• 한국식품위생안전성학회지
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• 제31권6호
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• pp.439-444
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• 2016

두 종류의 Cronobacter 선택배지(DFI agar, R&F agar)의 분유 및 건조호박 내 Cronobacter의 선택 분리능을 real-time PCR법과 함께 비교하였다. 분유에서의 Cronobacter 검출률은 세 가지 방법에서 유의적인 차이를 나타내지 않았으나(p < 0.05), 건조호박의 경우 R&F배지와 real-time PCR법이 DFI에서보다 유의적으로 높은 검출률을 보였다(p < 0.05). 배지 간 선택성에 있어서도, R&F 선택배지는 건조호박에서 DFI에 비해 유의적으로 높은 선택성을 나타냈다(p < 0.05). Real-time PCR 및 R&F배지의 사용은 분유뿐만 아니라, 건조 호박 등의 높은 경쟁세균총을 갖는 영유아식의 원료로 사용될 수 있는 식품군에서도 Cronobacter를 효과적으로 검출할 수 있는 방법으로 사료된다.

• BMB Reports
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• 제30권3호
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• pp.216-221
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• 1997

Changes in pathogenicity of old and successively-cultured isolates of Fusarium oxysporum f. sp. niveum have been observed and the concept that such cultures will become attenuated is generally accepted. However, the genetic basis for this phenomenon has not been studied. In an effort to identify a DNA marker closely linked to variations, DNA methylation was investigated both before and after the successive transfers of F. o. f. sp. niveum isolates on artificial media. A sector of mycelium in F. o. f. sp. niveum race 2 isolate (TXXID) which showed variation in pigmentation and colonial morphology occurred after 18 successive weekly transfers on potato dextrose agar (PDA). The sector characteristics were stable and did not change after more successive transfers. It was shown that DNA methylation preexists in ribosomal RNA gene (rDNA) of F. o. f. sp. niveum and that additional changes in DNA methylation occurred during successive culturing.

• Mycobiology
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• 제34권3호
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• pp.154-157
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• 2006

A fungal isolate collected from infected paprika (Capsicum annuum var. grossum) was characterized as Sclerotinia sclerotiorum based on its ability of sclerotium formation, physiological and molecular properties. When the isolate was grown on potato dextrose agar, oatmeal agar, and malt extract agar, it grew most well on PDA. Optimal temperature and pH for its growth were $25^{\circ}C$ and pH 7, respectively. The fungal isolate produced sclerotia on PDA within 10 days, and the color and shape of the sclerotia were similar to those of S. sclerotiorum. The ITS rDNA regions including ITS1 and ITS2 and 5.8S sequences were amplified using ITS1F and ITS4 primers from the genomic DNAs of the paprika isolate and other known pathogenic S. sclerotiorum isolated from different crops in Korea, and their nucleotide sequences were determined. Sequence comparison analysis showed the ITS rDNA of the paprika isolate shares 100% sequence identity with those of S. sclerotiorum isolated from red pepper, lettuce and a S. sclerotiorum isolate registered in GenBank DNA database. Neighbor joining analysis based on the ITS rDNA sequence revealed the paprika isolate has very close phylogenetic relationships with known Sclerotinia sclerotiorum isolates. This is the first report that S. sclerotiorum has been found associated with paprika rot in paprika growing countries.

• KSBB Journal
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• 제32권2호
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• pp.133-139
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• 2017

Rheum palmatum has traditionally been used as a preventive agent and medication against fever and infection. The aim of this study was to isolate and characterize an antibacterial substance from R. palmatum that is effective against bacterial vaginosis. A methanol extract from R. palmatum showed antibacterial activity against Lactobacillus vaginalis KC TC 3515, Chryseobacterium gleum KCTC 2904, and Sphingomonas paucimobilis KCTC 2834, which cause bacterial vaginosis. After extraction and pH control of the methanol extract from R. palmatum, we found that acidic and alkaline extracts did not show antibacterial activity. A neutral extract (50 mg/mL) displayed an inhibitory zone of 18 mm on a nutrient agar plate with C. gleum KCTC 2904. Fractions No. 11 and 12 among 41 fractions obtained by silica gel column chromatography produced inhibitory zones of 10 mm on nutrient agar plates with C. gleum KCTC 2904. $R_f0.15$ and $R_f0.17$ spots produced by TLC of fraction No. 11 showed antibacterial activity against C. gleum KCTC 2904. Isolation and purification of the peak at a retention time (Rt) of 9.427 min was achieved by HPLC of $R_f0.29spots$. The peak at Rt 9.427 min showed antibacterial activity against C. gleum KCTC 2904.

