WO2021114501A1 - 基于纳米孔测序的泌尿宏基因组样本建库和检测方法 - Google Patents

基于纳米孔测序的泌尿宏基因组样本建库和检测方法 Download PDF

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WO2021114501A1
WO2021114501A1 PCT/CN2020/079091 CN2020079091W WO2021114501A1 WO 2021114501 A1 WO2021114501 A1 WO 2021114501A1 CN 2020079091 W CN2020079091 W CN 2020079091W WO 2021114501 A1 WO2021114501 A1 WO 2021114501A1
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host
sample
final concentration
minutes
sequencing
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杨帆
吴苏生
郭晓东
赵成娜
胡龙
李杜衡
涂浩波
任用
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北京先声医学检验实验室有限公司
江苏先声医学诊断有限公司
南京先声医学检验有限公司
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Priority claimed from CN201911297880.2A external-priority patent/CN111304285B/zh
Priority claimed from CN201911341615.XA external-priority patent/CN111304286B/zh
Application filed by 北京先声医学检验实验室有限公司, 江苏先声医学诊断有限公司, 南京先声医学检验有限公司 filed Critical 北京先声医学检验实验室有限公司
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    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K38/00Medicinal preparations containing peptides
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    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12QMEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
    • C12Q1/00Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
    • C12Q1/68Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving nucleic acids
    • CCHEMISTRY; METALLURGY
    • C40COMBINATORIAL TECHNOLOGY
    • C40BCOMBINATORIAL CHEMISTRY; LIBRARIES, e.g. CHEMICAL LIBRARIES
    • C40B50/00Methods of creating libraries, e.g. combinatorial synthesis

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  • the present invention relates to the field of biotechnology, in particular to a method for building and detecting a urinary metagenomic sample based on a nanopore sequencing platform.
  • Metagenomic sequencing overcomes the identification shortcomings of many pathogens that cannot be cultured, and is increasingly used in the identification of clinical samples of urinary system infections, especially the identification of pathogens of unknown causes and mixed bacterial infections.
  • the current mainstream high-throughput sequencing method is mainly based on the NGS second-generation sequencing method, which usually takes a long time from sample to result (>72h); the length of sequencing reads increases the difficulty and duration of generation letter assembly, and is short at the same time.
  • the first object of the present invention is to provide a method for dehosting urinary metagenomic samples based on a nanopore sequencing platform
  • the second objective of the present invention is to provide a method for constructing a library of urinary metagenomic samples based on a nanopore sequencing platform.
  • the third object of the present invention is to provide a urinary metagenomic sample sequencing and identification method based on a nanopore sequencing platform.
  • a method for removing the host of a urine sample metagenomics characterized in that the method of removing the host comprises:
  • the host DNA free step includes: using Saponin free host DNA at a final concentration of 0.1-0.5% (w/v) for 5-15 minutes; the host DNA degradation step includes: using a final concentration of 0.3-1% (v/v) v) HL-SAN degrades host DNA for 10-20 minutes.
  • the host DNA free step includes: using Saponin free host DNA with a final concentration of 0.22% (w/v) for 10 minutes; the host DNA degradation step includes: using a final concentration of 0.49% (v/v) of HL- SAN degrades host DNA for 15 minutes.
  • the step of centrifuging the sample includes: taking a urinary sample at 12,300 g and centrifuging and resuspending and mixing in PBS;
  • the bacteria collection step includes: resuspending in PBS and then centrifuging at 10000 g for 3 minutes, discarding the supernatant to obtain a host sample;
  • the sample centrifugation step includes: taking a urinary sample, centrifuging at 12300g for 5 min; discarding the supernatant, resuspending the pellet in 250ul PBS, and mixing;
  • the host DNA dissociation step includes: adding a final concentration of 0.22% (w/ v) Saponin, room temperature for 10 minutes; add 350ul sterile water to mix, 30 seconds later, add 12ul 5M NaCl to mix;
  • the host DNA degradation step includes: 10000g centrifugation for 5 minutes, resuspend in PBS, add a final concentration of 0.49% (v/v ) HL-SAN, and incubate at 37° C., 1300 rpm for 15 min;
  • the bacteria collection step includes: resuspending in 800ul PBS, centrifuging at 10000g for 3 min, discarding the supernatant to obtain a host sample.
  • a method for sequencing and identification of metagenomics of urine samples characterized in that the method comprises:
  • the dehosting step includes the above-mentioned steps.
  • the PCR amplification reaction system for library construction contains 3-5% (v/v) dimethyl sulfoxide
  • the content of the dimethyl sulfoxide is 4% (v/v).
  • the pre-denaturation temperature in the PCR amplification library building reaction program is 96.5-97.5°C
  • the pre-denaturation time is 2-4min
  • the denaturation temperature is 96.5-97.5°C
  • the denaturation time is 15-25s
  • the extension time is 5. -7min;
  • reaction procedure of the PCR amplification is:
  • a dehost kit for urinary metagenomic samples based on a nanopore sequencing platform characterized in that the kit contains Saponin with a final concentration of 0.22% (w/v) and a final concentration of 0.49% (v/v) HL-SAN.
  • a method for building a library of urinary metagenomic samples based on a nanopore sequencing platform The samples to be tested are sequentially removed from the host and the genome is extracted, and then labeled, and the obtained labeled template is amplified by PCR to build the library;
  • the PCR amplification reaction system contains 3-5% (v/v) dimethyl sulfoxide
  • the PCR amplification reaction program promotes the unwinding and extension of templates with high GC content.
  • the content of the dimethyl sulfoxide is 4% (v/v).
  • the pre-denaturation temperature is 96.5-97.5°C
  • the pre-denaturation time is 2-4min
  • the denaturation temperature is 96.5-97.5°C
  • the denaturation time is 15-25s
  • the extension time is 5-7min.
  • the pre-denaturation temperature is 97°C
  • the pre-denaturation time is 3 minutes
  • the denaturation temperature is 97°C
  • the denaturation time is 20s
  • the extension time is 6.5 minutes
  • the PCR amplification reaction system further includes a labeled template, a universal primer for amplification, a DNA polymerase, and a buffer;
  • the DNA polymerase is LongAmp Taq DNA polymerase
  • the concentration of the labeled template is 0.02-0.1 ng/ ⁇ l.
