• Journal of Microbiology and Biotechnology
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• 제26권2호
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• pp.263-269
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• 2016

Temperate phages have been suggested to carry virulence factors and other lysogenic conversion genes that play important roles in pathogenicity. In this study, phage TEM123 in wild-type Staphylococcus aureus from food sources was analyzed with respect to its morphology, genome sequence, and antibiotic resistance conversion ability. Phage TEM123 from a mitomycin C-induced lysate of S. aureus was isolated from foods. Morphological analysis under a transmission electron microscope revealed that it belonged to the family Siphoviridae. The genome of phage TEM123 consisted of a double-stranded DNA of 43,786 bp with a G+C content of 34.06%. A bioinformatics analysis of the phage genome identified 43 putative open reading frames (ORFs). ORF1 encoded a protein that was nearly identical to the metallo-β-lactamase enzymes that degrade β-lactam antibiotics. After transduction to S. aureus with phage TEM123, the metallo-β-lactamase gene was confirmed in the transductant by PCR and sequencing analyses. In a β-lactam antibiotic susceptibility test, the transductant was more highly resistant to β-lactam antibiotics than S. aureus S133. Phage TEM123 might play a role in the transfer of β-lactam antibiotic resistance determinants in S. aureus. Therefore, we suggest that the prophage of S. aureus with its exotoxin is a risk factor for food safety in the food chain through lateral gene transfer.

• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.425-429
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• 2003

Staphylococcus aureus is a major pathogen for cattle, causing various forms of subclinical and clinical mastitis and could be a causative agent of food poisoning, it produces various superantigenic exotoxins which have a great public health significance. A total of 72 S. aureus clinical isolates from dairy farms located in Kyunggi Province Korea were examined for the species identification by biochemical method, and for the detection of $\beta$-lactamase, enterotoxin and other exotoxins genes by PCR. The results of species identification by biochemical method agreed with those of PCR done with species specific primer STA-AU. $\beta$-lactamase is an enzyme closely associated with the resistance to antibiotic penicillin, which is an important means of treatment of mastitis, all the isolates were positive for the presence of genes encoding $\beta$-lactamase, which were reproduced in penicillin susceptibility disc assay. Six types of toxin genes, Staphylococcal enterotoxin (SE)A, SEB, SEC, SEE, toxic shock syndrome toxin (TSST-1) and exfoliative toxin A (ET A) were detected in 72 isolates by PCR associated genotypic method in this study, none of the isolates carried the genes for enterotoxin D (SED) and exfoliative toxin B (ETB). The occurrence rate of exotoxin genes rated as 12.5%, and the precision of the PCR identification results has been confirmed using the reference strains.

• 대한수의학회지
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• 제45권2호
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• pp.185-189
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• 2005

Actinobacillus pleuropneumoniae is the causative agent of a porcine contagious pleuropneumonia. Among several virulence factors including exotoxin (Apx toxins), LPS, transferrin-binding proteins, OMPs, and some proteases, Apx toxins have been major targets for the protection study. In this study, cloning and expression of A. pleuropneumoniae Apx I and Apx II toxin, which are produced by all highly virulent strains, were performed by Escherichia coli expression system. Genes coding Apx I and II toxin were amplified from the A. pleuropneumoniae serotype 5 genomic DNA using polymerase chain reaction and cloned to a prokaryotic expression vector, pRSET. Expression of the Apx I and Apx II coding sequences in E. coli resulted in the formation of insoluble inclusion bodies purified according to a denaturing purification protocol, which employs the use of guanidium. Recombinant proteins were purified using $Ni^{2+}$-charged resin affinity purification. This expression and purification system made it possible to produce Apx I and Apx II in large amounts for further immunologic studies.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 추계국제학술대회
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• pp.3-13
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• 2020

