• 제어로봇시스템학회논문지
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• 제12권5호
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• pp.419-424
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• 2006

In this study, a thermal control system which applied a Peltier device for the polymerase chain reaction(PCR) machine is to be designed. Here in order for it to easily follow the characteristics of the thermal cycle existing for gene amplification of the PCR sample, a PCR control board utilizing a thermal sensor, a Peltier, and a 8 bit microprocessor is made up. Especially a fuzzy type PD control algorithm is applied periodically in time response, and control system is implemented. For that matter, the characteristic data of subject system is obtained and analysed to begin with. Based on this analysed data, the proposed control algorithm is applied and an evaluation of the performance of the whole system take place through the PC.

• Tuberculosis and Respiratory Diseases
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• 제43권2호
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• pp.128-137
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• 1996

연구배경: 폐결핵은 고전적인 방법인 객담 도말 검사 및 배양검사로 전단할 수 있지만 객담 도말 민감도가 낮고 배양검사는 시일이 오래걸리는 단점이 있고 효과적인 객담배출이 되지 않는 환자에서는 검사가 불가능하기도 하다. 또한 최근에 개발된 PCR법은 신속하기는 하지만 위양성과 위음성이 문제가 되고 있다. 그래서 기관지내시경을 통한 기관지폐포세척액을 이용하여 세균학적 검사 및 PCR을 시행하여 폐결핵진단에 있어서 민감도와 예민도를 높이고 보다 신속한 진단을 할 수 있는지 연구하였다. 방법: 폐결핵 67예와 폐결핵이외의 폐질환을 가진 43예를 대상으로 객담 도말검사 및 배양검사를 시행하고, 기관지내시경을 시행하여 흉부 X-선상 병변이 보이는 엽상기관지에 기관지내시경을 위치하고 생리식염수 5cc로 3-5회에 걸쳐서 세척을 시행하여 세척액을 채취한 후 세균학적검사 및 PCR을 시행하였다. 결과: 1) 폐결핵환자의 기관지폐포세척액 결핵균 도말 검사 및 배양검사의 민감도는 각각 47.8% 및 80.6%로서, 객담 도말검사 및 배양검사의 민감도인 32.8% 및 57.4%보다 유의하게 높았다. 2) 폐결핵환자의 기관지폐포세척액 PCR의 민감도는 80.6%로서 배양검사의 민감도와 같았고, PCR의 배양검사에 대한 양성예측율은 81.5%였다. 3) 객담 도말검사 및 배양검사상 음성을 보인 폐결핵환자에서 시행한 기관지내시경을 통한 기관지폐포세척액 도말검사의 민감도는 23.1%였으며, 배양검사의 민감도는 100%였고, PCR의 민감도는 88.5%였으며, PCR의 배양검사에 대한 양성예측율 82.4%였다. 4) 기관지폐포세척액 PCR의 특이도는 77.0%였다. 5) 폐결핵의 최초 진단 후 치료시작까지의 기간은 객담 도말검사로 최초 진단이 된 경우가 평균 5일로 가장 빨랐고, 기관지폐포세척액 도말검사가 평균 9일, 기관지폐포세척액 PCR이 평균 26일이었으며, 객담배양검사는 평균 32일이었고, 기관지 폐포세척액 배양검사는 평균 56일로 가장 길었다. 결론: 폐결핵환자에서 기관지내시경을 통한 기관지폐포세척액의 결핵균 도말검사 및 배양검사는 객담을 이용한 검사보다 민감도가 높다. 그러므로, 객담을 배출하지 못하는 환자나 객담의 세균학적 검사가 음성인 환자에서 기관지내시경이 고려되어야 하며, 기관지폐포세척액의 PCR법까지 병행할 때에는 보다 신속하고 높은 진단율을 나타내므로, 조기에 적절한 항결핵제 투여에 도움이 될 것으로 기대된다.