  • PCR amplification reaction program includes:
  • the PCR amplification reaction program includes:
  • the host removal includes free host DNA, degradation of host DNA, and removal of host DNA in sequence.
  • the free host DNA including the sample to be tested is treated with 0.1-0.5 w/v% saponin for 5-15 min;
  • degrading host DNA includes treating the sample to be tested with 0.3-1% (v/v) HL-SAN for 10-20 minutes after free host DNA.
  • the labeling includes the incubation reaction of the sample to be tested, which is subjected to host removal and genome extraction in turn, with FRM;
  • the procedure of the incubation reaction includes: first reacting at 29-31°C for 0.5-1.5 min, then reacting at 79-81°C for 0.5-1.5 min, and finally storing at 11-13°C;
  • the degree of the incubation reaction includes: first reacting at 30°C for 1 min, then reacting at 80°C for 1 min, and finally storing at 12°C.
  • a urinary metagenomic sample detection method based on a nanopore sequencing platform includes the above-mentioned library building method.
  • kits for building a library of urinary metagenomic samples based on a nanopore sequencing platform includes the components in the RPB004 kit, and also includes DMSO with a final concentration of 4% (v/v).
  • a test kit for urinary metagenomic samples based on a nanopore sequencing platform characterized in that the kit contains Saponin with a final concentration of 0.22% (w/v) and a final concentration of 0.49% (v/v).
  • HL-SAN also includes DMSO at a final concentration of 4% (v/v).
  • the present invention establishes an adjusted and improved host removal optimization process, and at the same time satisfies the removal of hosts for different infected urinary samples, and reduces the impact of host background heterogeneity in urinary samples, and has universal applicability , which is conducive to the establishment of a database of urinary samples from different infectious diseases and the output of sequencing results, and significantly reduces the failure rate of sequencing identification.
  • the present invention obtains a set of database construction system suitable for urinary infection samples, which has strong objectivity and high accuracy, reduces the difficulty of sequencing, and ensures the objectivity of sequencing results of urinary infection samples.
  • Fig. 1 is a flowchart of host removal, library construction, and sequencing and identification of urinary samples of the present invention
  • Figure 2 is the statistics of the proportion of each strain in the library constructed in the comparative example of the present invention.
  • Figure 3 is the statistics of the proportion of each strain in the library construction in Experimental Example 1 of the present invention.
  • Figure 4 is the statistics of the proportion of each strain in the 2% DMSO library in Experimental Example 2 of the present invention.
  • Fig. 5 is the statistics of the proportion of each strain in the 4% DMSO database in Experimental Example 2 of the present invention.
  • Figure 6 is the statistics of the proportion of each strain in the 5% DMSO database in Experimental Example 2 of the present invention.
  • Urinary samples are transported in a cold chain at 4°C and mixed thoroughly and gently in a biological safety cabinet. The same sample is enriched in two tubes. Principle: If urine sample is ⁇ 15mL, leave 5ml without going to the host, and the rest will go to the host; if urine sample ⁇ 15mL, divide it according to 1:5, 1 part does not go to the host, and 5 parts go to the host. The non-de-host and de-host urine samples were transferred to different sterile 50mL centrifuge tubes. The cap and the body of the tube were marked with the sample name and processing method.
  • Centrifuge at 12300g for 5min, discard the supernatant (don't touch the precipitate, you can keep ⁇ 500 ⁇ l supernatant), repeat the above process to enrich all urine samples. Add 1mL PBS to resuspend the pellet, and then transfer to a 2ml low adsorption centrifuge tube. You need to go to the host sample and perform the following operation two. If the host sample is not removed, first place it in a 4°C freezer for storage.
  • the nucleic acid mixing purification rules are as follows: if the host sample is enough For 45ng, take 45ng for purification; if the host sample is not enough 45ng, use the unremoved host sample to make up to 45ng and purify together; if it is not enough for the host plus the unremoved host nucleic acid, all are mixed and purified.
  • the third-generation sequencing platform GridION/MinION was used for sequencing.
  • urine-12 samples directly extracted nucleic acids with a concentration of 16.8ng/ul as high-concentration host samples into the testing process
  • urine-13 samples directly extracted nucleic acids with a concentration of 1.31ng/ul as low-concentration host samples into the testing process.
  • the present invention sets different saponin concentrations (2.5%, 1%, 0.5%, 0.22%, 0.125%) w/v and the dosage of HL-SAN enzyme (0.49%, 0.99%, 2.4%, 4.76%) v/v
  • Dehost verification experiments were carried out on a number of clinical samples, and the specific methods are as follows:
  • Table 1 shows that for high-concentration urine samples, urine-12 is directly extracted without going to the host, the nucleic acid concentration is 16.8ng/ul, and the Q-PCR result of the human internal reference primer has a CT value of 21.85; different saponin concentrations (2.5%, 1%) , 0.5%, 0.22%, 0.125%) w/v and the amount of HL-SAN enzyme (0.49%, 0.99%, 2.4%, 4.76%) v/v after removing the host, from the extraction concentration and Q-PCR results Although the effect of removing the host is obvious, the total amount of nucleic acid in most samples treated with (0.99%, 2.4%, 4.76%) v/v HL-SAN enzyme is less than 45ng, and it needs to be combined and purified with the nucleic acid that does not remove the host to meet the requirements of library construction.
  • urine-13 was extracted directly without going to the host, the concentration was 1.43ng/ul, and the Q-PCR result of human-source internal reference primers was 27.41; different saponin concentrations (2.5%, 1%, 0.5%, 0.22) %, 0.125%) w/v and the amount of HL-SAN enzyme (0.49%, 0.99%, 2.4%, 4.76%) v/v to the host and extract, from the extraction concentration and Q-PCR results to see the effect of the host They are all obvious, but (0.99%, 2.4%, 4.76%) v/v HL-SAN enzyme treatment of all samples nucleic acid concentration is zero, resulting in extraction failure.
