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1.
Aim:  To evaluate commercial DNA extraction kits for their ability to isolate DNA from Yersinia pestis suspensions and spiked environmental samples.
Methods and Results:  Five commercially available DNA extraction kits were evaluated: the ChargeSwitch gDNA Mini Bacteria Kit, the IT 1-2-3 Sample DNA Purification Kit, the MasterPure Complete DNA and RNA Purification Kit, the QIAamp DNA Blood Mini Kit and the UltraClean Microbial DNA Isolation Kit. The extraction methods were performed upon six Y. pestis strains and spiked environmental specimens, including three swab types and one powder type. Taqman real-time PCR analysis revealed that the use of the MasterPure kit resulted in DNA with the most consistently positive results and the lowest limit of detection from Y. pestis suspensions and spiked environmental samples.
Conclusion:  Comparative evaluations of the five commercial DNA extraction methods indicated that the MasterPure kit was superior for the isolation of PCR-amplifiable DNA from Y. pestis suspensions and spiked environmental samples.
Significance and Impact of the Study:  The results of this study can assist diagnostic laboratories with selecting the best extraction method for processing environmental specimens for subsequent detection of Y. pestis by real-time PCR.  相似文献   

2.
Burkholderia pseudomallei, the etiologic agent of melioidosis, is endemic in northern Australia and Southeast Asia and can cause severe septicemia that may lead to death in 20% to 50% of cases. Rapid detection of B. pseudomallei infection is crucial for timely treatment of septic patients. This study evaluated seven commercially available DNA extraction kits to determine the relative recovery of B. pseudomallei DNA from spiked EDTA-containing human whole blood. The evaluation included three manual kits: the QIAamp DNA Mini kit, the QIAamp DNA Blood Mini kit, and the High Pure PCR Template Preparation kit; and four automated systems: the MagNAPure LC using the DNA Isolation Kit I, the MagNAPure Compact using the Nucleic Acid Isolation Kit I, and the QIAcube using the QIAamp DNA Mini kit and the QIAamp DNA Blood Mini kit. Detection of B. pseudomallei DNA extracted by each kit was performed using the B. pseudomallei specific type III secretion real-time PCR (TTS1) assay. Crossing threshold (CT) values were used to compare the limit of detection and reproducibility of each kit. This study also compared the DNA concentrations and DNA purity yielded for each kit. The following kits consistently yielded DNA that produced a detectable signal from blood spiked with 5.5×104 colony forming units per mL: the High Pure PCR Template Preparation, QIAamp DNA Mini, MagNA Pure Compact, and the QIAcube running the QIAamp DNA Mini and QIAamp DNA Blood Mini kits. The High Pure PCR Template Preparation kit yielded the lowest limit of detection with spiked blood, but when this kit was used with blood from patients with confirmed cases of melioidosis, the bacteria was not reliably detected indicating blood may not be an optimal specimen.  相似文献   

3.
The aim of this study was to compare the efficiency of DNA extraction from water as well as from blood samples spiked with A. fumigatus spores, using selected commercial kits. Extraction of DNA according to manufacturer's protocols was preceded by blood cells lysis and disruption of fungal cells by enzymatic digestion or bead beating. The efficiency of DNA extraction was measured by PCR using Aspergillus-specific primers and SYBR Green I dye or TaqMan probes targeting 28S rRNA gene. All methods allowed the detection of Aspergillus at the lowest tested density of water suspensions of spores (101 cells/ml). The highest DNA yield was obtained using the ZR Fungal/Bacterial DNA kit, YeastStar Genomic DNA kit, and QIAamp DNA Mini kit with mechanical cell disruption. The ZR Fungal/Bacterial DNA and YeastStar kits showed the highest sensitivity in examination of blood samples spiked with Aspergillus (100 % for the detection of 102 spores and 75 % for 101 spores). Recently, the enzymatic method ceased to be recommended for examination of blood samples for Aspergillus, thus ZR Fungal/Bacterial DNA kit and QIAamp DNA Mini kit with mechanical cell disruption could be used for extraction of Aspergillus DNA from clinical samples.  相似文献   

