• 대한의생명과학회지
• /
• 제23권2호
• /
• pp.64-72
• /
• 2017

The formation of brown colonies due to phenol oxidase activity on classic agar media containing natural material extracts of Helianthus annuus or on medium containing L-3,4-dihydroxyphenylalanine has been used to identify Cryptococcus species complex. In this study, various natural materials were used to develop a modified medium and to identify five major serotypes of Cryptococcus species complex. Serotypes A, D, and A/D were pigmented on medium using Perilla frutescens var. japonica Hara (PerJ agar) after a three-day incubation. Serotypes B and C were pigmented on PerJ agar after four- and five-day incubations, respectively. Growth time and pigmentation of the five serotypes occurred more rapidly on PerJ agar than on the other media. In addition, colony morphology, size, and pigmentation were specific by serotype. In conclusion, PerJ agar should be used in clinic settings to identify Cryptococcus species complex and its serotypes rapidly.

• 한국미생물·생명공학회지
• /
• 제23권2호
• /
• pp.214-219
• /
• 1995

In fermentation of dairy products, bifidobacteria is used in conjunction with other lactic acid bacteria, such as L. acidophilus, L. bulgaricus and S. thermophilus, rendering the enumeration of bifidobacteria difficult. In order to develop optimum conditions for selective enumeration of bifidobacteria, we examined MIC of several antibiotics against various bifidobacteria and other lactic acid bacteria. The growth of L. acidophilus, L. bulgaricus and S. thermophilus were inhibited by lithium chloride at the concentration of less than 4 mg/ml, whereas growth inhibition of bifidobacteria occurred at concentrations over 6-10 mg/ml. Tetracycline and chloramphenicol were also found to selectively inhibit growth of other lactic acid bacteria at the concentration of 1-3 $\mu$g/ml. Addition of 6 mg/ml lithium chloride, 1 $\mu$g/ml, tetracycline or 3 $\mu$g/ml chloramphenicol to medium was found to be optimal for selective enumeration of bifidobacteria. By using these three inhibitory chemicals in the TPY medium, higher number of bifidobacteria were selectively isolated than with NPNL agar and LP agar.

• 대한임상검사과학회지
• /
• 제46권4호
• /
• pp.140-142
• /
• 2014

To evaluate the recovery rates to increase toxigenic C. difficile, the selective enrichment broth culture methods were compared with commonly used cytotoxin assays and toxigenic culture. First, the enrichment culture, using the selective medium broth for 2 to 5 days, was performed and then, toxigenic C. difficile was confirmed by C. difficile toxin gene-specific PCR after being cultured on C. difficile selective agar. The sensitivity of C. difficile from the enrichment culture (100%) was higher than that of C. difficile selective agar culture (93.8%), while positive predictive values (PPV) were low; 72.7% (16/22) and 88.2% (15/17). PPV of the enrichment culture are not high. Recently, combinations of C. difficile selective agar culture, C. difficile A & B assays, glutamate dehydrogenase, and nucleic acid amplification method are widely used. The enrichment culture was disadvantageous in PPV, turn-around time, and cost. So, what we performed is not considered as a common method of diagnosis of C. difficile-associated diarrhea.