  • the saponin concentration (0.22%, 0.125%) w/v and (0.49%) v/v of the present invention can not significantly increase the final amount of nucleic acid extracted by HL-SAN enzyme to the host, but it takes into account different nucleic acid concentrations or different infections.
  • the samples are universal, which can effectively balance the loss of bacteria in different urinary samples, the nucleic acid extraction rate, and the amount of input for database construction, so as to ensure the objective detection rate of subsequent sequencing identification results.
  • this section simulates the pathogen composition of urinary samples by mixing standard pathogenic microorganisms.
  • the standard pathogenic microorganisms were purchased from Microbial Community Standard (#D6306), contains 12 kinds of nucleic acid of pathogenic bacteria with different GC content, and their composition and GC content are shown in Table 2 below:
  • the basic library building kit used in the present invention is RPB004 kit, purchased from ONT company.
  • the experiment is based on ONT's RPB004 kit. All reagents including library building primers are derived from this kit.
  • the specific PCR amplification system for library construction is as follows, which serves as a comparative example of the present invention.
  • the specific PCR amplification program is:
  • the quality control standard is 4ng/ ⁇ l.
  • RPB004 reagent is only a basic library building kit of ONT, for special samples such as urology, its library building effect is not significant (such as the above-mentioned comparative example).
  • the research and development process of the above-mentioned comparative example The amplification system has been repeatedly optimized for multiple factors, including pre-denaturation temperature, denaturation temperature, denaturation time, and extension temperature and time, and finally determines the ideal amplification parameter system.
  • the quality control standard is 4ng/ ⁇ l.
  • Method A Add 0.1ng/0.25ng/0.5ng/1ng to each sample in a 0.2ml PCR tube with 4 gradients of the above standards and 1 ⁇ l FRM (purchased from ONT, included in the RPB004 kit) for Imitate the situation of a lower starting volume in practical applications.
  • the PCR reaction conditions are as follows:
  • the quality control standard is 4ng/ ⁇ l.
  • Method B is the same as Method A, except that in the PCR amplification reaction system, the dosage of 25% dimethyl sulfoxide is 8 ⁇ l (final concentration 4% v/v).
  • the difference is that in the PCR amplification reaction system, the dosage of 25% dimethyl sulfoxide is 10 ⁇ l (final concentration 5% v/v).
  • the average read length of the off-machine sequencing read length is 2.03kb, which is an increase of 14% compared to the comparison ratio, as shown in Figure 6.
  • the present invention aims at 31 randomly collected urine samples of clinically positive bacterial infections.
  • the host is removed, the database is constructed, and the sequencing identification is performed.