4.
Eight DNA extraction products or methods (Applied Biosystems PrepFiler Forensic DNA Extraction Kit; Bio-Rad Instagene Only, Bio-Rad Instagene & Spin Column Purification; EpiCentre MasterPure DNA & RNA Kit; FujiFilm QuickGene Mini80; Idaho Technologies 1-2-3 Q-Flow Kit; MoBio UltraClean Microbial DNA Isolation Kit; Sigma Extract-N-Amp Plant and Seed Kit) were adapted to facilitate extraction of DNA under BSL3 containment conditions. DNA was extracted from 12 common interferents or sample types, spiked with spores of Bacillus atropheaus. Resulting extracts were tested by real-time PCR. No one method was the best, in terms of DNA extraction, across all sample types. Statistical analysis indicated that the PrepFiler method was the best method from six dry powders (baking, biological washing, milk, plain flour, filler and talcum) and one solid (Underarm deodorant), the UltraClean method was the best from four liquids (aftershave, cola, nutrient broth, vinegar), and the MasterPure method was the best from the swab sample type. The best overall method, in terms of DNA extraction, across all sample types evaluated was the UltraClean method.  相似文献   

5.
High-quality nucleic acids are critical for optimal PCR-based diagnostics and pathogen detection. Rapid sample processing time is important for the earliest administration of therapeutic and containment measures, especially in the case of biothreat agents. In this context, we compared the Fujifilm QuickGene-Mini80 to Qiagen's QIAamp Mini Purification kits for extraction of DNA and RNA for potential use in austere settings. Qiagen (QIAamp) column-based extraction is the currently recommended purification platform by United States Army Medical Research Institute for Infectious Diseases for both DNA and RNA extraction. However, this sample processing system requires dedicated laboratory equipment including a centrifuge. In this study, we investigated the QuickGene-Mini80, which does not require centrifugation, as a suitable platform for nucleic acid extraction for use in resource-limited locations. Quality of the sample extraction was evaluated using pathogen-specific, real-time PCR assays for nucleic acids extracted from viable and γ-irradiated Bacillus anthracis, Yersinia pestis, vaccinia virus, Venezuelan equine encephalitis virus, or B. anthracis spores in buffer or human whole blood. QuickGene-Mini80 and QIAamp performed similarly for DNA extraction regardless of organism viability. It was noteworthy that γ-irradiation did not have a significant impact on real-time PCR for organism detection. Comparison with QIAamp showed a less than adequate performance of the Fujifilm instrument for RNA extraction. However, QuickGene-Mini80 remains a viable alternative to QIAamp for DNA extraction for use in remote settings due to extraction quality, time efficiency, reduced instrument requirements, and ease of use.  相似文献   

6.
The human gut harbors a vast range of microbes that have significant impact on health and disease. Therefore, gut microbiome profiling holds promise for use in early diagnosis and precision medicine development. Accurate profiling of the highly complex gut microbiome requires DNA extraction methods that provide sufficient coverage of the original community as well as adequate quality and quantity. We tested nine different DNA extraction methods using three commercial kits (TianLong Stool DNA/RNA Extraction Kit (TS), QIAamp DNA Stool Mini Kit (QS), and QIAamp PowerFecal DNA Kit (QP)) with or without additional bead-beating step using manual or automated methods and compared them in terms of DNA extraction ability from human fecal sample. All methods produced DNA in sufficient concentration and quality for use in sequencing, and the samples were clustered according to the DNA extraction method. Inclusion of bead-beating step especially resulted in higher degrees of microbial diversity and had the greatest effect on gut microbiome composition. Among the samples subjected to bead-beating method, TS kit samples were more similar to QP kit samples than QS kit samples. Our results emphasize the importance of mechanical disruption step for a more comprehensive profiling of the human gut microbiome.  相似文献   

