성장이 다시 시작되었다. 감마선을 조사하였을 경우 vvp 유전자의 발현은 비조사구에 비하여 $3{\sim}6$시간 정도 빨리 유도되었으나 총 metalloprotease의 활성은 감소하였다. 또한, vvp 유전자의 발현이 최대로 증가한 시점에서 metalloprotease의 활성을 비교한 결과 감마선이 조사된 균의 경우 감마선이 조사되지 않은 균에 비하여 약 $70{\sim}80%$ 수준으로 생산량이 감소하는 것을 알 수 있었다. 결론적으로, 감마선 조사 후 생존한 Vibrio vulnificus에서 병원성 인자 (vvp)의 발현 및 활성은 증가하지 않았으며 본 연구결과는 감마선 조사 식품의 미생물학적 안정성을 보여주는 기초 자료중의 하나로 활용될 수 있을 것으로 판단된다.

• 한국환경과학회지
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• 제19권10호
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• pp.1187-1201
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• 2010

The formation and development conditions of the cloud streets over the yellow sea by the Cold Surge of Siberian Anticyclone Expansion which produce the heavy snowfall events over the southwestern coast, Honam District of the Korean peninsula, has been investigated through analyses of the three dimensional snow cloud structures by using the CAPPI, RHI, VAD and VVP data of X-band Radar at Muan Weather Observatory and S-band Radar at Jindo Weather Station. The data to be used are obtained from January 04, 2003, when heavy snow storm hits on Gwangju and Honam District. The PPI Radar images show that the cloud bands distribute in perpendicular to the expansion direction of the high pressure and that the radius of cloud cells is about 5~8 km with 20~30 dBz and distance between each cell is about 10 km. And but the vertical Radar images show that the cloud street is a small scale convective type cloud within height of about 3 km where a stable layer exists. From the VVP images, the time period of the high pressure expansion, the moving direction and development stages of the system are delineated. Finally, the vertical distribution of wind direction is fairly constants, while the wind speed sheer increases with altitude to 3 km.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2020년도 정기학술대회 발표논문집
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• pp.220-220
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• 2020

Astaxanthin, a natural carotenoid component of shrimp, has been used as a food additive for the treatment of various diseases, but a functional role of Astaxanthin Nanosphere (AN) in the regulation of intestinal mucin (Muc) 2 production during bacterial infection has not described yet. In this study, we have investigated the effect of AN prepared from astaxanthin during Muc2 repression elicited by the Gram-negative bacterium V. vulnificus in human gastrointestinal epithelial (HT-29) cells. AN significantly inhibited the level of ROS production and PKC activation in recombinant protein (r) VvpE-stimulated HT-29 cells. Moreover, AN inhibited the PKC-mediated phosphorylation of extracellular signal-regulated kinase and nuclear factor-kappa B responsible for region-specific hypermethylation in the Muc2 promoter in rVvpE-treated HT-29 cells. In the mouse models of V. vulnificus infection, treatment with AN maintained the level of Muc2 expression in the intestine. On the basis of these results, we suggest that AN blocks the hypermethylation of the Muc2 promoter to restore the level of Muc2 production in HT-29 cells infected with V. vulnificus.

• 미생물학회지
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• 제41권3호
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• pp.168-176
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• 2005

갯벌 퇴적물에 존재하는 병원성 해양미생물인 Vibrio vulnificus를 신속하고 정확하게 검출하기 위해 PCR, Southern hybridization 방법과 real-time PCR을 수행하여 검출 민감도를 비교하였다. 갯벌 퇴적물로부터 bead beater를 이용한 물리적 방법으로 DNA 조추출액을 얻고 상용화된 키트 (Geneclean turbo Kit)를 이용하여 부식물질(humic substances)을 제거하였다. 병원성에 관련된 3 종의 유전자(hemolysin, vvhA; phosphomannomutase, pmm; metalloprotease, vvpE)를 대상으로 설계한 프라이머 셋을 동시에 사용하는 multiplex PCR 방법과 Southern hybridization과 병행한 방법(PCR/Southern hybridization)을 수행하였다. Real-time PCR은 hemolysin 유전자(vvhA)에 특이한 프라이머와 TaqMan 탐침을 사용하였다. 전처리하지 않은 갯벌 퇴적물의 경우, PCR/Sourthern hybridization과 real-time PCR 방법의 검출 민감도는 퇴적물 1 g 당 약 $10^2$ 개의 세포 수준이었다. 농후처리액(APW; alkaline peptone water)으로 $35^{\circ}C$에서 $2{\~}3$시간, 8시간 중균 배양할 경우 갯벌 퇴적물 1 g 당 $2{\~}10$개 세포가 존재할 때 PCR/Southern hybridization 방법과 real-time PCR 방법으로 각각 검출할 수 있었다. 전처리 과정을 포함하여 real-time PCR은 $6{\~}7$시간, PCR/Sourthern hybridization은 약 36시간이 소요되었다.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.1021-1026
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• 2003