  • the clinical culture and GRADY method are used as controls, and the pathogenic bacteria that are inconsistent with the culture results Perform Qpcr verification again. Results All the database was successfully built and put on the computer. Table 11 below is the comparison result of the detailed identification result and the culture gold standard.
  • the detection effect is significantly better than the culture result and Grady detection result.
  • the clinical culture result of sample No. 152 is that only the genus of Corynebacterium can be identified, but the genus was not identified.
  • the sequencing result 1 was Corynebacterium striata, and the result 2 also detected Corynebacterium jeikeium, which was verified by Qpcr, and the result identified a clear specific pathogen; the clinical culture result of sample No. 199 was no Gram-positive bacillus.
  • the genus or species can be identified, the sequencing result 1 of the present invention is Lactobacillus crispatus (Gram-positive bacillus), and the species is identified as a clear specific pathogen.
  • the clinical culture result of 1 case was inconsistent with the sequencing result of the present invention.
  • the clinical culture result of sample No. 107 was Enterococcus faecium, but both the sequencing results and qPCR results of the present invention detected Enterococcus faecalis, and the sequencing results and qPCR results of the present invention contained Enterococcus faecium All of them were negative, and it was confirmed that Enterobacter faecalis was the dominant flora in the later clinically supported culture.
  • Pathogens detected 30 cases Detected pathogens after correction 31 cases No pathogen detected (negative) 0 cases The detected pathogen does not match the culture result 0 cases Only the genus is identified 0 cases Positive detection rate% 100%

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Abstract

提供了一种尿液样本宏基因组的去宿主方法,包括使用Saponin游离宿主DNA的步骤以及使用HL-SAN降解宿主DNA的步骤。

Description

基于纳米孔测序的泌尿宏基因组样本建库和检测方法
本申请要求于2019年12月17日提交中国专利局的申请号为201911297880.2、名称为“基于纳米孔测序平台的泌尿宏基因组样本建库和检测方法”,及2019年12月24日提交中国专利局的申请号为201911341615.X、名称为“基于纳米孔测序的泌尿宏基因组样本建库和检测方法”的中国专利申请的优先权,其全部内容通过引用结合在本申请中。
技术领域
本发明涉及生物技术领域,具体而言,涉及一种基于纳米孔测序平台的泌尿宏基因组样本的建库和检测方法。
背景技术
宏基因组测序克服了很多不能培养的病原体的鉴定弊端,被越来越多地应用于泌尿系统感染的临床样本鉴定中,特别是不明原因感染病原体鉴定及混合细菌感染。但是目前主流的高通量测序方法还是主要基于NGS二代测序方法,该方法鉴定通常从样本到结果的周期较长(>72h);测序读长短,增加生信拼接的难度和时长,同时短读长的准确度低;另一方面,大多数临床样本中,由于炎症反应等,往往存在大量的人类DNA,病原体DNA只占很少一部分,得到的测序数据中只有很小的一部分能够用于真正的物种鉴定,并且从大量的原始数据中通过生物信息学方法,过滤掉人类序列需要大量的计算能力且耗时较长,也会影响临床样本中低丰度病原体鉴定的敏感性。随着技术的不断发展,纳米孔测序以其包括超长序列读长、实时数据产生和生信分析和设备小巧便携等卓越的特征,为感染微生物病原体分析鉴定提供了巨大的希望。
目前基于纳米孔测序平台开发的快速鉴定流程中,英国的Grady团队开发的针对感 染样本的湿实验去宿主结合快速PCR条形码合并建库的流程,是目前最为成熟的技术路线。但该方法存在几个不足之处:由于去宿主步骤尽量去除了样本中绝大部分的宿主DNA,导致样本的提取浓度往往极低。例如,首先在对于尿液样本核酸提取过程中很多样本经Grady方法去宿主后,核酸提取浓度为零无法继续后续实验;其次建库过程中由于PCR失败而无法继续建库;更重要的是,由于建库过程中存在的PCR步骤,未能设计出很好的方案解决或降低扩增偏向性,导致对于一些GC含量高的细菌的鉴定出现严重问题,菌种丰度比例严重失衡。
鉴于尿液样本异质性非常大,此类样本无论是在去宿主阶段还是建库阶段都带来了很大挑战,现有技术中的方法都不足以很好解决这些问题。因此,现有技术中需要一种更为有效的泌尿宏基因组的去宿主、建库和测序方法。有鉴于此,特提出本发明。
发明内容
本发明的第一目的在于提供一种基于纳米孔测序平台的泌尿宏基因组样本的去宿主方法;
本发明的第二目的在于提供一种基于纳米孔测序平台的泌尿宏基因组样本的建库方法。
本发明的第三目的在于提供一种基于纳米孔测序平台的泌尿宏基因组样本测序鉴定方法。
为了实现本发明的上述目的,特采用以下技术方案:
一种尿液样本宏基因组的去宿主方法,其特征在于,所述去宿主方法包括:
尿液样本离心;
宿主DNA游离;
宿主DNA降解;
菌体收集;
进一步的,所述宿主DNA游离步骤包括:用终浓度0.1-0.5%(w/v)的Saponin游离宿主DNA 5-15min;所述宿主DNA降解步骤包括:用终浓度0.3-1%(v/v)的HL-SAN降解 宿主DNA 10-20min。
优选的,所述宿主DNA游离步骤包括:用终浓度0.22%(w/v)的Saponin游离宿主DNA 10min、;所述宿主DNA降解步骤包括:用终浓度0.49%(v/v)的HL-SAN降解宿主DNA 15min。
进一步的,所述样本离心步骤包括:取泌尿样本12300g离心后PBS重悬混匀;
进一步的,所述菌体收集步骤包括:PBS重悬后10000g再离心3min,弃上清获得去宿主样本;
在一些实施方式中,所述样本离心步骤包括:取泌尿样本,12300g离心5min;弃上清,250ul PBS重悬沉淀,混匀;所述宿主DNA游离步骤包括:加终浓度0.22%(w/v)的Saponin,室温10min;加350ul无菌水混匀,30s后加12ul 5M NaCl混匀;所述宿主DNA降解步骤包括:10000g离心5min后PBS重悬,加终浓度0.49%(v/v)的HL-SAN混匀,37℃,1300rpm孵育15min;所述菌体收集步骤包括:800ul PBS重悬后,10000g离心3min,弃上清获得去宿主样本。
一种尿液样本宏基因组的测序鉴定方法,其特征在于,所述方法包括:
去宿主步骤;
核酸提取步骤;
PCR扩增建库步骤;
上机测序步骤;
进一步的,所述去宿主步骤包括上述步骤。
在一些实施方式中,所述PCR扩增建库的反应体系中含有3-5%(v/v)的二甲基亚砜;
优选的,所述二甲基亚砜的含量为4%(v/v)。
进一步的,所述PCR扩增建库的反应程序中预变性温度为96.5-97.5℃,预变性时间为2-4min,变性温度为96.5-97.5℃,变性时间为15-25s,延伸时间为5-7min;
进一步的,所述PCR扩增的反应程序为:
Figure PCTCN2020079091-appb-000001
一种基于纳米孔测序平台的泌尿宏基因组样本的去宿主试剂盒,其特征在于,所述试剂盒包含终浓度为0.22%(w/v)的Saponin和终浓度为0.49%(v/v)的HL-SAN。
一种基于纳米孔测序平台的泌尿宏基因组样本的建库方法,将待检测样本依次经去宿主和提取基因组后进行标记,得到的带标记模板再PCR扩增进行建库;
所述PCR扩增的反应体系中含有3-5%(v/v)的二甲基亚砜;
所述PCR扩增的反应程序促进高GC含量模板的解旋和延伸。
进一步地,所述二甲基亚砜的含量为为4%(v/v)。
进一步地,所述PCR扩增的反应程序中预变性温度为96.5-97.5℃,预变性时间为2-4min,变性温度为96.5-97.5℃,变性时间为15-25s,延伸时间为5-7min;
进一步地,预变性温度为97℃,预变性时间为3min,变性温度为97℃,变性时间为20s,延伸时间为6.5min;
进一步地,所述PCR扩增的反应体系中还包括带标记模板、扩增通用引物、DNA聚合酶和缓冲液;
优选地,所述DNA聚合酶为LongAmp Taq DNA聚合酶;
优选地,所述带标记模板的浓度为0.02-0.1ng/μl。
进一步地,所述PCR扩增的反应程序包括:
Figure PCTCN2020079091-appb-000002
优选地,所述PCR扩增的反应程序包括:
Figure PCTCN2020079091-appb-000003
Figure PCTCN2020079091-appb-000004
进一步地,所述去宿主依次包括游离宿主DNA、降解宿主DNA和去除宿主DNA。
进一步地,游离宿主DNA包括待检测样本用0.1-0.5w/v%的皂苷处理5-15min;
优选地,降解宿主DNA包括待检测样本经游离宿主DNA后,用0.3-1%(v/v)的HL-SAN处理10-20min。
进一步地,所述标记包括将依次经去宿主和提取基因组后的待检测样本与FRM孵育反应;
优选地,所述孵育反应的程序包括:先29-31℃反应0.5-1.5min,再79-81℃反应0.5-1.5min,最后11-13℃保存;
优选地,所述孵育反应的程度包括:先30℃反应1min,再80℃反应1min,最后12℃保存。
一种基于纳米孔测序平台的泌尿宏基因组样本检测方法,包括上述的建库方法。
一种基于纳米孔测序平台的泌尿宏基因组样本的建库试剂盒,所述试剂盒包含RPB004试剂盒中组分,还包括终浓度4%(v/v)的DMSO。
一种基于纳米孔测序平台的泌尿宏基因组样本的检测试剂盒,其特征在于,所述试剂盒包含终浓度为0.22%(w/v)的Saponin和终浓度为0.49%(v/v)的HL-SAN,还包括终浓度4%(v/v)的DMSO。
与现有技术相比,本发明的有益效果为:
1)本发明通过对泌尿样本去宿主体系优化,建立了调整、改良的去宿主优化流程,同时满足不同感染泌尿样本的宿主去除,和降低泌尿样本宿主背景异质性的影响,具有普适性,利于不同感染疾病泌尿样本的建库和测序结果输出,显著降低测序鉴定的失败率。
2)本发明通过对建库体系优化,获得一套适于泌尿感染样本的建库体系,其客观性强、准确度高,降低测序难度,保证泌尿感染样本的测序结果客观性。
3)本发明通过对整个泌尿样本的去宿主和建库体系综合优化,保证了测序准确性性、客观性和便捷性,有效改善漏检和少测的常见假阴性问题,提高测序检出率,适于推广使用。
附图说明
为了更清楚地说明本发明具体实施方式或现有技术中的技术方案,下面将对具体实施方式或现有技术描述中所需要使用的附图作简单地介绍,显而易见地,下面描述中的附图是本发明的一些实施方式,对于本领域普通技术人员来讲,在不付出创造性劳动的前提下,还可以根据这些附图获得其他的附图。
图1为本发明泌尿样本的去宿主、建库和测序鉴定流程图;
图2为本发明对比例中建库各菌株占比结果统计;
图3为本发明实验例1中建库各菌株占比结果统计;
图4为本发明实验例2中2%的DMSO建库各菌株占比结果统计;
图5为本发明实验例2中4%的DMSO建库各菌株占比结果统计;
图6为本发明实验例2中5%的DMSO建库各菌株占比结果统计。
具体实施方式
下面将结合实施例对本发明的实施方案进行详细描述,但是本领域技术人员将会理解,下列实施例仅用于说明本发明,而不应视为限制本发明的范围。实施例中未注明具体条件者,按照常规条件或制造商建议的条件进行。
除非另有说明,本文中所用的专业与科学术语与本领域熟练人员所熟悉的意义相同。此外,任何与所记载内容相似或均等的方法或材料也可应用于本发明中。
本发明的整个实验流程如图1所示,本发明根据不同的尿液样本类型做了多重优化,具体实验步骤如下:
一、病原体富集流程
泌尿样本4℃冷链运输,在生物安全柜中充分轻柔的混匀,同一样本分两管富集。原则:若urine样本≥15mL,留5ml不去宿主,其余都去宿主;若urine样本≤15mL,则按1∶5进行分装,1份不去宿主,5份去宿主。不去宿主与去宿主urine 样本分别转移到不同的无菌50mL离心管中,管盖和管身都标上样本名称及处理方法。12300g离心5min,弃上清(不要触碰到沉淀,可以留<=500μl上清),重复上述过程,富集完所有urine样本。加1mL PBS重悬沉淀,再转移到2ml低吸附离心管中。需要去宿主样本进行如下操作二,不去宿主样本先置于4℃冰柜冷藏。