Pseudomonas aeruginosa is a ubiquitous gram-negative bacterium causing serious infections. The P. aeruginosa T3SS is a syringe-like apparatus on the bacterial surface, with 4 effector toxins: ExoS, ExoT, ExoY, and ExoU. Here, we investigated the effect of ExoS and ExoT of the T3SS of P. aeruginosa K strain (PAK). The type three secretion system (T3SS) is a major virulence system of Pseudomonas aeruginosa (P. aeruginosa). The effector protein Exotoxin S (ExoS) produced by P. aeruginosa is secreted into the host cells via the T3SS. For the purpose of screening the inhibitors with regard to ExoS secretion, we developed the sandwich-type enzyme-linked immunosorbent assay (ELISA) system. PAK clinical strains induce proinflammatory cytokine production through the T3SS, and this involves NF-κB activation in pneumonia mouse models. We tried to confirm the role of the NF-κB transcription factor in ExoS- and ExoT-induced pneumonia mouse models. pro-inflammatory cytokines induction in response to ExoS and ExoT infection relied on NF-κB activation. Our findings highlight the roles of natural poduct in inhibiting proinflammatory cytokine expression during ExoS and ExoT exposure in PAK infections, paving the way for a novel therapeutic approach for the treatment of pulmonary infections.

• Journal of Oral Medicine and Pain
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• 제38권4호
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• pp.325-331
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• 2013

보툴리눔 톡신은 신경독소로, 운동신경 말단부위에서 분비되는 아세틸콜린의 분비를 차단하여 근육의 위축을 유발하게 된다. 의학계 및 치의학계에서는 이를 이용하여 다양한 질환을 치료하는 것을 시도하고 있다. 치과영역에서는 저작근 수축, 심한 이갈이, 안면 틱, 구강안면 운동장애, 교근비대의 치료 등 과활성 근육성 질환을 치료하는 데 사용하고 있다. 악안면 영역에 보툴리눔 톡신을 주입하고 난 뒤 발생되고 있는 합병증으로는, 자연스럽지 못한 안면표정, 통증의 증가, 두통 등이 유발될 수 있다고 보고되고 있다. 본 증례에서는 교근부에 보툴리눔 톡신 주입 후 발생된 전방 개교합 증상에 대하여 보고하고자 한다.

• Journal of Microbiology and Biotechnology
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• 제16권7호
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• pp.1104-1110
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• 2006

Recombinant antibody-toxin is a bifunctional protein that binds and kills a target cell expressing a specific antigen on the surface of the cell, and its structure is chimeric, in which a toxin is fused to an antigen-binding domain such as scFv or Fab. Divalent antibody-toxin molecules showed higher cytotoxicities against cancer cell lines than monovalent molecules. However, the yields of the divalent molecules were very low. In this study, we introduced the CH2, CH3, or CH2-CH3 (=Fc) domain of antibody in the middle of the Fab-toxin between the hinge region of human IgG1 and the toxin domain to increase the yield. The covalently bonded dimer could be formed by three disulfide bridges from cysteine residues in the hinge region. The molecule with the CH3 domain showed about 3-fold higher dimerization yield than previously constructed Fab-toxin molecules, while maintaining the cytotoxic activity comparable to that of scFv-toxin. However, the introduction of CH2 or Fc domain to the same position showed little effect on the dimerization yield. We also observed that the introduction of the CH3 region made it possible to form noncovalently associated dimer molecules.

• Parasites, Hosts and Diseases
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• 제58권2호
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• pp.173-179
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• 2020

Leishmaniasis is a prevalent cause of death and animal morbidity in underdeveloped countries of endemic area. However, there is few vaccine and effective drugs. Antimicrobial peptides are involved in the innate immune response in many organisms and are being developed as novel drugs against parasitic infections. In the present study, we synthesized a 5-amino acid peptide REDLK, which mutated the C-terminus of Pseudomonas exotoxin, to identify its effect on the Leishmania tarentolae. Promastigotes were incubated with different concentration of REDLK peptide, and the viability of parasite was assessed using MTT and Trypan blue dye. Morphologic damage of Leishmania was analyzed by light and electron microscopy. Cellular apoptosis was observed using the annexin V-FITC/PI apoptosis detection kit, mitochondrial membrane potential assay kit and flow cytometry. Our results showed that Leishmania tarentolae was susceptible to REDLK in a dose-dependent manner, disrupt the surface membrane integrity and caused parasite apoptosis. In our study, we demonstrated the leishmanicidal activity of an antimicrobial peptide REDLK from Pseudomonas aeruginosa against Leishmania tarentolae in vitro and present a foundation for further research of anti-leishmanial drugs.