Numerous secreted and cell-associated virulence factors have been proposed to account for the fulminating and destructive nature of Vibrio vulnificus infections. Among the putative virulence factors are an elastase, elastolytic protease, and a cytolytic hemolysin. Effects of the elastase on the hemolysin were assessed by evaluating changes of hemolytic activities either in the presence or absence of the protease. Although hemolytic activity in the culture supernatant was lowered by the purified elastase added in vitro, the cellular level of hemolytic activity was unaffected by the mutation of vvpE encoding the elastase. Growth kinetic studies revealed that hemolysin reached its maximum level in the exponential phase of growth, and the elastase appeared at the onset of the stationary phase. These results have provided insight into the regulation of virulence factors: temporally coordinate regulation of virulence factors is essential for the overall success of the pathogen during pathogenesis.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.442-442
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• 2012

PEDOT[Poly(3,4-Ethylenedioxythiophene)]박막의 제작은 산화촉매제를 이용한 기상중합(Vapor Phase Polymerization)방법을 통해 최근 활발히 연구되어 지고 있다. 기상중합된 PEDOT박막의 특성은 박막의 중합의 정도와 성장 형상에 따라 그 특성이 크게 좌우된다. PEODT박막의 효율적인 중합에 있어 산화촉매제의 균일한 도포는 매우 중요하다. PEDOT의 효율적인 중합과 균일도포를 위해 산화촉매제에 DUDO와 PEG-PPG-PEG를 첨가한 혼합용액을 제작 VPP방법을 통해 PEDOT박막의 제작을 시도하였다. 그 결과 spin-coating 시 산화촉매 혼합용액의 균일한 도포가 관찰 되었으며 산화촉매제만 사용하여 제작된 박막에 비해 전도도와 막질이 향상된 PEDOT박막이 제작되었다. 이러한 결과는 산화촉매용액에 첨가된 PEG-PPG-PEG와 DUDO의 영향으로 PEG-PPG-PEG는 oxdiant용액의 균일 도포를 도왔으며 Inhibitor로 작용하는 DUDO는 PEDOT성장에 있어 불균일 결정성장을 억제하여 조밀한 PEDOT 박막 성장을 도운 것으로 생각된다. PEDOT 박막의 특성평가에는 Field Emission-Scanning Electron Microscopy, 4-Pointprobe, Optical microscopy 등이 사용되었다. 이러한 고전도도의 PEDOT박막을 OTFT의 전극소재로 사용한다면 OTFT소자의 성능 향상에있어 크게 기여 할 것으로 기대된다.

• 한국수산과학회지
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• 제54권6호
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• pp.918-926
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• 2021

We isolated 28 Vibrio vulnificus strains from seawater and fisheries and investigated the positive rate of eight virulence genes. Additionally, we evaluated the susceptibility of these strains to 25 antimicrobials. The positive rates of fur, vvhA, tcp, rtxA, vcgC, viuB, vvp, and acfA were 100, 92.9, 92.9, 67.9, 64.3, 25.0, 14.3, and 7.1%, respectively. A disk diffusion susceptibility test revealed that, all the investigated strains had the highest resistance to amoxicillin and oxacillin, followed by that to streptomycin (96.4%), cefoxitin (92.9%), clindamycin (82.1%), amikacin (67.9%), vancomycin (46.4%), nalidixic acid (7.1%), penicillin G (7.1%), and ampicillin (3.6%). Moreover, they were susceptible to 10 other antimicrobials, including cefotaxime, chloramphenicol, erythromycin, gentamicin, and rifampicin. Notably, amoxicillin, oxacillin, and streptomycin had average minimum inhibitory concentrations of 132.6, 603.4, and 23.1 ㎍/mL against V. vulnificus, respectively. These observations provide new insights regarding the necessity for sanitation of commercial fisheries and can potentially, help reduce the risk posed by fisheries contaminated with bacteria resistant to antimicrobials.

• 생명과학회지
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• 제14권2호
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• pp.362-367
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• 2004

장염비브리오균의 숙주 내 감염을 일으키는 기작을 이해하기 위하여 세포외 효소 중의 하나인 콜라겐분해효소의 유전자가 불활성화된 돌연변이체를 제작하였다. 콜라겐분해효소의 유전자인 vppC 유전자에 항생제 내성 유전자인 nptII를 삽입하여 제작된 재조합 DNA를 suicide vector인 pDMS197에 클로닝하여 pVCM03이라 명명하였다. 재조합 suicide 플라스미드 pVCM03을 E. coli 7213에 형질전환하여 접합을 통하여 원 균주인 V. varahaemolyticus 04에 전달하였다. 전달된 pVCM03 유래의 재조합 vvpC::npfII DNA는 homologous recombination에 의해 wild-type allele와 교환되어 돌연변이체를 형성하게 되고, 돌연변이체는 10% sucrose가 함유된 TCBS 배지에서 선별되었다. Allele exchange는 PCR에 의한 증폭된 DNA의 크기 비교로 확인하였다. 돌연변이체인 V. parahaemolyticus CM은 원 균주와 비교하였을 때 약 4배정도 낮은 콜라겐 분해 활성을 나타내었고, vero cell을 이용한 MTT assay에서도 원 균주에 비하여 낮은 세포독성을 보였다.