7.
The purity of DNA extracted from faecal samples is a key issue in the sensitivity and usefulness of biological analyses such as PCR for infectious pathogens and non-pathogens. We have compared the relative efficacy of extraction of bacterial DNA (both Gram negative and positive origin) from faeces using four commercial kits (FastDNA kit, Bio 101; Nucleospin C+T kit, Macherey-Nagal; Quantum Prep Aquapure Genomic DNA isolation kit, Bio-Rad; QIAamp DNA stool mini kit, Qiagen) and a non-commercial guanidium isothiocyanate/silica matrix method. Human faecal samples were spiked with additional known concentrations of Lactobacillus acidophilus or Bacteroides uniformis, the DNA was then extracted by each of the five methods, and tested in genus-specific PCRs. The Nucleospin method was the most sensitive procedure for the extraction of DNA from a pure bacterial culture of Gram-positive L. acidophilus (10(4) bacteria/PCR), and QIAamp and the guanidium method were most sensitive for cultures of Gram-negative B. uniformis (10(3) bacteria/PCR). However, for faecal samples, the QIAamp kit was the most effective extraction method and led to the detection of bacterial DNA over the greatest range of spike concentrations for both B. uniformis and L. acidophilus in primary PCR reactions. A difference in extraction efficacy was observed between faecal samples from different individuals. The use of appropriate DNA extraction kits or methods is critical for successful and valid PCR studies on clinical, experimental or environmental samples and we recommend that DNA extraction techniques are carefully selected with particular regard to the specimen type.  相似文献   

8.
Molecular characterization of the microbial populations of soils and sediments contaminated with polycyclic aromatic hydrocarbons (PAHs) is often a first step in assessing intrinsic biodegradation potential. However, soils are problematic for molecular analysis owing to the presence of organic matter, such as humic acids. Furthermore, the presence of contaminants, such as PAHs, can cause further challenges to DNA extraction, quantification, and amplification. The goal of our study was to compare the effectiveness of four commercial soil DNA extraction kits (UltraClean Soil DNA Isolation kit, PowerSoil DNA Isolation kit, PowerMax Soil DNA Isolation kit, and FastDNA SPIN kit) to extract pure, high-quality bacterial and eukaryotic DNA from PAH-contaminated soils. Six different contaminated soils were used to determine if there were any biases among the kits due to soil properties or level of contamination. Extracted DNA was used as a template for bacterial 16S rDNA and eukaryotic 18S rDNA amplifications, and PCR products were subsequently analyzed using denaturing gel gradient electrophoresis (DGGE). We found that the FastDNA SPIN kit provided significantly higher DNA yields for all soils; however, it also resulted in the highest levels of humic acid contamination. Soil texture and organic carbon content of the soil did not affect the DNA yield of any kit. Moreover, a liquid-liquid extraction of the DNA extracts found no residual PAHs, indicating that all kits were effective at removing contaminants in the extraction process. Although the PowerSoil DNA Isolation kit gave relatively low DNA yields, it provided the highest quality DNA based on successful amplification of both bacterial and eukaryotic DNA for all six soils. DGGE fingerprints among the kits were dramatically different for both bacterial and eukaryotic DNA. The PowerSoil DNA Isolation kit revealed multiple bands for each soil and provided the most consistent DGGE profiles among replicates for both bacterial and eukaryotic DNA.  相似文献   

9.
摘要:目的 优化新生儿粪便样本DNA提取方法,提取及分析体重差异双胎新生儿粪便样本DNA。方法 从7种DNA提取试剂盒方法中选择对成人粪便样本DNA提取效果最佳的QIAamp DNA Stool Mini Kit法为基准方法,通过钢珠打断前处理、DNA吸附柱收集全部裂解液上清和洗脱液重复洗脱的优化,建立了用于新生儿粪便样本DNA的提取方法。结果 该优化方法用于婴儿(出生1个月)粪便样本,结果显示DNA提取浓度平均提高了2.4倍。用于48对双胞胎新生儿出生第1天和第3天粪便样本DNA的提取,经酶标仪及PCR扩增检测,结果显示出生第1天粪便样本DNA提取率为32%,出生3天提取率达83%。RT-PCR显示新生儿第1天到第3天肠道微生物量呈现增长趋势。结论 优化的QIAamp DNA Stool Mini Kit法适用于新生儿粪便样本DNA的快速提取,为后续扩增子高通量测序和研究体重差异双胎新生儿肠道菌群构成规律奠定基础。  相似文献   

