• 미생물학회지
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• 제12권2호
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• pp.59-68
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• 1974

With an aim to disclose causal factors scably grains intoxications, the screening of toxic Fusaria and the detection of toxic priniciples were performed in respect of cultured cells bioassay with HeLa cells, skin-necrotizing effect, histopathological investigation and also chromatographic analysis sith following results ; 1. Among the fungi, Fusarium sp. F-27, F-63 and F-61 were highly toxic to mice, causing liver injury characterized necrosis and inflammation. 2. HeLa cell culture bioassay demonstrated that the cell of the isolated strains of Fusaria were suspected to produce toxic material (Fusarenon-X). 3. The culture filtrates of Fusarium nivale Fn-2B, F-27, and F-63, were injected subcutaneously, and caused inflammation followed by crust on the skin ICR-mice. 4. The observation method of skin-necrotizing effect to the mice can be used to the screening to the toxin-producing fungi isolated from many fusarial contaminations.

• 미생물학회지
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• 제54권3호
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• pp.214-221
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• 2018

Clostridium difficile infection (CDI) is a rapidly emerging infection that may have devastating consequences. Prompt and accurate diagnosis is crucial for management and control. The aim of this study was to determine the incidence of C. difficile associated diarrhea among hospitalized patients, and to compare different diagnostic laboratory methods for detection of toxin producing strains in clinical specimens. The study was conducted at a university hospital in Cairo during the period from May 2013 till June 2015. Subjects were under antibiotic therapy and presented with hospital-acquired diarrhea. Four hundred and sixty-five stool specimens were processed by different microbiological methods. C. difficile was recovered in culture in 51 of stool specimens. Of these, 86.3% to 98% were positive for toxin production by 2 different methods. This study showed that antibiotic intake is the major risk factor for development of hospital-acquired diarrhea. We evaluated different microbiological methods for diagnosis of C. difficile. We recommend the use of toxigenic culture as a gold standard for microbiological diagnosis of C. difficile.

• 대한의생명과학회지
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• 제26권3호
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• pp.210-216
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• 2020

The purpose of this study was to evaluate GDH & Toxin (GDT) tests for the identification of the presence of Clostridioides difficile (C. difficile) as well as to detect whether any toxin was present in the feces of patients suspected of diarrhea associated with C. difficile. Data related to the results of toxin and culture (TC) tests and GDT tests conducted on patients with diarrhea and suspected CDI between January 2017 and august 2018, positive test rates, patient ages and sexes, whether the patients were hospitalized, and turnaround time (TAT) were analyzed retrospectively. Of the 7,554 total tests conducted for CDI diagnosis, 1,010 TC tests (14.9%) were positive, while 92 GDT tests (12.0%) were positive. Of these positive cases, 815 (80.7%) identified through TC test and 80 (87%) identified through GDT test were inpatients. also, among the patients with positive test results, 497 (49.2%) diagnosed through TC test and 45 (48.9%) diagnosed through GDT test were aged 61 years or older. The total time required to complete a TC test was 83.6 hours, while the time required for a GDT test was 11.2 hours, equating to an approximately three-day difference between the two tests. The detection of toxin-producing C. difficile is important in CDI diagnosis, but the commonly used Enzymeimmunoassay (EIA) toxin tests with low sensitivity result in delayed CDI diagnosis time. Therefore, primary screening tests for CDI diagnosis using the GDT method and secondary tests using additional methods are considered most effective.

• 대한미생물학회지
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• 제10권1호
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• pp.39-58
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• 1975

These studies were carried out to detect the presence of mycotoxin producing fungi in various kind of grains and foodstuffs in Korea. The experiments were divided into three parts: bacteriologic, toxicologic and electron microscopic studies. The results were summarized as follows: 1. From the 133 various samples, 426 colonies of fungi were isolated. In 405 of 426 colonies, it was possible to identify 17 genera. Among the identified strains, the predominant genera were Penicillium, Aspergillus and Alternaria. 2. In cytotoxicity test, 20 strains showed mild to severe toxic effects in mice and 24 strains showed toxic effects on HeLa cells among the 107 strains of experiments. 3. In electron microscopic studies of liver cells from animal which had been treated with toxin like substances, the liver cells showed the cytoplasmic changes: dilatation of endoplasmic reticulum, swelling of mitochondria, disappearance of mitochondrial cristae, increased number of lipid and glycogen particles. Nucleus and nuclear envelope alterations were also noted. 4. In fine structure of HeLa cells treated with culture filtrates of mycotoxin producing fungi and experimental strains had been noted a certain specific changes induced by culture filtrates. These alterations showed the disappearance of golgi complex, endoplasmic reticulum vacuolization and mitochondrial changes. 5. As a mass screening, the cytotoxicity tests of HeLa cells and histopathologic study of mice liver cells treated with toxin-like substances, employed are feasible to detect mycotoxin producing fungi.