• The Korean Journal of Physiology and Pharmacology
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• 제6권4호
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• pp.225-233
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• 2002

Kanagawa hemolysin (KH), an exotoxin produced from Kanagawa phenomenon-positive Vibrio parahemolyticus, has been shown to possess various biological activities including hemolysis, enterotoxicity, cytotoxicity, and cardiotoxicity. The aim of this study was to investigate the effect of KH on the cardiovascular system and its mechanism, employing in vivo and in vitro experiments of the rat. Intracerebroventricular (icv) administration of 100 mHU KH produced a marked and continuous pressor effect (icv KH-pressor effect), and the icv pressor effect was not repeatable. However, intravenous (iv) injection of the same dose of KH induced a prominent depressor effect (iv KH-depressor effect). The icv KH-pressor effect was inhibited by acid-denaturation, while the iv KH-depressor effect was not. Simultaneous icv administration of the three agents (ouabain, diltiazem, or bumetanide: $10{\mu}g/kg$ each) significantly reduced the pressor effect. The icv KH-pressor effect was inhibited by treatment with iv phentolamine or chlorisondamine, but was not affected by iv candesartan. The iv KH-depressor effect was repeatable and was attenuated by treatment with iv NAME or methylene blue. In vitro experiments using isolated thoracic aorta, $10^{-6}$ M phenylephrine (PE) and 50 mM KCl produced a sustained contraction. In rings contracted with either agents, KH showed relaxant responses in a concentration- dependent fashion and the relaxation (KH-vasorelaxation) was not dependent on the existence of the endothelium. The KH-vasorelaxation in the endothelium-intact rings contracted by PE was abolished by methylene blue treatment. In summary, the present findings suggest that in the icv KH-pressor effect the cation leak-inducing action of KH is implicated, which leads to the increased central sympathetic tone, that the iv KH-depressor effect results from the vasorelaxation via NO-guanylate cyclase system, and that the KH-vasorelaxation is independent of the endothelium and the guanylate cyclase system is involved in it. In conclusion, the mechanism of KH producing the icv pressor effect may not be identical to that of KH producing the iv depressor effect.

• 한국잠사곤충학회지
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• 제24권2호
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• pp.55-72
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• 1983

