• Journal of Microbiology and Biotechnology
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• 제31권12호
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• pp.1709-1715
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• 2021

Outbreaks of food poisoning due to the consumption of norovirus-contaminated shellfish continue to occur. Male-specific (F+) coliphage has been suggested as an indicator of viral species due to the association with animal and human wastes. Here, we compared two methods, the double agar overlay and the quantitative real-time PCR (RT-PCR)-based method, for evaluating the applicability of F+ coliphage-based detection technique in microbial contamination tracking of shellfish samples. The RT-PCR-based method showed 1.6-39 times higher coliphage PFU values from spiked shellfish samples, in relation to the double agar overlay method. These differences indicated that the RT-PCR-based technique can detect both intact viruses and non-particle-protected viral DNA/RNA, suggesting that the RT-PCR based method could be a more efficient tool for tracking microbial contamination in shellfish. However, the virome information on F+ coliphage-contaminated oyster samples revealed that the high specificity of the RT-PCR- based method has a limitation in microbial contamination tracking due to the genomic diversity of F+ coliphages. Further research on the development of appropriate primer sets for microbial contamination tracking is therefore necessary. This study provides preliminary insight that should be examined in the search for suitable microbial contamination tracking methods to control the sanitation of shellfish and related seawater.

• Parasites, Hosts and Diseases
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• 제53권5호
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• pp.641-645
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• 2015

Fascioliasis, a food-borne trematode zoonosis, is a disease primarily in cattle and sheep and occasionally in humans. Water dropwort (Oenanthe javanica), an aquatic perennial herb, is a common second intermediate host of Fasciola, and the fresh stems and leaves are widely used as a seasoning in the Korean diet. However, no information regarding Fasciola species contamination in water dropwort is available. Here, we collected 500 samples of water dropwort in 3 areas in Korea during February and March 2015, and the water dropwort contamination of Fasciola species was monitored by DNA sequencing analysis of the Fasciola hepatica and Fasciola gigantica specific mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS-2). Among the 500 samples assessed, the presence of F. hepatica cox1 and 1TS-2 markers were detected in 2 samples, and F. hepatica contamination was confirmed by sequencing analysis. The nucleotide sequences of cox1 PCR products from the 2 F. hepatica-contaminated samples were 96.5% identical to the F. hepatica cox1 sequences in GenBank, whereas F. gigantica cox1 sequences were 46.8% similar with the sequence detected from the cox1 positive samples. However, F. gigantica cox1 and ITS-2 markers were not detected by PCR in the 500 samples of water dropwort. Collectively, in this survey of the water dropwort contamination with Fasciola species, very low prevalence of F. hepatica contamination was detected in the samples.

• 한국산학기술학회논문지
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• 제11권12호
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• pp.4826-4832
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• 2010

본 연구는 2010년 6월 1일부터 2010년 7월 30일까지 2개월간 서울에 위치한 3곳의 약업사에서 각각 13종의 한약재를 구입하여 이들에 대한 총 호기성 세균 및 진균에 대한 미생물 오염 실태를 분석하여 한약재에 대한 미생물 오염 검사기준을 위한 기초자료로 활용하고자 수행되었다. WHO의 총 호기성 세균 및 진균수 오염한도인 $10^7$ CFU/g과 $10^4$ CFU/g과 비교하면, 총 호기성 균 오염(7.7%)보다는 진균의 오염(12.8%)이 더 높은 것으로 나타났다. 117개의 세균 집락을 대상으로 한 16S rRNA 유전자에 대한 DNA 상동성 분석은 내성 포자를 형성하는 B. cereus를 포함한 토양 유래 세균들이 약 96.6%를 차지하여 한약재의 채취와 보관 및 유통 과정에서의 미생물 오염 한도 기준 마련이 시급한 것으로 나타났다. 결론적으로 본 연구는 한약의 가공과정에 세균 및 진균의 혼입 가능성에 대한 시험조사와 함께 지속적인 한약재에 대한 미생물 오염실태 조사가 필요하다는 것을 시사하고 있다.