• Journal of Periodontal and Implant Science
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• 제33권2호
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• pp.149-158
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• 2003

The purpose of this study was to isolate and characterize the Fusohacrerium nucleatum (F. nucleatum) from subgingival plaque in Korean periodontitis patients. The subgingival plaque samples of periodontitis patient were collected with sterilized paper point. The paper point was put into reduced transfer medium and then immediately transferred to laboratory. The subgingival samples were diluted by 10,000 folds and plated on F. nucleatum-selective media agar plate. The plates were incubated at 37$^{\circ}C$ in an anaerobic chamber for 3 days. The violet-colored colonies were selected and subjected to further verification whether those are F. nucleatum or not. For further confirmation, 16S rRNA genes (rDNA) were cloned from each of bacterial clones and determined sequence of 16S rDNA. In this study, we found 17 distinct clinical isolates of F. nucleatum from subgingival plaque. The clinical isolates will be a useful in various studies in periodontology.

• Fisheries and Aquatic Sciences
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• 제15권1호
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• pp.83-89
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• 2012

Flavobacterium johnsoniae was isolated from farmed rainbow trout Oncorhynchus mykiss in Korea, and its biochemical and molecular characterization was determined. Yellow-pigmented bacterial colonies were isolated from 18 of 64 fish samples (28.1%) on trypticase soy agar plates, and their biochemical profiles were characterized by API 20E and API 20NE test kits. F. johnsoniae was identified by biochemical phenotyping of factors including rapid gliding motility, Gram-negative condition, oxidase- and catalase-positive status, Congo red absorption, nitrate reduction, ${\beta}$-galactosidase production, acid production from glucose, and gelatin and casein hydrolysis. PCR and subsequent sequencing of 16S rRNA confirmed that the yellow-pigmented colonies were most similar to F. johnsoniae. The alignment analysis of 16S rRNA sequences also showed that all 18 rainbow trout isolates had highly similar homologies (97-99% identity). One isolate was selected and named FjRt09. This isolate showed 98% homology with previously reported F. johnsoniae isolates, and in phylogenetic analysis was more closely grouped with F. johnsoniae than with F. psychrophilum, F. columnare, or F. branchiophilum. This is the first report on the occurrence and biochemical characterization of F. johnsoniae isolated from rainbow trout in Korea.

• 미생물학회지
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• 제46권1호
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• pp.109-111
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• 2010

다환 방향족 탄화수소(PAH; polycyclic aromatic hydrocarbon)는 발암성, 돌연변이 유발성, 유전독성을 지니기 때문에 인체위해성이 큰 물질로 알려져 있다. 기존 PAH 분해 미생물 탐색 방법중 독성이 강한 유기용매에 PAH를 용해시켜 미생물에 직접 분무하는 분무법, 미생물과 직접 혼합하는 한천중층법은 미생물 생장에 영향을 줄 뿐만 아니라, 특히 많이 쓰이는 분무법의 경우 분무되는 PAH의 양을 조절하기가 어렵고 멸균상태를 유지하기가 힘들다는 단점이 있다. 그래서 본 논문에서는 이와 같은 단점을 보완한 방법으로 승화법(Alley, Jeremy F. and Lewis R. Brown. 2000. Use of sublimation to prepare solid microbial media with water-insoluble substrates. Appl. Environ. Microbiol. 66, 439-442)을 도입하여 적용하였다. 그 결과 상용휘발유 및 태안유류유출지 시료로부터 분리한 350분리균주 중에서 7균주가 단일 PAH 또는 복수의 PAH 분해에 관여했다. 특히 Corynebacterium sp. SK20, Rhodococcus sp. TA24, Streptomyces sp. TA27은 시험한 pyene, phenanthrene, naphthalene에, Gordonia sp. H37는 pyrene, naphthalene에, Arthrobacter sp. S49는, naphthalene, phenanthrene에 활성이 있었다.