• 한국식품위생안전성학회지
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• 제13권3호
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• pp.313-317
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• 1998

본 연구는 한국 전통 된장과 간장 및 메주등에서 주된 상재균으로 나타나는 B. subtilli가 Aspergillus parasicus의 성장과 발암물질(Aflatoxin) 생성에 미치는 영향을 관찰하기 위하여 수행되었다 변형 APT 배지를 사용하여 $30^{\circ}C$에서 12일 동안 B. subtilis KCCM 11316과 Aspergillu parasiticus ATCC 15517를 단독 배양(대조군) 및 혼합 배양하고 그 성장과 배양물의 변화를 경시적으로 관찰하였으며 HPLC에 의하여 aflatoxin을 분석하였다. 혼합 배양시에는 곰팡이의 건조 균체량이 배양 직후로부터 배양 말기에 이르기까지 현저하게 억제되었으며, 배양 말기에 단독 배양시보다 85.3% 감소되었다(p<0.01). Aflatoxin의 생성량도 배양 말기에 대조군에 비하여 50%이상 감소되었다(p<0.05). 이로부터 Bacillus subtilis는 메주 및 간장과 된장에 있어서 유해 곰팡이의 생육과 aflatoxin 생성을 주도적으로 억제하는 것을 알 수 있다. Aflatoxin 생성에 대한 억제 효과는 곰팡이의 성장에 대한 억제 효과보다 낮게 나타났으나 메주 중에는 다른 발효 관련 세균들이 함께 존재하는 바, 이들에 의한 억제적 영향도 기대된다.

• 한국미생물·생명공학회지
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• 제2권1호
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• pp.19-27
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• 1974

식품중에서 분리한 Penicillium 속에 대하여 Hela cell과 ICR-mouse를 이용한 독성 여부를 관찰하였던 바 다음과 같은 결론을 얻었다. 1. 총 실험균주 Penicillium 속 31주 가운데 Helacell에 대하여 독성을 나타내는 균주는 9주(P-32, P-47, P-56. P-63, P-66, P-67, N$_1$-3, N$_1$-12 및 RC-8)이었다. 2. 실험균주중 ICR-mouse에 대하여 독성 및 병변을 유발한 것은 31주 중에서 7주(P-32, P-63, P-66, P-67, $N_2$-1 N$_1$-2 및 RC-8)이였다. 3. Hela cell을 이용하여 진균의 유독성 여부를 screering 하는것은 가능한 방법이라고 생각된다.

• 대한미생물학회지
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• 제12권1호
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• pp.33-49
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• 1977

These studies were carried out to detect the presence of mycotoxin fungi and detoxification of toxins in various kinds of grain and foodstuffs in Korea. The experiments were divided into three parts: mycologic, toxicologic and electron microscopic study. The resuIts were summarized as follows: 1. From the 210 various, samples(local grains, 150 samples; rice-cakes, 50 samples; meju, 10 samples), 1,205 colonies or fungi were isolated. In 1,127 of 1,205 colonies, it was possible to identify 21 genera. Among the identified strains, the predominant genera were Aspergillus sp.(28.5%), Penicillium sp.(27.1%) and Mucor sp.(7.8%). 2. In cytotoxicity test on HeLa cells, 25 strains showed severe toxic effects among the 240 strains of experiments. 3. In histopathologic test on mice, 21 strains showed severe toxic effect to mouse liver cells among the 240 tested strains. 4. In electron microscopic studies of HeLa cells and mouse liver cells from animal which had been treated with crude toxin, the liver cells showed the cytoplasmic change: dillatation or vacuolization of endoplasmic reticulum, swelling of mitochondria and disappearance of mitochondrial cristae, increased number of lipid and glycogen particles. Nucleus and nucelar envelope alterations, were also noted. 5. In the detoxification study with ultraviolet irradiation, 90% of the toxic substances were denatured by the ultraviolet light irradiation for 24 hours. 6. As a mass screening, the cytotoxicity test of HeLa cells and histopathologic study of mice liver cells treated with culture filtrates, employed and feasible to detect mycotoxin producing fungi.