10.
This study establishes a filtration method for the safe removal of Bacillus anthracis spores which may contaminate DNA preparations. Centrifugal filtration with 0.1-microm filter units can be used following extraction of DNA from B. anthracis spores to render samples safe without compromising the sensitivity of diagnostic real-time PCR assays for B. anthracis.  相似文献   

11.
Three DNA extraction kits were used, all without preliminary procedures, then DNA extraction was preceded with freeze/thaw cycles in three versions. A lack of desired effect resulted in the application of liquid nitrogen/water bath cycles before the use of the extractions in further experiments. The effectiveness of DNA extraction was measured by PCR signal and C(T) values of real time PCR. A comparison of the efficiency of various Cryptosporidium parvum undiluted oocyst treatments prior to DNA extraction with the use of three kits has shown that the best results were obtained after extraction of DNA with the QIAamp DNA Tissue Mini Kit (T kit), preceded by triple liquid nitrogen/water bath in 100 degrees C for 2 minutes and with overnight proteinase K digestion. After extraction with the T kit, the detection limit was 50 oocysts per 200 microl when effectiveness was evaluated with PCR and 10 oocysts in the case of real time PCR.  相似文献   

12.
Difficulty in disrupting cysts of Giardia intestinalis, a cosmopolitan protozoan parasite, decreases the yield of DNA extracted and reduces the effectiveness of the polymerase chain reaction (PCR). To improve the detection of the Giardia Glutamate Dehydrogenase (gdh) gene, we re-evaluated the effects of deoxyribonucleic acid (DNA) extraction methods. Purified and concentrated cysts from 33 fecal samples were disrupted using conventional methods, and DNA extraction was conducted using two protocols: the QIAamp Stool Mini Kit and phenol/chloroform/isoamyl alcohol (PCI). PCR amplification was successful for 12 extracted DNA samples (36%) using PCI following a glass bead and freeze/thaw pretreatment and for all 33 samples (100%) using the QIAamp Stool Mini Kit following the aforementioned pretreatment. Consequently, the pretreatment of cysts with glass beads and freeze/thaw cycles followed by extraction of DNA with the QIAamp Stool Mini kit was the more effective protocol.  相似文献   

13.
Real-time PCR for the detection of Cryptosporidium parvum.   总被引:9,自引:0,他引:9  
Real time, TaqMan PCR assays were developed for the Cp11 and 18S rRNA genes of the protozoan parasite Cryptosporidium parvum. The TaqMan probes were specific for the genus Cryptosporidium, but could not hybridize exclusively with human-infectious C. parvum species and genotypes. In conjunction with development of the TaqMan assays, two commercial kits, the Mo Bio UltraClean Soil DNA kit, and the Qiagen QIAamp DNA Stool kit, were evaluated for DNA extraction from calf diarrhea and manure, and potassium dichromate and formalin preserved human feces. Real-time quantitation was achieved with the diarrhea samples, but nested PCR was necessary to detect C. parvum DNA in manure and human feces. Ileal tissues were obtained from calves at 3, 7, and 14 days post-infection, and DNA extracted and assayed. Nested PCR detected C. parvum DNA in the 7-day post-infection sample, but neither of the other time point samples were positive. These results indicate that real-time quantitation of C. parvum DNA, extracted using the commercial kits, is feasible on diarrheic feces, with large numbers of oocysts and small concentrations of PCR inhibitor(s). For samples with few oocysts and high concentrations of PCR inhibitor(s), such as manure, nested PCR is necessary for detection.  相似文献   

14.

Aims

Nine commercial DNA extraction kits were evaluated for the isolation of DNA from 10‐fold serial dilutions of Bacillus anthracis spores using quantitative real‐time PCR (qPCR). The three kits determined by qPCR to yield the most sensitive and consistent detection (Epicenter MasterPure Gram Positive; MoBio PowerFood; ABI PrepSeq) were subsequently tested for their ability to isolate DNA from trace amounts of B. anthracis spores (approx. 6·5 × 101 and 1·3 × 102 CFU in 25 ml or 50 g of food sample) spiked into complex food samples including apple juice, ham, whole milk and bagged salad and recovered with immunomagnetic separation (IMS).