• Environmental Engineering Research
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• 제14권1호
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• pp.63-67
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• 2009

Escherichia coli K-12 (E. coli K-12) is a representative indicator globally used for distinguishing and monitoring dynamic fates of pathogenic microorganisms in the environment. This study investigated how to most critically quantify lacZ ($\beta$-galactosidase) gene in E. coli K-12 by two different real-time polymerase chain reaction (real-time PCR) in association with three different DNA extraction practices. Three DNA extractions, i.e., sodium dodecyl sulfate (SDS)/proteinase K, magnetic beads and guanidium thiocyanate (GTC)/silica matrix were each compared for extracting total genomic DNA from E. coli K-12. Among them, GTC/silica matrix and magnetic beads beating similarly worked out to have the highest (22-23 ng/${\mu}L$) concentration of DNA extracted, but employing SDS/proteinase K had the lowest (10 ng/${\mu}L$) concentration of DNA retrieved. There were no significant differences in the quantification of the copy numbers of lacZ gene between SYBR Green I qPCR and QProbe-qPCR. However, SYBR Green I qPCR obtained somewhat higher copy number as $1{\times}10^8$ copies. It was decided that GTC/silica matrix extraction or magnetic beads beating in combination with SYBR Green I qPCR can be preferably applied for more effectively quantifying specific gene from a pure culture of microorganism.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.599-606
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• 2004

Gram-positive antagonistic bacilli were isolated from agricultural soils for possible use in biocontrol of plant pathogenic fungi, Fusarium oxysporum, Rhizoctonia solani, and/or Pythium ultimum. Among the 65 antagonistic Gram-positive soil isolates, 22 strains were identified as Bacillus species by 16S rDNA sequence analyses. Four strains, including DF14, especially exhibited multiple antagonistic properties against the three damping-off fungi. Genotypic properties of the Bacillus isolates were characterized by rapid molecular fingerprinting methods using repetitive extragenic palindromic-PCR (REP-PCR), ribosomal intergenic spacer-length polymorphisms (RIS-LP), 16S rDNA PCR-restriction fragment length polymorphisms (PCR-RFLP), and strain-specific PCR assays. The results indicated that the REP-PCR method was more valuable than the RIS-LP and 16S rDNA PCR-RFLP analyses as a rapid and reliable approach for bacilli typing and identification. The use of strain-specific primers designed based on 16S rDNA sequence comparisons enabled it to be possible to selectively detect a strain, DF14, which is being used as a biocontrol agent against damping-off fungi.

• The Plant Pathology Journal
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• 제19권3호
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• pp.159-161
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• 2003

The coat protein (CP) gene of Apple mosaic virus (ApMV), a member of the genus Ilarvirus, was selected for the design of virus-specific primers for amplification and molecular detection of the virus in cultivated apple. A combined assay of reverse transcription and polymerase chain reaction (RT-PCR) was performed with a single pair of ApMV-specific primers and crude nucleic acid extracts from virus-infected apple for rapid detection of the virus. The PCR product was verified by restriction mapping analysis and by sequence determination. The lowest concentration of template viral RNA required for detection was 100 fg. This indicates that the RT-PCR for detection of the virus is a 10$^3$times more sensitive, reproducible and time-saving method than the enzyme-linked immunosorbent assay. The specificity of the primers was verified using other unrelated viral RNAs. No PCR product was observed when Cucumber mosaic virus (Cucumovirus) or a crude extract of healthy apple was used as a template in RT-PCR with the same primers. The PCR product (669 bp) of the CP gene of the virus was cloned into the plasmid vector and result-ant recombinant (pAPCP1) was selected for molecule of apple transformation to breed virus-resistant transgenic apple plants as the next step. This method can be useful for early stage screening of in vitro plantlet and genetic resources of resistant cultivar of apple plants.

• 대한수의학회지
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• 제36권3호
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• pp.607-614
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• 1996

Several methods for rapid and accurate detection of VTe-producing E coli were established. These methods contain beta-glucuronidase-secretion test, beta-haemolysis-production test in blood agar, verocytotoxicity test, and PCR. All of the VTe-producing strains made beta-haemolysis on 5% sheep blood agar. VTe-producing strains secreted beta-glucuronidase whereas 0157:H7 strains producing VTI or VTII did not secrete that enzyme. Verocytotoxicity test was established for rapid diagnosis. VTe detection was rapider in Vero cell suspension than Vero cell monolayer. In PCR, there was a positive result only in VTe-producing E coli, not in VTI or VTII-producing E coli. In this experiment, 165 strains of E coli were islated from feces or intestinal contents of post-weaning piglets showing nervous sign or diarrhea. And 20 strains of E coli that produced VTe were selected by verocytotoxicity test and PCR. According to these experiments, there was a direct correlation between verocytotoxicity test and PCR. And verocytotoxicity test is recommended as a routine diagnostic method and PCR does as a accurate diagnostic method to detect VTe-producing E coli.