二、去宿主流程
2.1取上一步需要去宿主样本,12300g离心5min。
2.2小心弃掉上清(不要触碰到沉淀,可以留<=50μl上清),250ul PBS重悬沉淀,涡旋混匀,如有结块则用枪上下吹打充分混匀。
2.3加入200μl 0.5%Saponin,涡旋混匀,在旋转混匀仪上室温旋转10min。(0.5%Saponin现用现配,避光,4℃冷藏保质期7天)
2.4加入350ul无菌水,涡旋混匀,30s后加12ul 5M NaCl,立刻震荡混匀。
2.5 10000g离心5min小心去上清(不要触碰到沉淀,可以留<=50μl上清),100ul PBS重悬沉淀,再加Mix:101ul,涡旋混匀,如有结块则用枪上下吹打充分混匀。配置Mix:(100ul HL-SAN buffer,1ul HL-SAN)*N
2.6 37℃,1300rpm孵育15min。
2.7用800ul PBS重悬沉淀,涡旋混匀,如有结块则用枪上下吹打充分混匀。
2.8 10000g离心3min,小心弃上清(不要触碰到沉淀,可以留<=50μl上清)。
2.9加550uL PBS重悬沉淀,涡旋混匀,如有结块则用枪上下吹打充分混匀。
*样品珍贵,吸取的时候尽量减少损失
三、核酸提取
3.1.样本用550μL PBS重悬,将液体转移至Lysing Matrix E破碎管中;
3.2.在fastprep-5G仪器上设置破碎参数:6m/s,40s运行一次;
3.3. 14000g离心5min,吸取450μL上清,采用Maxwell RSC提取仪仪器:“Whole Blood DNA(CATALOG NUMBER AS1520)”提取流程。
四、样本混合纯化
鉴于泌尿样本的异质性,不同样本提取后核酸量的极大差异性,同时考虑后续测序建库的投入量要求,保障建库的高成功率,核酸混合纯化规则如下:若去宿主样本够45ng则取45ng纯化;若去宿主样本不够45ng则用未去宿主样本补到45ng一起纯化;若去宿主加未去宿主核酸都不够45ng,就全部混合纯化。
五.SQK-RPB004建库上机
5.1打断加接头:
5.1.1 0.2mlPCR管中每例样本加入3μl(1-5ng)模板DNA和1μl FRM,轻轻混匀离心;
5.1.2 PCR仪上反应:30℃1min,80℃1min,12℃∞;
5.2加barcode
5.2.1配制PCR mix体系(50μl):
Nuclease-free water 12ul
Tagmented DNA 4ul
RLB(01-12A) 1ul
LongAmp Taq 2X master mix(NEB) 25ul
25%DMSO 8ul
总体系 50ul
5.2.2 PCR仪反应,条件如下:
Figure PCTCN2020079091-appb-000005
5.2.3 QC:PCR结束后取1ul,用Qubit检测PCR产物浓度,小于4ng/ul的样本属与风险上机。
5.2.4不同样本产物混合:以最低样本的浓度为标准进行取样,其它样本等质量取样,混合成一管(目前是6个样本每个200ng)。
5.2.5纯化:加入0.6×beads,室温旋转孵育5min,瞬离放磁力架上去上清。
5.2.6 200μl新鲜配制的75%酒精洗2次beads。
5.2.7加入12μl 10mM Tris-HCl(50mM NaCl)pH 8.0洗脱液,室温旋转孵育2min,瞬离放磁力架上至澄清(注:取1μL Qubit定量)。
5.3加接头
往上述10μL样本中加入1μL RAP,室温反应10min。
5.4上机测序
采用三代测序平台GridION/MinION进行测序。
5.5生信分析
对测序下机数据进行生信分析。
以下结合具体的实施例来证明本发明所产生的技术效果。
实施例1 去宿主反应体系优化
鉴于尿液样本异质性非常大,实验室测试的114例尿液样本结果显示,在未去宿主的情况下提取核酸浓度在0ng/ul到几十ng/ul,40%的样本核酸提取浓度低于1ng/ul,再经过去宿主会导致后续提取建库的失败,因此在对去宿主的实验设计中需要考虑到后续实验的成功率,在此选择urine-12和urine-13作为极端样本说明解释。其中,urine-12样本直接提取核酸浓度16.8ng/ul作为高浓度宿主样本进入测试流程,urine-13样本直接提取核酸浓度1.31ng/ul作为低浓度宿主样本进入测试流程。本发明通过设置不同的皂苷浓度(2.5%、1%、0.5%、0.22%、0.125%)w/v和HL-SAN酶的用量(0.49%、0.99%、2.4%、4.76%)v/v对多例临床样本进行了去宿主验证实验,具体方法 如下:
1)取需尿液样本,12300g离心5min。
2)小心弃掉上清(不要触碰到沉淀,可以留<=50μl上清),250ul PBS重悬沉淀,涡旋混匀,如有结块则用枪上下吹打充分混匀。
3)添加不同浓度(2.5%、1%、0.5%、0.22%、0.125%)w/v的Saponin,涡旋混匀,在旋转混匀仪上室温旋转10min(Saponin现用现配,避光,4℃冷藏保质期7天)。
4)加入350ul无菌水,涡旋混匀,30s后加12ul 5M NaCl,立刻震荡混匀。
5)10000g离心5min小心去上清(不要触碰到沉淀,可以留<=50μl上清),100ul PBS重悬沉淀,再加Mix:101ul(含不同终浓度v/v的HL-SAN:0.49%、0.99%、2.4%、4.76%),涡旋混匀,如有结块则用枪上下吹打充分混匀。配置Mix:(100ul HL-SAN buffer,1ul HL-SAN)*N。
6)37℃,1300rpm孵育15min。
7)用800ul PBS重悬沉淀,涡旋混匀,如有结块则用枪上下吹打充分混匀。
8)10000g离心3min,小心弃上清(不要触碰到沉淀,可以留<=50μl上清)。
9)加550uL PBS重悬沉淀,涡旋混匀,如有结块则用枪上下吹打充分混匀。
试验结果如下表1。
表1 不同的皂苷浓度和HL-SAN酶的用量对不同尿液样本去宿主效果评估
Figure PCTCN2020079091-appb-000006
Figure PCTCN2020079091-appb-000007
表1表明,对于高浓度尿液样本urine-12不去宿主直接提取,核酸浓度为16.8ng/ul,人源内参引物Q-PCR结果CT值为21.85;不同的皂苷浓度(2.5%、1%、0.5%、0.22%、0.125%)w/v和HL-SAN酶的用量(0.49%、0.99%、2.4%、4.76%)v/v去宿主后,从提取浓度和Q-PCR结果来看去宿主的效果虽然明显,但(0.99%、2.4%、4.76%)v/v HL-SAN酶处理的样本大部分核酸总量<45ng,需要与不去宿主的核酸合并纯化才能满足 建库,可能会影响建库的成功率,合并纯化又会添加大量宿主基因进入样本会影响病原检出率,因此不推荐。皂苷浓度(2.5%、1%、0.5%、0.22%、0.125%)w/v和(0.49%)v/v HL-SAN酶处理的样本大部分核酸提取正常,可以正常建库。
