• KSBB Journal
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• 제14권2호
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• pp.241-247
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• 1999

디프테리아는 Corynebacterium diphtheriae에 의해 발생되는 호흡기 질병으로 C. diphtheriae의 exo-toxin을 불활성화 시킨 toxoid 백신을 사용하여 예방해 왔다. 현재까지 국내에서는 정치배양 방법으로 디프테리아 toxin을 생산해 왔기 때문에 생산성과 품질에 한계가 있었으며, 이를 극복하기 위해 발효조를 이용한 발효조건 최적화에 대한 연구를 수행하였다. 디프테리아 toxin을 보다 효율적을 얻기 위한 배지로서 beef antigen이 함유되어 있지 않은 casein 유래의 NZ-Case를 선택하였다. 발효조에 의한 toxin 생성은 세포성장과 함께 증가하는 growh-associated form으로 나타났다. 최대의 세포성장과 toxin 생성은 초기 pH가 7.0인 배지에서 0.22vvm의 통기와 400rpm의 교반조건에서 얻을 수 있었다. 또한 최대의 toxin 생성을 위한 최적의 iron 이온의 농도는 0.3mg/L 이었으며, morgamcphospale의 첨가에 의한 calcium-phosphate 침전이 배지 내에 iron 이온의 농도조절을 위하여 요구되었다. 면역원성을 확인하기 위한 역가시험 결과 발효조 배양에서 얻은 toxoid는 4단위에서 모든 guinea-pigs가 생존하여 2단위인 정치배양 toxin에비해 월등히 우수한 것으로 판단되었다. 결국 발효조 배양으로 toxin을 생산할 경우 부작용이 적고 수율과 생산성 및 면역원성 이 우수한 toxid의 생산이 가능하였다.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.375-380
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• 2000

The preliminary screening of several cyanobacteria, using mice bioassay, reveale the production of a hepatotoxin by the cyanobacterium Scytonema sp. strain BT 23 isolated from soil. An intraperitoneal injection of the crude toxin (LD50 56 mg/kg body wt) from this strain caused the death of the mice within 40 min, and the anmals showed slinical signs of mice within 40 min, and the animals showed clinical signs of hepatotoxicity. The toxin was purified and partially characterized. The active fraction appears to be nonpolar in nature and shows absorption peaks at 240 and 285 nm. The purified toxin had an LD50 of TEX>$100<\mu\textrm{g}/kg$ body wt and the test mice died within 40 min of toxin administration. The toxin-treated mice showed a 1.65-fold increase in liver weight at 40 min and the liver color chnged to dark red due to intrahepatic hemorrhage and pooling of blood. Furthermore, the administration of the toxin to test mice induced a 2.58, 2.63, and 2.30-fold increse in the activity of the serum enzymes alanine aminotransferase, lactate dehydrogenase, and alkaline phosphatase, respectively. Further experiments with the 14C-labeled toxin revealed a maximum accumulation of the toxin in the liver. The clinical symptoms in the mice were similar to those produced by microcystin-L.R. These results suggest that hepatotoxins may also be produced in non bloom-forming planktonic cyanobacteria.

• 한국동물위생학회지
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• 제21권2호
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• pp.149-156
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• 1998

The present study was carried out to investigate the biochemical characteristics, antibiotic susceptibility and toxin(ST, LT, VT1.2 type) production test of 60 Escherichia coli isolated from diseased domestic animals in southern area of Kyungbuk province from April to December 1997. 1. The biochemical and cultural reaction were consistent with the classification criteria of Edwards and Ewing. 2. In antibiotic susceptibility test, 60 E coli showed highly susceptible to CL(96.7%), XNL(86.7%), AN(81.7%), SXT(61.7%), Lin(55%), GM(53.3%), KM(41.7%), N(41.7%), ENR(40%), AM(40%), CF(30%), 5(13.3%) and Te(11.7%), in order. 3. Sixty E coli isolates were multiful resistant to seven or more antibiotics incombination. 4. Three strains for 60 E coli were detected heat-labile enterotoxin(LT) and that's titers were 2, 8 and 16, respectively.

• KSBB Journal
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• 제14권2호
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• pp.248-254
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• 1999

본 연구에서는 디프테리아 toxin을 정제한 후 무독화하여 toxid를 생산하기 위하여 crude toxin을 2중 U.F를 통해 분자량 100.000이상의 단백질과 30.000이하의 배지 유래 단백질 및 색소를 제거한 결과 순도 1,300 Lf/mg PN의 toxin을 정제하였다. 이를 다시 DEAE-ion exehange chromatography를 통해 toxin을 정제한 후 무독화하여 순도 2,560 Lf/mg PN의 toxoid를 얻을 수 있었다. 이와 같이 생산된 디프테리아 toxoid는 동물 실험 결과 toxin으로 reversion이 발견되지 않았으며, 역가에 있어서도 crude toxin을 무독화한 후 정제한 toxoid와 비교하여 더 우수하였고 대한민국 생물학적 제제 기준에 규정된 성인용 디프테리아 백신 순도 기준 2,500 Lf/mg PN 이상에 적합하였다. 따라서 본 연구를 통해 성인용 디프테리아 백신의 생산 가능성을 확인하였다.