• 한국식품영양과학회지
• /
• 제40권7호
• /
• pp.1025-1031
• /
• 2011

본 연구는 식품으로부터 Shigella spp.를 검출하기 위해서 현재 사용되고 있는 분리배지를 대상으로 분리 성능을 비교하였다. MAC, SSA, DCA, XLD, HEA와 CHROMagar 총 6개의 분리배지를 대상으로 비교하였다. 일반 Shigella spp. 에 대한 성장은 MAC에서 TSA와 비슷한 수준 균수를 보였고 DCA에서 낮은 균수로 측정되었다. 소고기, 돼지고기, 새우를 대상으로 한 회수실험은 S. sonnei가 CHROMagar에서 성장이 유의적으로 높았으며(p<0.05) 양상추와 양배추에서는 S. sonnei가 SSA에서의 성장이 유의적으로 높게 나타났다(p<0.05). 식품 상재균은 소고기, 새우, 양배추에서 전체적으로 낮은 수준으로 측정되었으나 각 배지에서 유의적 차이는 없었다(p>0.05). 열 스트레스를 받은 S. sonnei는 MAC, SSA에서만 성장하였다. Enterobacteriaceae를 대상으로 한 선택성 측정 결과 HEA가 가장 높은 선택성을 나타내었다. Morganella spp.는 각 분리배지에서 Shigella spp.와 구분되지 못하였다. 실험에 사용된 배지는 각각의 조건에 따라 분리되는 특성이 상이하므로 식품에서 분리배지를 이용하여 Shigella spp.를 분리하고자 할 경우 분리 균의 상태에 따라 분리배지를 선택하여 사용하는 것이 바람직할 것으로 생각되었다.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제20권1호
• /
• pp.7-12
• /
• 2010

To determine the optimal isolation conditions of the entomopathogenic fungi from soil, we compared their growth characteristics with non-entomopathogenic fungi on agar media containing various concentrations of cooper (II) chloride ($CuCl_2$) or dodine. The result showed that dodine medium is more selective, and the optimal concentration of dodine is determined with $50{\mu}g$/ml. We could isolate several putative entomopathogenic fungi from soil using this, and identify them using ITS analysis. As a result, 64% fungi were identified as typical entomopathogenic fungi. This selective medium may be useful to the rapid and simple isolation of entomopathogenic fungi from soil.

• 한국동물위생학회지
• /
• 제28권2호
• /
• pp.113-119
• /
• 2005

We surveyed the distribution of Listeria spp in intestinal contents of slaughtered cattle from Daegu between March and October 2003. Fourteen Listeria spp were isolated from a total of 100 samples. Two samples contained only L innocua and other six samples contained both L monocytogenes and L innocua. Of the 99 samples positive to esculin reaction in Fraser broth, Listeria spp were isolated only from $8\%$ of the samples. Three selective plating medium were examined for detection of Listeria species including Enhanced hemolysis agar, Oxford agar and Palcam agar, It was found that Enhanced hemolysis agar was more effective than Oxford agar and Palcam agar, and that L monocytogenes needed 48 hour growth to give positive reaction.

• Journal of Microbiology
• /
• 제39권1호
• /
• pp.17-23
• /
• 2001

Various pretreatment procedures and selective media were applied to assess the optimal conditions for the isolation of rare actinomycetes from soil. Pretreatment of wet-heating for 15 min at 70$^{\circ}C$ and phenol treatment of soil suspension were the most effective methods for the isolation of these microorganisms. Hair hydrolysate vitamin agar (HHVA) was the most suitable medium for the recovery of rare actinomycetes. Thirty-five rare actinomycete strains were chosen using selective isolation approaches, then morphological and chemical properties of the isolates were determined. The isolates belonged to one of the following genus, Micromonospora, Microbispora, Actinoplanes and Streptosporangium.