对于低浓度尿液样本urine-13不去宿主直接提取,浓度为1.43ng/ul,人源内参引物Q-PCR结果CT值为27.41;不同的皂苷浓度(2.5%、1%、0.5%、0.22%、0.125%)w/v和HL-SAN酶的用量(0.49%、0.99%、2.4%、4.76%)v/v去宿主后提取,从提取浓度和Q-PCR结果来看去宿主的效果都很明显,但(0.99%、2.4%、4.76%)v/v HL-SAN酶处理的所有样本核酸浓度为零,导致提取失败。不同的皂苷浓度(2.5%、1%、0.5%、0.22%、0.125%)w/v和(0.49%)v/v HL-SAN酶处理的样本中,皂苷浓度≥0.5%,样本核酸浓度为零,导致提取失败。只有皂苷浓度(0.22%、0.125%)w/v和(0.49%)v/v HL-SAN酶处理的样本核酸提取正常,考虑该类型样本固有的低浓度核酸特性,难以获得不经合并直接建库的核酸量,因此皂苷浓度(0.22%、0.125%)w/v和(0.49%)v/v HL-SAN酶处理的样本可做为阳性结果,通过合并用于正常建库。
本发明通过对不同的皂苷浓度(2.5%、1%、0.5%、0.22%、0.125%)w/v和HL-SAN酶的用量(0.49%、0.99%、2.4%、4.76%)v/v对多例临床样本进行了去宿主实验,发现虽然尿液样本的异质性非常大,但Grady教授使用的5%的皂苷浓度和(2.4%、4.76%)v/v HL-SAN酶的用量对于尿液样本的处理导致下游核酸提取失败,进而会降低后续的建库和测序成功率。而本发明的皂苷浓度(0.22%、0.125%)w/v和(0.49%)v/v HL-SAN酶去宿主虽不能显著提高最终提取的核酸量,但兼顾了不同核酸浓度或不同感染泌尿样本,具有普适性,可有效平衡不同泌尿样本的菌量损失、核酸提取率以及满足建库投入量等多方因素,从而保证后续测序鉴定结果的客观检出率。
实施例2、建库体系的优化
为优化建库体系,尤其克服建库扩增的GC偏好性,本部分通过混合标准品病原微生物,模拟泌尿样本的病原体组成。标准品病原微生物购买自
Figure PCTCN2020079091-appb-000008
Microbial  Community Standard(#D6306),包含12种不同GC含量的病原菌的核酸,其组成及GC含量见下表2:
病原菌名称 拉丁名称 理论含量% GC值% 革兰氏染色
金黄色葡萄球菌 Staphylococcus aureus 12 32.9 +
单增生李斯特菌 Listeria monocytogenes 12 38 +
大肠杆菌 Escherichia coli 12 46.7 -
粪肠球菌 Enterococcus faecalis 12 37.5 +
枯草芽孢杆菌 Bacillus subtilis 12 43.9 +
肠炎沙门菌 Salmonella enterica 12 52.2 -
发酵乳杆菌 Lactobacillus fermentum 12 52.4 +
铜绿假单胞菌 Pseudomonas aeruginosa 12 66.2 -
酿酒酵母 Saccharomyces cerevisiae 2 38.3 真菌
新生隐球菌 Cryptococcus neoformans 2 48.3 真菌
本发明所用的基础建库试剂盒为RPB004试剂盒,购于ONT公司。
对比例
以ONT公司的RPB004试剂盒为基础进行试验,全部试剂包括建库引物均来源于该试剂盒。具体建库PCR扩增体系如下述,以此作为本发明的对比例。
方法:0.2ml PCR管中每例样本加入0.1ng/0.25ng/0.5ng/1ng共4个梯度的上述标准品和1μl FRM(包含在RPB004试剂盒中),用于模仿实际应用中较低起始量的情况。
具体的PCR扩增程序为:
Figure PCTCN2020079091-appb-000009
PCR结束后取1μl,用Qubit检测PCR产物浓度,质控标准为4ng/μl。
加入相当于体积0.6×beads,室温旋转孵育5min,瞬时离心放磁力架上去上清。200μl新鲜配制的75%酒精洗2次beads。加入12μl 10mM Tris-HCl(50mM NaCl)pH 8.0洗脱液,室温旋转孵育2min,瞬离放磁力架上至澄清。小心吸取11μl上清至1.5ml低吸附的离心管中。向上清10μl中加入1μl RAP,室温反应15min,准备上机。
按照牛津纳米孔上机流程:Priming and loading the SpotON Flow Cell进行上机。得到数据如下表3所示,百分比意为下机后某菌读长条数占所有读长条数的百分比,统计结果如图2所示:
通过该对比例得到数据如下表所示,数据结果见表3:
Figure PCTCN2020079091-appb-000010
从对比例上表结果可以看出来,当不同GC含量细菌共同扩增的时候,各种细菌的扩增随GC含量升高而降低,非常不利于宏基因组检测。对比例的文库平均值大小为1.78kb,较难发挥出ONT测序的长读长优势。
实验例1 建库pcr的温度和时间等参数优化
鉴于RPB004试剂仅是ONT公司的一种基础建库试剂盒,对于泌尿这种特殊样本而言,其建库效果并不显著(如上述对比例),本申请在研发过程中对上述对比例的扩增体系进行了多因素的反复优化,包括预变性温度、变性温度、变性时间以及延伸温度和时间等,最终确定理想扩增参数体系。
方法:0.2ml PCR管中每例样本加入0.1ng/0.25ng/0.5ng/1ng共4个梯度的上述标准品和1μl FRM(RPB004试剂盒中组分),用于模仿实际应用中较低起始量的情况。轻轻混匀离心,PCR仪上反应:30℃1min,80℃1min,12℃∞。
配制PCR mix体系(50μl)如下表4:
Nuclease-free water 22μl
Tagmented DNA 4μl
RLB(01-12A) 1μl
LongAmp Taq 2X master mix(NEB) 25μl
优化后的PCR反应条件如下:
Figure PCTCN2020079091-appb-000011
PCR结束后取1μl,用Qubit检测PCR产物浓度,质控标准为4ng/μl。
加入相当于体积0.6×beads,室温旋转孵育5min,瞬时离心放磁力架上去上清。200μl新鲜配制的75%酒精洗2次beads。加入12μl 10mM Tris-HCl(50mM NaCl)pH 8.0洗脱液,室温旋转孵育2min,瞬离放磁力架上至澄清。小心吸取11μl上清至1.5ml低吸附的离心管中。向上清10μl中加入1μl RAP,室温反应15min,准备上机。
按照牛津纳米孔上机流程:Priming and loading the SpotON Flow Cell进行上机。得到数据如下表5所示,百分比意为下机后某菌读长条数占所有读长条数的百分比,统计结果如表5所示:
Figure PCTCN2020079091-appb-000012
实验例1中可以看出,下机数据中序列的平均长度为2.22kb,高于对比例25%,说明改变扩增参数可以有效地延长扩增产物的平均长度,同时可以提高PCR产物浓度,利于测序分析,不过对于GC偏好问题改善不显著,详见图3。
实验例2 建库pcr的DMSO引入和浓度优化
一、方法A:0.2ml PCR管中每例样本加入0.1ng/0.25ng/0.5ng/1ng共4个梯度的上述标准品和1μl FRM(购于ONT,包含在RPB004试剂盒中),用于模仿实际应用中较低起始量的情况。
