• Journal of Microbiology and Biotechnology
• /
• 제20권7호
• /
• pp.1107-1113
• /
• 2010

Because conventional methods for detecting emetic-toxin-producing B. cereus are laborious and costly, various PCR assays, which are easy and cheap, have recently been reported. Therefore, this study estimated and compared the ability of various PCR assays to detect emetic-toxin-producing B. cereus strains isolated in Korea. The PCR assays were performed on 160 B. cereus strains, including 40 emetic-toxin-producing strains. Although the species-specific PCR assays were all shown to be highly specific, the sensitivities varied greatly. The accuracies of the primers were 97.5% (CER), 95.6% (EM1), 96.3% (RE234), 89.4% (CES), and 83.1% (Ces3R/CESR2). Moreover, the CER primer had a higher sensitivity (100%) than all the other primers tested, and a specificity of 96.7%. Thus, the CER primer was shown to be the most effective for screening the emetic-toxin-producing B. cereus strains tested in this study. However, the ability of these PCR assays to identify emetic-toxin-producing B. cereus should also be confirmed using other methods.

• Journal of Microbiology and Biotechnology
• /
• 제22권1호
• /
• pp.50-57
• /
• 2012

Phospholipase C-${\gamma}l$ (PLC-${\gamma}l$) expression is associated with cellular transformation. Notably, PLC-${\gamma}$ is up-regulated in colorectal cancer tissue and breast carcinoma. Because exotoxins released by Clostridium botulinum have been shown to induce apoptosis and promote growth arrest in various cancer cell lines, we examined here the potential of Clostridium difficile toxin A to selectively induce apoptosis in cells transformed by PLC-${\gamma}l$ overexpression. We found that PLC-${\gamma}l$-transformed cells, but not vector-transformed (control) cells, were highly sensitive to C. difficile toxin A-induced apoptosis and mitotic inhibition. Moreover, expression of the proapoptotic Bcl2 family member, Bim, and activation of caspase-3 were significantly up-regulated by toxin A in PLC-${\gamma}l$-transformed cells. Toxin A-induced cell rounding and paxillin dephosphorylation were also significantly higher in PLC-${\gamma}l$-transformed cells than in control cells. These findings suggest that C. difficile toxin A may have potential as an anticancer agent against colorectal cancers and breast carcinomas in which PLC-${\gamma}l$ is highly up-regulated.

• 한국균학회지
• /
• 제18권1호
• /
• pp.13-19
• /
• 1990

우리나라 옥수수산지로부터 분리한 Fusarium sporotrichioides 4균주의 밀배양체를 쥐에 경구투여하여 독성을 조사하였다. 총 4균주 중 3균주가 급여 3-4일 이내에 모든 쥐를 치사시켜 매우 높은 독성을 나타냈다. 독성 균주의 배양체를 박층크로마토그라피와 가스크로마토그라피 - 질량분석기로 분석한 결과 정선 지방에서 분리한 2균주가 T-2 독소와 관련대사물을 생성하였다. 본 보고는 F. sporotrichioides에 의한 T-2 독소의 생성을 우리나라에서는 처음으로 확인한 것이다.

• Genomics & Informatics
• /
• 제21권1호
• /
• pp.7.1-7.11
• /
• 2023

The gram-positive bacterium Listeria monocytogenes is an important foodborne intracellular pathogen that is widespread in the environment. The functions of hypothetical proteins (HP) from various pathogenic bacteria have been successfully annotated using a variety of bioinformatics strategies. In this study, a HP Imo0888 (NP_464414.1) from the Listeria monocytogenes EGD-e strain was annotated using several bioinformatics tools. Various techniques, including CELLO, PSORTb, and SOSUIGramN, identified the candidate protein as cytoplasmic. Domain and motif analysis revealed that the target protein is a PemK/MazF-like toxin protein of the type II toxin-antitoxin system (TAS) which was consistent with BLASTp analysis. Through secondary structure analysis, we found the random coil to be the most frequent. The Alpha Fold 2 Protein Structure Prediction Database was used to determine the three-dimensional (3D) structure of the HP using the template structure of a type II TAS PemK/MazF family toxin protein (DB ID_AFDB: A0A4B9HQB9) with 99.1% sequence identity. Various quality evaluation tools, such as PROCHECK, ERRAT, Verify 3D, and QMEAN were used to validate the 3D structure. Following the YASARA energy minimization method, the target protein's 3D structure became more stable. The active site of the developed 3D structure was determined by the CASTp server. Most pathogens that harbor TAS create a crucial risk to human health. Our aim to annotate the HP Imo088 found in Listeria could offer a chance to understand bacterial pathogenicity and identify a number of potential targets for drug development.