• 한국식품과학회지
• /
• 제28권2호
• /
• pp.279-284
• /
• 1996

Leuconostocs는 김치를 비롯한 침채류의 발효에 중요한 세균이나 phenylethyl alcohol이나 vancomycin을 첨가하는 기존의 분리방법은 leuconostocs만을 순수분리할 수 없었을 뿐 아니라 가격이 비싼 것이 단점이었다. 여러가지 식품시료로부터 leuconostocs균주를 저렴하고도 효과적으로 분리할 수 있는 선택배지를 개발하기 위하여 모두 17균주의 leuconostocs와 lactobacilli에 대한 항생제 내성을 소사한 결과 leuconostocs의 novobiocin에 대한 MIC가 lactovacoilli에 비해 5배 이상 높은 것으로 나타났다. 이러한 결과를 기초로 하여 novobiocin이 첨가된 leuconotocs의 선택배지를 조제한 바 그 조성은 다음과 같다. 1% Tryptone (Dofco), 0.1% Yeast Extract (Difco), 2% sucrose, 0.1% Beef Extract (BBL), 0.5% sodium acetate, 0.2% ammonium sulfatc. 0.01% magnesium sulfate, 0.2% dipotassium phosphate, 0.05% sorbic acid, 75 ppm sodium azide (Sigma), 0.1% (vol/vol) Tween 80, 30 ${\mu}g/ml$ Vancomycin (Sigma), $5{\mu}g/ml$ Novobiocin (Sigma), $0.5{\mu}g/ml$ cysteine HCI, 1.5% Agar (Difco). 이 leuconostocs의 선택배지를 이용하여 여러가지 종류의 김치, 원유, cheese에서 총 86균주의 미생들을 분리하였다. 분석된 균들은 몇 가지 biochemical test를 통하여 동정한 결과 모두 Leuconostocs 속으로 확인되었으나 Leuconostoc mesenteroides subsp. cremoris와 Leuconostoc lactis는 검출할 수 없었다. 특히 이 배지는 분리 효율성이 MRS 배지에 비해 상대적으로 낮으므로 계수용 배지보다는 순수분리용 선택배비로의 이용이 적합하다 판단되었다.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
• /
• pp.92.2-93
• /
• 2003

Severe soybean-sprout rot was found at the mass productive factory in 2000 and 2001 and it caused 10-20％ loss of the production. Pythium sp. was isolated almost 90％ by potato dextrose agar from rotted root and hypocotylsof the sprouts. And the pathogencity tests using test tubes with 2％ water agar and small containers (30 ${\times}$ 30 ${\times}$ 50 cm, WxLxH) cultivation were shown a similar rot on roots and hypocotyls. The fungal mycelium grew rapidly on the water agar and it prevented the seed germination. Density of the Pythium sp. in the recycled water system at the factory was periodically measured using a selective medium, corn meal agar with Pimaricin 10 mg, Rifampicin 10 mg, Ampicillin 100 mg per 1 liter in order to check the contamination of recycled water. After fitering step using 5 and 1 ml in the recycled system was applied and it was effectively controlled Pythium rot. The daily yield of sprout was stable and the occurrenceof Pythium in the recycled water was much less after filtering. The fungal isolates were identified as Pythium deliense Meurs based on various mycological characteristics on corn meal agar and sucrose-asparagine bentgrass leaf culture medium. P. deliens oogonia were spherical, smooth, 19-23 urn in diameter, and their stalk bending toward antheridia. Antheridia were straw hat-shaped, curred club-shaped, therminal or intercalary, monoclinous, occasionally diclinous, 12∼15 ${\times}$ 8∼11 um, 1(∼2) per oogonium.

• 한국식물병리학회지
• /
• 제10권1호
• /
• pp.13-17
• /
• 1994

A semiselective agar medium (XCO) was developed for the isolation of bacterial blight pathogen, Xanthomonas campestris pv. oryzae, from rice seed. The medium contained yeast extract 1.0 g, peptone 2.0 g, sucrose 5.0 g, sodium glutamate 1.0 g, FeSO4.7H2O 0.05 g, Fe.EDTA 1 mg, cephalexin 20 mg, Evan blue (0.1%) 1.5 ml, bromcresol purple (0.1%) 2.5ml, cycloheximide 100 mg and agar 15.0 g per liter. Colonies of X. c. pv. oryzae were 4~5 mm in diameter, smooth, round, blue (darker center) and convex after 6 days incubation at 28$^{\circ}C$. The recovery of 6 isolates of X. c. pv. oryzae on the XOC medium ranged from 81% to 120% (mean 98.2%) in comparison to Wakimoto's medium. The number of saprophytic bacteria from 10 rice seed lots on XCO medium was reduced to 70.4% of that on Wakimoto's medium. The recovery of X. c. pv. oryzae added to rice seed on XOC medium ranged from 67% to 87% (mean 75.6%) of that on Wakimoto's medium.