• 한국동물위생학회지
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• 제19권2호
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• pp.126-138
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• 1996

Lungs from 109 slaughter pigs with gross lesions indicating enzootic Pneumonia of pigs(EPP) and 16 grossly normal lungs, all originating from seven different herds, were subjected to microbiological examinations. The microbiological studies were included both bacterial and mycoplasmal culture. From lungs of 125 slaughter pigs, 87.2% pigs were pneumonia lesions alone or complexly Mycoplasma spp., pasteurella multocidu(p. multocida), Streptococcus spp., and Actinobacillus pleuropneumoniue(A. pleuropneumoniae) were detected in 39.4%, 42.2%, 13.8%, and 3.7% of the pneumonic lungs, respectively. P. multocida was the most frequently isolated organism in pneumonic lungs. Mycoplasmas not isolated organism in 33.9% the pneumonic lungs even If [here are gross lessions mycoplasmas. The amounts of pneumonia in lungs with Mycoplasma spp. alone, a concurrence of Mycoplasma spp. and P. multocida, p. multocida alone, a concurrence of P. multocida and A. pleuropneumoniae, and a concurrence of Mycoplasma spp. and A pleurdpneumoniae were 10.1%, 22.7%, 18.7%, 25%, and 30%, respectively These findings indicated that p. multocida might be involved in the pathogenesis of pneumonia in slaughter pigs. Mycoplasma spp. was also, in this study, associated with higher frequency of pneumonia. The frequency of pigs snout lesion grade 0∼5 inclusive were 27.2%, 28%, 19.2%, 16%, 6.4%, and 3.2% from 125 slaughter pigs. 32(25.6%) pigs were positive and 13~30% in the pigs from seven herds were found to be infected with atrophic rhintis (AR). A total of 46 P. multocida strains In pneumonic lungs were further characterized by capsular serotyping and testing for production of dermonecrotic toxin. 42(91.3%) of strains were capsular A and 4(8.7%) were type D. Out of the type A and type D strains, 86% and 75% were toxigenic, respectively.

• Journal of Microbiology and Biotechnology
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• 제31권7호
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• pp.999-1010
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• 2021

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment. They are highly toxigenic and carcinogenic. Probiotic bacteria isolated from fermented foods were tested to check their ability to degrade and/or detoxify PAHs. Five probiotic bacteria with distinct morphologies were isolated from a mixture of 26 fermented foods co-cultured with benzo(a)pyrene (BaP) containing Bushnell Haas minimal broth. Among them, B. velezensis (PMC10) significantly reduced the abundance of BaP in the broth. PMC10 completely degraded BaP presented at a lower concentration in broth culture. B. velezensis also showed a clear zone of degradation on a BaP-coated Bushnell Haas agar plate. Gene expression profiling showed significant increases of PAH ring-hydroxylating dioxygenases and 4-hydroxybenzoate 3-monooxygenase genes in B. velezensis in response to BaP treatment. In addtion, both live and heat-killed B. velezensis removed BaP and naphthalene (Nap) from phosphate buffer solution. Live B. velezensis did not show any cytotoxicity to macrophage or human dermal fibroblast cells. Live-cell and cell-free supernatant of B. velezensis showed potential anti-inflammatory effects. Cell-free supernatant and extract of B. velezensis also showed free radical scavenging effects. These results highlight the prospective ability of B. velezensis to biodegrade and remove toxic PAHs from the human body and suggest that the biodegradation of BaP might be regulated by ring-hydroxylating dioxygenase-initiated metabolic pathway.

• 미생물학회지
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• 제31권4호
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• pp.312-317
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• 1993

강원도와 남부지방에서 각각 옥수수와 보리를 채집하여 두 곡류로 부터 총 110 균주의 Fusatium graminearum을 분리한 후 쌀배지에서의 trichothecene과 zearalenone(ZEA)의 생성능을 측정하였다. 옥수수로 부터 분리한 51개의 F. graminearum 균주중 trichothecene 생성빈도는 deoxynivalenol(Don)이 64.5%, 3-acetyldeoxynivalenol (3-ADON)이 7.8%, 15acetyldeoxynivalenol (15-ADON)이 33.3%, nivalenol(NIV)이 21.6%, 4-acetylnivalenol (4-ANIV)이 13.7%였다. DON을 생성하는 균주들은 3-ADON보다는 15-ADON을 동시에 생성하였다. 한편, 보리로부터 분리한 59개의 F. graminearum 균주중 trichothecene 생성빈도는 NIV가 71.2%, 그리고 4-ANIV가 61.0%였으며, 한 균주만이 DON과 3-ADON을 동시에 생성하였다. 옥수수로부터 분리한 균주들의 ZEA의 생성빈도와 생성량은 각각 32.0%, 71㎍/g였으며, 보리로부터 분리한 균주는 각각 29%, 745㎍이었다. 이와같이 우리나라 강원도지방과 남부지방의 F. graminearum 균주들의 trichothecene 생성양상은 지역적인 큰 차이를 나타내었다.