가잠의 휴면성을 난각의 조직학적 특성을 보고자 난각층에 대한 전자현미경상을 관찰하였고 또한 난각의 물리화학적 특성에 대해서는 수분투과성, 염산투과성, 염색성 및 난각 구조단백질을 조사한 결과를 요약하면 다음과 같다. 1. 난각구조를 전자현미경으로 보면 뚜렷이 4층으로 되어 있으며, 또한 휴면난과 비휴면난 및 즉침난 사이에 구조적인 차이가 보인다. 즉 외층 밖에 또 다른 전자밀도가 낮은 얇은 층이 휴면난에는 존재하고 있으나 비휴면 및 즉침난에는 이 층을 볼 수 없다. 2. 산난후 20∼24시간째의 휴면난과 비휴면난 및 즉침난 사이에 난각염산투과성의 차이를 보면 휴면난에 비해 즉침난 및 비휴면난이 모두 투과성이 높았고 또한 난령이 지남에 따라 휴면난은 투과성이 떨어지는데 반하여 즉침난 및 비휴면난은 투과성이 높아졌다. 3. 휴면난의 ether 처리난은 무처리난에 비해 난각의 투과성이 변하는 것으로 보아 난각물질 중 ether 용출물이 존재한다. 4. 난각의 수분투과성도 염산투과성에 있어서와 같이 휴면난이 즉침난 및 비휴면난에 비해 수분투과성이 낮았다. 5. 가잠난각의 조직화학적 특성은 단백질과 당에 대한 염색성이 높아 난각에는 단백질과 당이 풍부하며 특히 지질에 대한 염색성은 거의 음성이나 내층으로 갈수록 진하게 염색되었다. 6. 누에의 난각점착물은 PAS-alcian 반응으로 보아 mucopolysaccharides이다. 7. 난각 구조단백질 중 SH단백질에 대한 전기영동상에 있어서 휴면난과 비휴면난 모두 2개의 band가 인정되나 비휴면난의 경우 이동거리가 빠른 band는 매우 흔적적이며 또한 영동거리도 원점으로부터 멀리 이동하여 두 처리간에 minor component에 차이가 보였다. 8. SH단백질에 대한 아미노산조성에 있어서는 휴면난 및 비휴면난 사이에 큰 차이를 인정할 수 없었고 난각단백질중 SH단백질의 구성아미노산에는 glycine이 가장 많고 cystine함량은 적었다. SI K-2 는 Penicillin, Ampicillin과 Cephalothin에 저항성을 나타냈고 ts-U171, A-N92와 A-N115는 이 세항생제에 민감성을 나타냈다. Temperature - sensitive돌연변이균주를 42$^{\circ}C$에서 24시간 배양후에 28$^{\circ}C$로 옮기어 배양한 결과 ts-U601, -U603, -U604와 -U171은 성장을 더 이상하지 않았다.ta-exotoxin을 생산했는데, 48시간 배양 배지 $m\ell$당 70$\mu\textrm{g}$을 분비한 균주는 BTK-1이고, BTK-37 균주는 $m\ell$당 88$\mu\textrm{g}$(6.1$\times$$10^{8}$ Cells/$m\ell$) BTK-35 균주는 $m\ell$당 81$\mu\textrm{g}$(5.2$\times$$10^{8}$ Cells/$m\ell$)을 생산했고. 그외는 모두 70$\mu\textrm{g}$미만이었다. 3. Beta-exotoxin과 B. thuringiensis 균체을 동시에 per os, interaperitoneal injection, subcuntaneous injection, nasal cavity inoculation, intracerebral injection을 120시간 처리했어도 치사효과를 나타내지 않았다.삼각호마법 and Japan#s 병음한자변환방식 have prospect to be prevalent. The following suggestions can be made from these results, 1) All the

• 구강회복응용과학지
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• 제37권2호
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• pp.61-72
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• 2021

아름다운 미소는 좌우 대칭을 이루며 2 - 3 mm 치은을 보이는 상태를 일컫는다. 과다한 치은노출은 "거미 스마일"로 불리며 미적 장애로 인식되어 왔는데 원인으로는 지연맹출, 상악의 과도한 수직성장, 윗입술의 과도한 움직임 또는 짧은 윗입술로 등으로 보고되어왔다. 한편 클로스트리디움 보툴리눔 세균에서 생성된 외독소인 보툴리눔 독소는 투여된 부위의 신경말단에서 아세틸콜린의 유리를 막아서 근육 수축을 약화시켜 윗입술 과잉 운동으로 인한 치은과다노출증의 새로운 치료법으로 주목 받고있다. 현재까지 입술 주변 근육에 보툴리눔 독소를 주입하는 방법에 대한 많은 연구가 있었지만 아직 표준화 된 연구 방법과 치료 방법이 없어 치료 효과에 대한 논란이었다. 본 종설의 목적은 이러한 지난 과거의 연구들에서 적응증을 선택하기 위한 요소 및 보툴리눔 독소 치료의 효과를 분석하고자 한다. 특히 치은과다노출증에서 보툴리눔 독소 주사의 최적의 용량과 최적의 주사부위를 제시하고자 하였다.