Methods and Results

The MasterPure kit effectively and consistently isolated DNA from low amounts of B. anthracis spores captured from food samples. Detection was achieved from apple juice, ham, whole milk and bagged salad from as few as 65 ± 14, 68 ± 8, 66 ± 4 and 52 ± 16 CFU, respectively, and IMS samples were demonstrated to be free of PCR inhibitors.

Conclusions

Detection of B. anthracis spores isolated from food by IMS differs substantially between commercial DNA extraction kits; however, sensitive results can be obtained with the MasterPure Gram Positive kit.

Significance and Impact of the Study

The extraction protocol identified herein combined with IMS is novel for B. anthracis and allows detection of low levels of B. anthracis spores from contaminated food samples.  相似文献   

15.
Cell lysis efficiency and the quality of DNA extracts from complex bacterial ecosystems are two major concerns in molecular ecological studies of gut microbiota. In this study, we use PCR-denaturing gradient gel electrophoresis (DGGE) DNA profiling, random cloning and sequence analysis of 16S rRNA genes to compare the QIAamp DNA Stool Mini Kit with the bead beating technique in the preparation of DNA extracts from gut microbiota of pigs. We also developed a washing procedure that can release more than 93% of bacterial cells attached to the gut mucosa. Both the QIAamp kit and bead beating method lysed approximately 95% of bacterial cells. PCR-DGGE DNA profiles of ileal and cecal microbiota from both digesta and mucosa that were generated from the DNA extracts using the two methods were nearly identical. Random cloning and sequence analysis also demonstrated the high quality of DNA extracts using the two methods. Two random clone sets of 16S rRNA genes generated from the DNA extracts had a similar degree of bacterial diversity. Different preparations of DNA extract from a single sample using the QIAamp kit consistently produced similar PCR-DGGE DNA profiles with similarity indexes higher than 99%. Our data suggest the appropriateness of the QIAamp DNA Stool Mini Kit for the studies of gut microbial ecology and the effectiveness of the QIAamp kit in processing multiple samples for cell lysis and DNA extraction.  相似文献   

16.
The aim of this study was to develop a PCR-based rapid method to detect Bacillus cereus group cells from paper and cardboard. Primers targeting the 16S rDNA and real-time PCR with SYBR green I detection were used in order to be able to also quantify the target. Both autoclaved cardboard samples spiked with B. cereus vegetative cells or spores and naturally contaminated paper and cardboard samples were studied. Results were compared with culturing verified by commercial (API) tests. Several different methods were tested for DNA isolation from the paper and cardboard samples. Two commercial kits intended for soils, the UltraClean soil DNA kit and the FastDNA spin kit for soil, gave the most reproducible results. In spiked samples, the average yield was 50% of added vegetative cells, but spore yield was only about 10%. PCR results from adding vegetative cells correlated with added colony-forming unit (cfu) values (r=0.93, P <0.001) in the range 100–10,000 cfu g–1. Three out of nine studied paper and cardboard samples contained B. cereus group bacteria, based both on culturing and real-time PCR. The numbers were 102–103 bacteria g–1; and PCR gave somewhat higher results than culturing. Thus, real-time PCR can be used as a rapid semi-quantitative method to screen paper and cardboard samples for contamination with B. cereus group bacteria.  相似文献   

17.
Aims: To evaluate six commercial DNA extraction kits for their ability to isolate PCR‐quality DNA from Bacillus spores in various soil samples. Methods and Results: Three soils were inoculated with various amounts of Bacillus cereus spores to simulate an outbreak or intentional release of the threat agent Bacillus anthracis. DNA was isolated from soil samples using six commercial DNA extraction kits. Extraction and purification efficiencies were assessed using a duplex real‐time PCR assay that included an internal positive control. The FastDNA® SPIN kit for Soil showed the highest DNA extraction yield, while the E.Z.N.A.® Soil DNA and PowerSoil® DNA Isolation kits showed the highest efficiencies in removing PCR inhibitors from loam soil extracts. Conclusions: The results of this study suggest that commercially available extraction kits can be used to extract PCR‐quality DNA from bacterial spores in soil. The selection of an appropriate extraction kit should depend on the characteristics of the soil sample and the intended downstream application. Significance and Impact of the Study: The results of this study aid in the selection of an appropriate DNA extraction kit for a given soil sample. Its application could expedite sample processing for real‐time PCR detection of a pathogen in soil.  相似文献   