• 한국식품과학회지
• /
• 제44권4호
• /
• pp.460-466
• /
• 2012

T-2와 HT-2 독소는 type A trichothecene계 곰팡이독소에 속하는 식품 오염물질이나, 국내의 경우 기준치 설정과 분석법의 확립이 요구되고 있다. 본 연구에서는 T-2와 HT-2 독소의 분석법 확립에 도움이 되고자 옥수수와 현미 시료에 존재하는 carboxylesterase에 의한 T-2 독소의 탈아세틸화가 GC 및 HPLC에 의한 T-2와 HT-2 독소 분석치에 미치는 영향을 살펴보았다. 옥수수와 현미 시료로부터 제조된 carboxylesterase 조효소원에 의한 T-2 독소의 HT-2 독소로의 전환 정도를 살펴본 결과, 15분 이내에 84-86%의 HT-2 독소가 급격히 형성되었고, 30분 이후에는 93-95%로 증가한 후 일정하게 유지되었다. 시료에 존재하는 효소의 불활성화 여부가 분석치에 미치는 영향을 살펴보면, 효소를 불활성화 시킨 시료에서는 T-2 독소가 60-107% 검출되었고 HT-2 독소가 검출되지 않은 반면, 효소를 불활성화 시키지 않은 시료에서는 T-2 독소가 0-9% 검출되었고 HT-2 독소가 77-121% 생성되었다. 추출용매 및 추출방법에 따른 T-2 독소의 탈아세틸화를 살펴본 결과, methanol/water 80:20으로 추출한 경우에는 T-2 독소가 84-108% 검출되었다. 곰팡이독소의 동시분석을 위해 PBS로 1차 추출한 다음 methanol로 추출할 때, 효소를 불활성화 시킨 시료에서는 T-2 독소가 60-87% 검출되었고 HT-2 독소가 검출되지 않았다. 반면, 효소를 불활성화 시키지 않은 시료에서는 T-2 독소가 검출되지 않았고 HT-2 독소가 37-66% 생성되었다. 이러한 결과는 옥수수와 현미 시료에 존재하는 carboxylesterase에 의해 T-2 독소가 탈아세틸화되어 T-2와 HT-2 독소를 각각 정량분석할 때 분석치에 영향을 미칠 수 있다는 것을 시사한다.

• 생명과학회지
• /
• 제6권2호
• /
• pp.111-119
• /
• 1996

The production of interleukin-1(IL-1)and nitric oxide(NO) by cultured fibroblast cells of human nasal turbinate was revealed by biological assay respectively. The cells were incubated for various periods of time in the presence of staphyloccocal toxic shock syndrome toxin-1(TSST-1) and house dust mite(Dermatophagoides farinae, HDM), and the culture supernatants were harvested. There was a little difference in the activities of IL-1beta and the amount of NO produced by the cells when stimulated with 0.002-0.1$\mu$g/ml of TSSTO-1 and 0.02-1$\mu$g/ml of HDM. The shapes of the time course curves for the production of IL-1beta and NO by the cells were different. Groups stimulated with TSST-1 or HDM produced more IL-beta in 2 h than no exposure group(Control). A certain mixed group(TSST-1, 10ng+mite, 100 ng) continued to produce IL-1beta highly throughout the entire incubation period. The cells stimulated with TSST-1 or HDM produced more NO in 2 h and 6 h than that produced in the end of incubation(48 h). Also, the mixed groups were generally similar. There results suggest that induction of IL-1beta by a certain mixed condition(TSST-1+mite) in fibroblast cell in vivo may play a role in inflammation.

• Fisheries and Aquatic Sciences
• /
• 제1권2호
• /
• pp.153-158
• /
• 1998

Effects of cyclic (c) AMP and G-protein related reagents (3-isobutyl-l-methyxanthine (IBMX), Forskolin (FSK), cholera toxin (CTX), and pertussis toxin (PTX≫ on estradiol-17$\beta$ induced vitellogenin (VTG) induction were examined in primary hepatocyte cultures in rainbow trout Oncorhynchus mykiss. The addition of IBMX, FSK, or CTX to the incubation medium markedly increased VTG production, while PTX was not effective in stimulating the production. It is well known that cAMP regulates phosphorylation and dephosphorylation through mediation of protein kinase A. These results suggest that VTG production is highly dependent on cAMP state in hepatocytes because of its highly phosphorylated nature.