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.704-715
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• 2006

Oil spill was found in 1999 from a diesel storage facility located near the top of Baekun Mountain in Uiwang City. Application of bioremediation techniques was very relevant in removing oil spills in this site, because the geological condition was not amenable for other onsite remediation techniques. For efficient bioremediation, bacterial communities of the contaminated site and the uncontaminated control site were compared using both molecular and cultivation techniques. Soil bacterial populations were observed to be stimulated to grow in the soils contaminated with diesel hydrocarbon, whereas fungal and actinomycetes populations were decreased by diesel contamination. Most of the dieseldegrading bacteria isolated from contaminated forest soils were strains of Pseudomonas, Ralstonia, and Rhodococcus species. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that the profiles were different among the three contaminated sites, whereas those of the control sites were identical to each other. Analysis of 16S rDNA sequences of dominant isolates and clones showed that the bacterial community was less diverse in the oil-contaminated site than at the control site. Sequence analysis of the alkane hydroxylase genes cloned from soil microbial DNAs indicated that their diversity and distribution were different between the contaminated site and the control site. The results indicated that diesel contamination exerted a strong selection on the indigenous microbial community in the contaminated site, leading to predominance of well-adapted microorganisms in concurrence with decrease of microbial diversity.

• 분석과학
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• 제21권4호
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• pp.338-343
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• 2008

발굴된 유골에서 DNA 추출은 DNA신원확인과정에서 매우 중요한 단계이지만 유골에 오염된 미생물 DNA와 사람 DNA가 동시에 추출되는 문제점이 있다. 이를 극복하기 위해 발굴된 10명의 유골 시료를 페놀-ultrafiltration 후 $QIAquick^{(R)}$ PCR Purification Kit (ultrafiltration법)와 $QIAamp^{(R)}$ DNA Mini kit(Column-affinity법)를 적용하여 전체(미생물+사람) DNA정량 및 사람 DNA정량 후 각각 STR마커를 분석하므로서 DNA 분리 효율성을 확인하였다. 회수된 전체 DNA양은 Column-affinity법($19.6ng/{\mu}L$)이 ultrafiltration법($16.0ng/{\mu}L$) 보다 1.2배 더 나은 결과를 보였으나 사람 DNA 정량 결과로는 Column-affinity 법($0.034ng/{\mu}L$) 보다 ultrafiltration법($0.498ng/{\mu}L$)이 14.6배 더 많은 회수율을 나타냈다. 유골에 있던 다량의 미생물 DNA가 사람 DNA와 섞여있을 경우, 사람 DNA가 실리카 친화성 컬럼에 부착되는 것이 미생물 DNA의 영향을 받으나, 필터의 경우는 미생물 DNA의 영향을 받지 않아서 ultrafiltration법이 높은 회수율을 보였다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.245-245
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• 2017

Heavy metal pollution of agricultural soils affects land productivity and has impact on the quality of surrounding ecosystem. Soil microbial community parameters are used as reliable indices for assessing quality of agricultural lands under metal stress. This study investigated bacterial community structure of polluted and undisturbed paddy soils to elucidate soil factors that are related to alteration of bacterial communities under conditions of metal pollution. No obvious differences in the richness or diversity of bacterial communities were observed between samples from polluted and control areas. The bacterial communities of three locations were distinct from one another, and each location possessed distinctive set of bacterial phylotypes. The abundances of several phyla and genera differed significantly between study locations. Variation of bacterial community was mostly related to soil general properties at phylum level while at finer taxonomic levels concentrations of arsenic and lead were significant factors. According to results of bacterial community functional prediction, the soil bacterial communities of metal polluted locations were characterized by more abundant DNA replication and repair, translation, transcription and nucleotide metabolism pathway enzymes while amino acid and lipid metabolism as well as xenobiotic biodegradation potential was reduced.Our results suggest that the soil microbial communities had adapted to the elevated metal concentrations in the polluted soils as evidenced by changes in relative abundances of particular groups of microorganisms at different taxonomic resolution levels, and by altered functional potential of the microbial communities.

• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.806-811
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• 2007

Bacillus anthracis is a soil pathogen capable of causing anthrax that is closely related to several environmental species, including B. cereus, B. mycoides, and B. thuringiensis. DNA homology studies showed that B. anthracis, B. cereus, B. mycoides, and B. thuringiensis are closely related, with a high sequence homology. To establish a method to specifically detect B. anthracis in situations such as environmental contamination, we initially performed RAPD-PCR with a 10-mer random primer and confirmed the presence of specific PCR bands only in B. anthracis species. One region specific for B. anthracis was cloned and sequenced, and an internal primer set was designed to amplify a 241-bp DNA fragment within the sequenced region. The PCR system involving these specific primer sets has practical applications. Using lyses methods to prepare the samples for PCR, it was possible to quickly amplify the 241-bp DNA segment from samples containing only a few bacteria. Thus, the PCR detection method developed in this study is expected to facilitate the monitoring of environmental B. anthracis contamination.

• KSBB Journal
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• 제29권5호
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• pp.361-371
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• 2014

Mycoplasma is well recognized as one of the most prevalent and serious microbial contaminants of biologic manufacturing processes. Conventional methods for mycoplasma testing, direct culture method and indirect indicator cell culture method, are lengthy, costly and less sensitive to noncultivable species. In this report, we describe a new TaqMan probe-based real-time PCR method for rapid and quantitative detection of mycoplasma contamination during manufacture of biologics. Universal mycoplasma primers were used for mycoplasma PCR and mycoplasma DNA was quantified by use of a specific TaqMan probe. Specificity, sensitivity, and robustness of the real-time PCR method was validated according to the European Pharmacopoeia. The validation results met required criteria to justify its use as a replacement for the culture method. The established real-time PCR assay was successfully applied to the detection of mycoplasma from human keratinocyte and mesenchymal stem cell as well as Vero cell lines artificially infected with mycoplasma. The overall results indicated that this rapid, specific, sensitive, and robust assay can be reliably used for quantitative detection of mycoplasma contamination during manufacture of biologics.

• International Journal of Oral Biology
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• 제39권4호
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• pp.215-220
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• 2014

Toothbrushes play an essential role in oral hygiene. However, they can be significant in microbial transmission and can increase the risk of infection, since they can serve as a reservoir for microorganisms in healthy, oral-diseased and medically ill adults. This study was conducted to evaluate toothbrush contamination in six toothbrushes donated from four people. Two participants each supplied two toothbrushes - one used in the bathroom and one used in the workplace. The other two people each donated two toothbrushes used in the workplace. Polymerase chain reaction was used to construct a 16S rRNA clone library. Sequences of cloned DNA were compared with those from the reference organisms provided by GenBank. A total 120 clones, representing 20 clones for each toothbrush, were analyzed. They are composed of six pylum, 46 genera and 79 species. The most dominant species were Streptococcus oralis, Streptococcus parasanguinis and Haemophilus parainfluenzae. Enterobacter and Escherichia were recovered from toothbrushes used domestically. Toothbrushes used in the workplace did not contain Enterobacteria.

• 한국축산시설환경학회지
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• 제3권2호
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• pp.133-143
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• 1997

Optimal conditions for collecting, storing and drying temperature to utilize slaughter porcine blood for blood meals and the effects of blood meal on growth in broiler chicks were investigated. Dry matter and protein contents of slaughter procine blood were 19.5% and 77%(dry basis), respectively. As for the composites of amino acids in the blood, aspartic acid, arginine, glycine, histidine, leucine, lysine, phenylalanin threonine were shown high. There was no significant difference between the collections by bloodletting and vacuumming in terms of microbial contamination. Storage of slaughter porcine blood showed no differences in protein, DNA and triglyceride contents and pH between the storage methods of freezing (-20$^{\circ}C$) and refrigerating (-4$^{\circ}C$). In case of room temperature storage, however, the decrease in pH and the appearance of new protein due to microbial contaminations increased as the storage periods were prolonged. When drying was done by flash methods, the drying period got shortened as the temperature became higher, yet protein and triglyceride were destoryed more. When drying was done over 120$^{\circ}C$, even at the same degree, the breakdowns of protein and triglyceride increased more as drying period got longer. In feeding trials of broiler chicks, dietary supplementation of the flash dried blood meal at 2% level showed significant difference in growth rate(P＜.05%). These results indicated that the appropriate handling and manufacturing of slaughter porcine blood enabled the blood to be used as a protein source for broiler chicks.