• 대한임상검사과학회지
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• 제37권1호
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• pp.27-34
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• 2005

Biochemical characteristics, enterotoxin production and antimicrobial susceptibility were determined for 30 strains of Bacillus cereus isolated from stool specimens of diarrhea patients at an university hospital in Chulabuk-do province. Positive rate for VP reaction and citrate utilization were lower, (33 % and 40 % respectively) while the rates of acid production from mannitol, arabinose, and xylose were higher (17 %, 13 % and 3 % respectively) than those obtained by other investigators. The enterotoxin gene was detected in 18 of 30 isolates (60 %) by PCR, and the toxin was detected from all of the toxin gene-positive isolates by RPLA test. The agar dilution test showed that all isolates were resistant to penicillin G and 73 % were to cephalothin, but all were susceptible to ciprofloxacin, clindamycin, erythromycin, fusidic acid, gentamicin, rifampin, teracycline and vancomycin. We conclude that B. cereus isolates producing acid from mannitol, arabinose and xylose exist, that PCR can be used to detect enterotoxin genes rapidly and accurately, and that this organism is susceptible to various antimicrobial agents though not penicillin G and cephalothin.

• 한국환경보건학회지
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• 제38권6호
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• pp.510-519
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• 2012

Objectives: This study was conducted in order to evaluate the microbiological contamination of the indoor air of the lunchrooms at child care centers and investigate the toxin genes and toxin production ability of food-borne pathogens. Methods: A total of 64 child care centers were sampled to test total aerobic bacteria, coliform bacteria, fungi, Staphylococcus aureus, Bacillus cereus and Salmonella spp. according to the Korea Food Code. All toxin genes of pathogens were detected using the Polymerase Chain Reaction method. The Sthaph. aureus enterotoxin was detected by a Staphylococcus aureus enterotoxin-reversed passive latex agglutination kit. The heamolysin BL (HBL) and non-heamolytic enterotoxin (NHE) produced by B. cereus were detected using a B. cereus enterotoxin-reversed passive latex agglutination kit and Bacillus diarrheal enterotoxin visual immunoassay kit, respectively. Results: The means of total aerobic bacteria and coliform bacteria were $1.91{\pm}1.84$ log CFU/plate and $0.47{\pm}0.62$ log CFU/plate, respectively. The mean of fungi also showed $0.59{\pm}0.71$ log CFU/plate. Among the pathogenic bacteria tested in this study, Staphy. aureus and B. cereus were detected in four (6.3%) and 21 (32.8%) out of 64 indoor air samples from lunchrooms in child care centers, respectively. All Staphy. aureus tested in this study possessed no toxin genes and did not produce enterotoxin. The detection rate of nheABC, hblCDA, entFM and ces toxin gene in B. cereus was 100, 57.1, 76.2 and 0%, respectively. B. cereus isolates were classified into four groups according to the presence or absence of toxin genes. The nheABC gene was the major toxin gene among B. cereus tested in this study. The HBL was detected in 11 out of 21 B. cereus isolates (52.4%) and three B. cereus isolates produced NHE (14.3%). Conclusion: The results indicated that the contamination by microorganisms in the indoor air of lunchrooms was unqualified to supply safe catering in child care centers. The ongoing control of indoor air quality is required.

• 미생물학회지
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• 제16권4호
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• pp.161-169
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• 1978

Escherichiae-like organisms were isolated from rectal specimens of 56 children who were either in preschool age or in elementary school. The isolated strains were subjected to tests to screen enteropathogens producing heat-labile enterotoxin and susceptibility test to various antibiotics by disc diffusion method on agar plates. Production of heat-labile enterotoxin by the strains was assyed in the sensitive and reproducible cultured adrenal tumor cell system. The assay was sterodogenesis of the cell in the presence of heat-labile enterotoxin. Among 56 strains, gave positive reaction in the test of toxin production. This meant that about 10% of the children population objected to the study harbored the toxigenic strain of enteropathogenes. Some of these toxigenic strains were resistant to the antibiotics employed in the test. This study suggested that considerable population in Korea may harbor entertoxigenic E. coli as a part of intestinal normal flora. The toxigenic strains which are resistant to antibiotics may bring issue of public health in the future.