• Journal of Oral Medicine and Pain
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• 제34권4호
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• pp.353-362
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• 2009

본 연구는 편백 피톤치드에 의해 사멸되지 않는 구강 상주균을 분리하고, 이 분리된 세균이 구강 병인균에 대하여 어떠한 영향을 미치는지를 관찰함으로써 편백 피톤치드에 구강 내 세균에 대한 지속적인 이차적 효과를 구명한 실험적 연구이다. 이에 건강한 사람의 타액에 1% 피톤치드를 첨가하여 최종적으로 생존해 있는 200개의 구강 상주균을 확인하여 이를 분석한 후 이들이 치주질환과 입냄새의 중요한 원인균인 F. nucleatum에 대한 억제효과를 관찰하여 다음과 같은 결론을 얻었다. 1. 선택된 200개의 잔존 세균 중, 70개(35.0%)가 F. nucleatum을 억제하였다. 2. F. nucleatum을 억제하는 70개의 잔존 세균 중, Streptococcus salivarius가 41.3%(45/109), Streptococcus sanguinis가 28%.(7/25), Streptococcus mitis가 20%(3/15), Streptococcus parasanguinis가 33.3%(3/9), Streptococcus alactolyticus가 100%(8/8), Streptococcus vestibularis가 28.6%(2/7), Streptococcus sp.가 50%(2/4)로 나타났다. 결론적으로 피톤치드 처리 후의 잔존 세균이 F. nucleatum을 억제함으로써 피톤치드가 구강 건강, 특히 치주질환을 예방하거나 치료하는데 큰 역할을 할 수 있을 것으로 생각하며, 구강 상주균을 건강하게 유지시킨 채로 병인균 만을 억제시킨다는 차원에서 향후 구강내 유익균의 배양가능성을 실용화 할 수 있다고 생각한다.

• Mycobiology
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• 제31권3호
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• pp.166-172
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• 2003

Chemical analysis of salted fish was analyzed in 60 samples collected from various moloha markets in Sohag, Qena and Aswan Governorates, Upper Egypt. Moloha contained 52.9% water content, while organic matter content represented 71.79% of dry weight and 33.81%($338.12{\pm}8.64mg\;g^{-1}$) of fresh weight. Total salts and soluble salts represented 13.29% and 10.19%($132.88{\pm}7.65\;and\;101.93{\pm}5.76mg\;g^{-1}$ of fresh weight), respectively. pH values were more or less neutral. Mycological investigation of examined samples revealed that fifty-five fungal species and one variety belonging to 11 genera were identified. The fungal genera of highest occurrence and their respective number of species were Aspergillus(A. flavus, A. niger, A. fumigatus, A. montevidensis, A. ficuum, A. parasiticus and A. mangini) and Penicillium(P. citrinum, P. puberulum, P. aurantiogriseum and P. roquefortii). On the other hand, yeast represented 18.2% and 3.0% of total counts of fungi on Czapeks-dextrose agar and 15%NaCl-Czapeks-dextrose agar media, respectively. Samples were assayed for potential presence of mycotoxins. Ten out of 60 samples(16.7%) were proved to be toxic. It is the first record of mycotoxins contamination of salted fish in Egypt. The ability of 340 isolates of recovered fungi was screened for production of mycotoxins and extracellular enzymes.

• 대한수의학회지
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• 제44권3호
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• pp.399-405
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• 2004

Haemophilus somnus, Mycoplasma bovis and Pasteurella multocida were responsible for respiratory diseases in bovine. Methods for identifying these bacteria had poor sensitivity and specificity. In this paper, PCR assays were applied for rapid identification of H. somnus, M. bovis, P. multocida B:2 and P. multocida capsular types. The specific PCR products were amplified from H. somnus, but not from other bacteria. Ten-fold diluted H. somnus were mixed with P. multocida and then the mixed cultures were inoculated on agar plates. After incubation, PCR was performed with harvest from agar plates and could detect as few as 3.4 CFU/ml of H. somnus. The primers MboF and MboR produced an amplification product unique to M. bovis and sensitivity of PCR was as low as 100 pg of DNA. Only serotype B:2 of P. multocida, the causal agent of haemorrhagic septicemia in bovine, was specifically amplified in PCR among the 16 reference serotypes. The multiplex capsular PCR typing for P. multocida was produced the P. multocida specific product as well as the capsular serogroup-specific product. The present PCR assays should be useful for the rapid identification of bacterial pathogens from bovine respiratory diseases.