18.
Loop-mediated isothermal amplification (LAMP) is a technique capable of rapidly amplifying specific nucleic acid sequences without specialized thermal cycling equipment. In addition, several detection methods that include dye fluorescence, gel electrophoresis, turbidity and colorimetric change, can be used to measure or otherwise detect target amplification. To date, publications have described the requirement for some form of sample nucleic acid extraction (boiling, lysis, DNA purification, etc.) prior to initiating a LAMP reaction. We demonstrate here, the first LAMP positive results obtained from vegetative cells and spores of Bacillus anthracis without nucleic acid extraction. Our data show that the simple addition of cells or spores to the reaction mixture, followed by heating at 63°C is all that is required to reproducibly amplify and detect target plasmid and chromosomal DNA via colorimetric change. The use of three primer sets targeting both plasmids and the chromosome of B. anthracis allows for the rapid discrimination of non-pathogenic bacteria from pathogenic bacteria within 30 min of sampling. Our results indicate that direct testing of B. anthracis spores and cells via LAMP assay will greatly simplify and shorten the detection process by eliminating nucleic acid purification. These results may allow more rapid detection of DNA from pathogenic organisms present in field and environmental samples.  相似文献   

19.
On-line cell lysis of bacteria and its spores using a microfluidic biochip   总被引:1,自引:0,他引:1  
Optimal detection of pathogens by molecular methods in water samples depends on the ability to extract DNA rapidly and efficiently. In this study, an innovative method was developed using a microfluidic biochip, produced by microelectrochemical system technology, and capable of performing online cell lysis and DNA extraction during a continuous flow process. On-chip cell lysis based on chemical/physical methods was performed by employing a sufficient blend of water with the lysing buffer. The efficiency of lysis with microfluidic biochip was compared with thermal lysis in Eppendorf tubes and with two commercial DNA extraction kits: Power Water DNA isolation kit and ForensicGEM Saliva isolation kit in parallel tests. Two lysing buffers containing 1% Triton X-100 or 5% Chelex were assessed for their lysis effectiveness on a microfluidic biochip. SYBR Green real-time PCR analysis revealed that cell lysis on a microfluidic biochip using 5% Chelex buffer provided better or comparable recovery of DNA than commercial isolation kits. The system yielded better results for Gram-positive bacteria than for Gram-negative bacteria and spores of Gram-positive bacteria, within the limits of detection at 103 CFU/ml. During the continuous flow process in the system, rapid cells lysis with PCR-amplifiable genomic DNA were achieved within 20 minutes.  相似文献   

20.
Aim Comparison of manual and automatic (MagNA Pure) isolation methods of total RNA from adipose tissue with respect to its quality and recovery factor. Material 120 human subcutaneous adipose tissue samples (about 100 mg/sample) were collected from patients during surgical operations. The tissue sample was stabilized in RNAlater (QIAGEN GmbH, Germany). Methods Total RNA was extracted by the following kits: Rneasy Protect Mini, Rneasy Lipid Tissue (QIAGEN GmbH, Germany) and MagNA Pure Compact RNA Isolation (Tissue) for MagNA Pure Compact Instrument (Roche Diagnostics GmbH, Germany). Results The average RNA yields with Rneasy Lipid Tissue kits were about two-fold higher in comparison with the Rneasy Protect Mini kit. When the MagNA Pure Compact System was used, RNA yields from the same sample were more uniform compared with manual systems. It was also more convenient and less time-consuming than the manual approach. No DNA contamination of total RNA samples was detected except for samples isolated by Rneasy Protect Mini Kit. Conclusion Rneasy Lipid Tissue Kit and MagNA Pure Compact RNA Isolation Kit (Tissue) provide RNA samples of high quantity, purity and PCR amplificability. RNA samples are suitable for further processing using methods of molecular biology.  相似文献   

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