• 한국식품영양과학회지
• /
• 제34권6호
• /
• pp.924-928
• /
• 2005

2004년 4뭘 셋째 주에 수산시장에서 구입한 국내산의 패류 및 5, 7, 9월에 구입한 수입산 패류를 형광 HPLC에 의해 마비성 패류독의 특성을 분석하였다. 수입산 피조개에서는 마비성 패류독성분 중 Saxitoxin(STX), Decarbamoylsaxitoxin(dcSX), Gonyautoxin(GTX)-1,2,3,4,5, Cl 그리고 C2로 총 9개의 독성분이 검출되었다. 이 독성분 중에서 GTX1과 GTX4를 제외 한 나머지 성분들은 국내산 패류에서도 검출이 되었고, 패류 종류별 서로 다른 함량과 조성을 나타내었다. 뻘 속에서 사는 바지락과 백합의 Cl+2의 함량은$0.06\~0.56\;nmol/g$이 었다. 그러나 양식산 진주담치 와 굴에서는 더 높은 독성과 복잡한 독성분 조성을 나타내었다. 반면, 꼬막과 개조개의 독성분의 조성은 같은 종류의 시료라 할지라도 서로 다르게 검출되었다. GTX1과 GTX5는 수입산 가리비에서 더 높았고, STX는 다른 종류와 비교해서 수입산 피조개에서 더 높게 검출되었다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권14호
• /
• pp.5977-5981
• /
• 2015

Background: Worldwide, breast cancer is the most common cancer diagnosed among women and a leading cause of cancer deaths. The age of onset in Iran has become reduced by a decade for unknown reasons. Herceptin, a humanized monoclonal antibody, is a target therapy for breast cancer cells with over expression of HER2-neu receptors, but it is an expensive drug with only 20% beneficial rate of survival. This study introduces a novel approach to enhance the efficacy of this drug through immunoconjugation of the antibody to botulinum toxin. Decreasing the cost and adverse effects of the antibody were secondary goals of this study. Materials and Methods: Botulinum toxin was conjugated with Herceptin using heterobifunctional cross linkers, succinimidyl acetylthiopropionate (SATP) and sulfo-succinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC) according to the supplier's guidelines and tested on two breast cancer cell lines: SK-BR-3 and BT-474. Toxin and Herceptin were also used separately as controls. The cytotoxicity assay was also performed using the new bioconjugate on cultured cells with Alamar blue and a fluorescence plate reader. Results: Herceptin-Toxin bioconjugation significantly improved Herceptin efficacy on both breast cancer cell lines when compared to the control group. Conclusions: Toxin-Herceptin bioconjugation can be a potential candidate with increased efficiency for treating breast cancer patients with over expression of the HER2 receptor.

• 해양환경안전학회지
• /
• 제28권6호
• /
• pp.866-873
• /
• 2022

배양실험을 바탕으로 다양한 수온과 염분 조건에서 유독 와편모조류 Alexandrium pacificum (LIMS-PS-2611)의 생장속도와 마비성 패독(PST)의 변화를 조사하였다. A. pacificum는 수온 25℃, 염분 30 psu 조건에서 최대생장속도를 보였으며, 최대생장속도의 70% 이상은 수온 20~25℃, 염분 25~35 psu 구간에서 나타났다. A. pacificum 체내의 PST 주요성분은 N-sulfocarbamoyl계의 C1+2와 GTX5이었으며, 미량성분은 carbamate계의 neoSTX이었다. 수온과 염분에 따른 독함량의 변화를 보면, A. pacificum는 수온 20℃, 염분 30 psu의 조건에서는 비교적 낮은 독 함량을 보였다. 염분의 증가에 따라 독 함량이 증가하는 경향을 나타냈다. 그러나 최대생장속도를 보였던 수온과 염분 조건에서는 낮은 독 함량을 보였다. 따라서 6월 수온이 20-25℃ 범위일 때 발생하는 이매패류 독화현상은 A. pacificum에 의한 영향일 가능성이 있다.