• 한국동물위생학회지
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• 제32권2호
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• pp.103-109
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• 2009

Influeza type A virus have been worldwide problematic in animals as well as in humans. In this study, the use of reverse-transcriptase polymerase chain reaction (RT-PCR) was described for detecting influenza virus type A. The primer of RT-PCR was designed from an nonstructural (NS) gene of Influenza A virus. By RT-PCR, a product with the size of 189 bp was detected only when influenza virus type A was used as template. No products could be detected with Influenza virus type B as well as other respiratory pathogens. The detection limit of the RT-PCR was up to $10^{0.3}TCID_{50}$ which is comparable to the sensitivity of cell culture method. The RT-PCR could detect the influenza A virus from nasal turbinates of the ferrets infected with influenza virus type A not type B.

• Parasites, Hosts and Diseases
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• 제49권3호
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• pp.281-284
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• 2011

Amebiasis is a protozoan disease caused by Entamoeba histolytica and a potential health threat in areas where sanitation and hygiene are inappropriate. Highly sensitive PCR methods for detection of E. histolytica in clinical and environmental samples are extremely useful to control amebiasis and to promote public health. The present study compared several primer sets for small subunit (SSU) rDNA and histone genes of E. histolytica cysts. A 246 bp of the SSU rDNA gene of pure cysts contained in phosphate-buffered saline (PBS) and in stool samples was successfully amplified by nested PCR, using the 1,147-246 bp primer set, of the primary PCR products which were pre-amplified using the 1,147 bp primer as the template. The detection limit of the nested PCR using the 1,147-246 primer set was 10 cysts in both groups (PBS and stool samples). The PCR to detect histone gene showed negative results. We propose that the nested PCR technique to detect SSU rDNA can be used as a highly sensitive genetic method to detect E. histolytica cysts in stool samples.

• Journal of Microbiology and Biotechnology
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• 제33권11호
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• pp.1457-1466
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• 2023

Enteric fever is caused by typhoidal Salmonella serovars (Typhi, Paratyphi A, Paratyphi B, and Paratyphi C). Owing to the importance of Salmonella serovars in clinics and public hygiene, reliable diagnostics for typhoidal serovars are crucial. This study aimed to develop a novel diagnostic tool for typhoidal Salmonella serovars and evaluate the use of human blood for clinically diagnosing enteric fever. Five genes were selected to produce specific PCR results against typhoidal Salmonella serovars based on the genes of Salmonella Typhi. Heptaplex PCR, including genetic markers of generic Salmonella, Salmonella enterica subsp. enterica, and typhoidal Salmonella serovars, was developed. Typhoidal Salmonella heptaplex PCR using genomic DNAs from 200 Salmonella strains (112 serovars) provided specifically amplified PCR products for each typhoidal Salmonella serovar. These results suggest that heptaplex PCR can sufficiently discriminate between typhoidal and non-typhoidal Salmonella serovars. Heptaplex PCR was applied to Salmonella-spiked blood cultures directly and provided diagnostic results after 12- or 13.5-h blood culture. Additionally, it demonstrated diagnostic performance with colonies recovered from a 6-h blood culture. This study provides a reliable DNA-based tool for diagnosing typhoidal Salmonella serovars that may be useful in clinical microbiology and epidemiology.

• 식물병연구
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• 제9권3호
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• pp.116-120
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• 2003

참다래 잎으로부터 궤양병균인 Pseudomnoas syringae pv. actinidiae를 배양하여 PCR을 통해 검출하는 방법을 개발하였다. Nested PCR을 위해 두 set의 primer를 식물 독소인 coronatine의 생합성에 관여하는 유전자 cfl의 염기서열로부터 설계하였다. 이 primer set를 사용하여 665rhk 310-bp의 절편이 증폭되었으며 nested PCR을 통한 궤양병균의 검출한계는 20 CFU/ml이었다. 4 그루의 참다래 나무로부터 노란색 무리로 나타나는 궤양병 초기 증상을 보이는 잎을 채취하여 pepton-sucrose 액체배지에 넣어 $16^{\circ}$C에서 12시간 배양 한뒤 PCR 을 시행한 결과 한 시료에서 예상했던 밴드가 증폭되었고 이듬해 봄 이 나무가 궤양병에 감염되었음을 확인하였다.