• Journal of Periodontal and Implant Science
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• 제38권sup2호
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• pp.335-342
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• 2008

Purpose: Cytolethal distending toxin (CDT) considered as a key factor of localized aggressive periodontitis, endocarditis, meningitis, and osteomyelitis is composed of five open reading frames (ORFs). Among of them, the individual role of CdtA and CdtC is not clear; several reports presents that CDT is an AB2 toxin and they enters the host cell via clathrin-coated pits or through the interaction with GM3 ganglioside. So, CdtA, CdtC, or both seem to be required for the delivery of the CdtB protein into the host cell. Moreover, recombinant CDT was suggested as good vaccine material and antibody against CDT can be used for neutralization or for a detection kit. Materials and Methods: We constructed the pET28a-cdtC plasmid from Aggregatibacter actinomycetemcomitans Y4 by genomic DNA PCR and expressed in BL21 (DE3) Escherichia coli system. We obtained the antibody against the recombinant CdtC in mice system. Using the anti-CdtC antibody, we test the native CdtC detection by ELISA and Western Blotting and confirm the expression time of native CdtC protein during the growth phase of A. actinomycetemcomitans. Results: In this study we reconstructed CdtC subunit of A. actinomycetemcomitans Y4 and generated the anti CdtC antibody against recombinant CdtC subunit expressed in E. coli system. Our anti CdtC antibody can be interacting with recombinant CdtC and native CDT in ELISA and Western system. Also, CDT holotoxin existed at 24h but not at 48h meaning that CDT holotoxin was assembled at specific time during the bacterial growth. Conclusion: In conclusion, we thought that our anti CdtC antibody could be used mucosal adjuvant or detection kit development, because it could interact with native CDT holotoxin.

• 식물병연구
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• 제15권1호
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• pp.46-50
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• 2009

Cytochalasin E (CE) is a secondary metabolite secreted by Rosellinia necatrix, caused by white root rot, and has toxicity to apple as a toxin during disease progress. This study was conducted to demonstrate the relationship between the production of CE and its pathogenicity. CE producing isolates and non-producing isolates of R. nectatrix were isolated from the mycerial mat of diseased roots and was detected on that using a TLC and HPLC analysis and in vivo pathogenicity test. CE non-producing isolates were not pathogenic to apple roots and not detected CE by TLC and HPLC analysis. It was shown that the production of CE was related to the pathogenicity of R. nectatrix.

• 미생물학회지
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• 제40권4호
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• pp.286-294
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• 2004

1997년과 1998년 사이에 설사 증상을 보이는 돼지의 분변으로부터 총56균주의 Escherichia coli를 분리하여 이중 용혈성을 나타내는 38균주의 항생제 내성과 독소 생산능을 확인하였다. 항생제 한천 희석법으로 최소억제농도(minimal inhibitory concentration)를 측정한 결과 36균주$(94.7\%)$가 tetracycline에 대해 내성을 나타내었고, 27주$(71.0\%)$는 ampicillin에 내성, 26균주$(68.4\%)$는 chloramphenicol에 내성, 그리고 21균주$(55.2\%)$는 tri-methoprim에 내성을 나타내었으나, aztreonam, amikacin, norfloxacin에 내성을 나타낸 균주는 발견되지 않았다. 이중 4가지 이상의 항생제에 대해 내성을 가지는 다제내성(multiple drug resistance, MDR)을 보인 균주는 총 38 균주 중 21균주$(55.3\%)$였다. 또한 이중 디스크 시험법(Double Disk Synergy Test)을 수행한 결과 extended spectrum $\beta-lactamase$를 생산하는 균주는 없는 것으로 나타났다. 이들 중 가장 많은 수의 균주가 내열성 독소$(ST,89.5\%)$를 생산하였고, 다음으로 베로 독소(VT와 VTe, 각각$47.4\%$)와 이열성 독소$(LT,31.6\%)$를 생산하는 것으로 나타났다. 이 중에서 8균주$(21.0\%)$는 57만을 생산하였던 반면에 12균주$(31.6\%)$는 LT와 ST를 동시에 생산하였고, 13균주$(34.2\%)$는 ST, VT, VTe를 동시에 생산하였으며, 5균주$(13.2\%)$는 VT와 VTe를 동시에 생산하는 것으로 나타났다. 그러나 네 가지 독소를 동시에 생산하는 균주는 없었다. 또한 이 균주들은 매우 다양한 혈청형(serotype)을 가지고 있음이 확인되었다. 사람에 직접적인 유해성을 가지고 있는 지 확인하기 위해 사람 방광 유래의 T-24세포와 장내 표피 유래의 Caco-2세포에 대한 부착능을 시험하였을 때, 16균주$(42.1\%)$가 T-24방광 세포에, 그리고 17균주$(44.7\%)$가 Caco-2장세포에 대해 강한 부착능을 나타내었다. 특히 11균주$(28.9\%)$는 두 세포 모두에 강한 부착능을 가지고 있었다. Filter mating method를 수행하여 이들 균주들의 독소 생산 유전자와 항생제 내성 유전자가 사람에서 분리된 균주로 전달되는 것을 확인할 수 있었다. 본 실험의 결과는 설사 중상을 나타내는 돼지로부터 분리된 용혈성 E. coli의 독성과 세포 부착능력, 그리고 항생제 내성간의 상호 연관성을 보여주지 않았으나 동물 분리 세균의 항생제 내성과 독소 생산 능력이 유전자 전달을 통해서 뿐만 아니라 세균의 직접 접촉에 의해서도 인체로 전달될 수 있는 것을 보여주는 것이다.