配制PCR mix体系(50μl)如下表6,DMSO终浓度2%(v/v):
Nuclease-free water 18μl
Tagmented DNA 4μl
RLB(01-12A) 1μl
LongAmp Taq 2X master mix(NEB) 25μl
25%二甲基亚枫DMSO 4μl
PCR仪反应,条件如下:
Figure PCTCN2020079091-appb-000013
PCR结束后取1μl,用Qubit检测PCR产物浓度,质控标准为4ng/μl。
加入相当于体积0.6×beads,室温旋转孵育5min,瞬时离心放磁力架上去上清。200μl新鲜配制的75%酒精洗2次beads。加入12μl 10mM Tris-HCl(50mM NaCl)pH 8.0洗脱液,室温旋转孵育2min,瞬离放磁力架上至澄清。小心吸取11μl上清至1.5ml低吸附的离心管中。向上清10μl中加入1μl RAP,室温反应15min,准备上机。
按照牛津纳米孔上机流程:Priming and loading the SpotON Flow Cell进行上机。测序分析得到数据如下表7所示,百分比意为下机后某菌读长条数占所有读长条数的百分比,统计结果如表7所示:
Figure PCTCN2020079091-appb-000014
可以看出,少量的DMSO(2%v/v)在尿液样本的宏基因组扩增中略有改善GC含量偏多菌株优选扩增的现象,但效果并不显著,详见图4;同时,平均读长长度为2.6kb,高于对比例46%。
二、方法B,与A方法相同,不同的是,PCR扩增的反应体系中,25%二甲基亚枫用量为8μl(终浓度4%v/v)。
测序分析得到数据如下表8所示,统计结果如表8所示:
Figure PCTCN2020079091-appb-000015
从上表结果可以看出,DMSO的用量达到终浓度4%,当不同GC含量细菌共同扩增的时候,各种细菌的测序量趋于平衡(见图5),并在理论占比范围(12%)上下波动,有利于宏基因组检测,同时测序平均读长大小为2.18kb,比对比例长度提高了22%。
三、与A方法相同,不同的是,PCR扩增的反应体系中,25%二甲基亚枫用量为10μl(终浓度5%v/v)。
测序分析得到数据如下表9所示,统计结果如表9所示:
  0.1ng 0.25ng 0.5ng 1ng
产物浓度 9.01ng/ul 5.46ng/ul 30ng/ul 34.6ng/ul
Staphylococcus aureus 2.76% 0.82% 1.56% 2.64%
Enterococcus faecalis 2.27% 1.39% 2.82% 4.24%
Listeria monocytogenes 2.90% 1.54% 3.18% 5.15%
Bacillus subtilis 5.08% 4.19% 7.96% 9.50%
Escherichia coli 11.00% 10.7% 20.33% 20.20%
Salmonella enterica 10.43% 10.87% 16.65% 15.92%
Lactobacillus fermentum 9.58% 9.41% 10.34% 9.51%
Pseudomonas aeruginosa 52.79% 58.40% 33.00% 28.66%
可以看出,当加大了DMSO用量达到终浓度为5%时,过于扩增了GC含量高的菌,导致GC含量低的菌的扩增收到了抑制,并不适合宏基因组的扩增,下机的测序读长长度平均读长为2.03kb,比对比例提高了14%,具体见图6。
综上,不同浓度的DMSO对扩增结果影响极其显著,过高(5%)或高低(2%)的DMSO浓度对于泌尿样本的建库效果差异显著,本实验确定4%的DMSO浓度最适于泌尿样本的建库。
实验例3 临床样本建库验证
采集医院检验科收集的临床泌尿样本,每一份均有临床尿培养结果。样本4℃冷链运输,在生物安全柜中充分轻柔的混匀12300g离心5min,弃上清加1mLPBS重悬沉淀,再转移到2ml低吸附离心管中。
1去宿主:
a)取上一步需要去宿主样本,12300g离心5min。
b)小心弃掉上清(不要触碰到沉淀,可以留<=50μl上清),250μl PBS重悬沉淀,涡旋混匀,如有结块则用枪上下吹打充分混匀。
c)加入终浓度0.22%(w/v)的Saponin,涡旋混匀,在旋转混匀仪上室温旋转10min。加入350μl无菌水,涡旋混匀,30s后加12μl 5M NaCl,立刻震荡混匀。
d)10000g离心5min小心去上清(不要触碰到沉淀,可以留<=50μl上清),100μl PBS重悬沉淀,再加终浓度0.49%(v/v)的HL-SAN,37℃,1300rpm孵育15min。
e)用800μl PBS重悬沉淀,涡旋混匀。
2 MP FastPrep-245G破壁处理
a)临床样本去宿主处理后,直接用移液器吹打混匀后转移至MP Lysing Matrix E tube中,并按照MP FastPrep PROGRAM MANUALLY要求进行破壁处理,SPEED为6.0m/sec,ADAPTER为QuickPrep,TIME为40s,Lysing Matrix为E。
b)用Eppendorf 5424R型号离心机,14000rpm离心10min,转移上清进行下一步基因组的提取。
3 Maxwell RSC自动核酸提取
a)首先打开Maxwell RSC提取仪所连接的电脑,然后打开Maxwell RSC提取仪仪器。
b)选择其中“Whole Blood DNA(CATALOG NUMBER AS1520)”对应的程序,按照提示进行提取。
c)Qubit测定浓度。
4 建库和上级测序分析
分别按照实验例2的方法B和对比例的方法进行对比检测,验证本发明的临床实验效果。具体结果如下表10:实验例2方法B和对比例方法检测结果对比
Figure PCTCN2020079091-appb-000016
Figure PCTCN2020079091-appb-000017
结果表明,本发明方法在扩增产物浓度及产物平均值上均优于对比例,检出结果与临床培养的阳性一致率上。本发明方法也明显优于对比例:对比例临床对于27号样本、40号样本、60号样本均无法检测到混合感染,而6号样本尿液样本中可能细菌含量较少,比例无法检出,因此检出率=9/13*100%=69%;而本发明均全面且准确检出,其检出率=13/13*100%=100%,显著优于对比例。
实施例3 临床样本的全流程检测
本发明针对随机收取的临床培养阳性的细菌性感染尿液样本31例,按照本发明上述方法进行去宿主、建库和测序鉴定,以临床培养、GRADY方法作为对照,对与培养结果不一致的病原菌再进行Qpcr验证。结果全部建库上机成功,下表11是详细鉴定结果与培养金标准的比对结果。
表11.本发明流程病原体检出结果、Grady鉴定结果及培养金标准详细比对表
Figure PCTCN2020079091-appb-000018
Figure PCTCN2020079091-appb-000019
可见,采用本发明流程能够检出的病原体为30例,且检测效果显著优于培养结果和Grady检测结果,示例,152号样本临床的培养结果为棒杆菌属只能鉴定到属,未能鉴定到种,而本发明测序结果1为纹带棒状杆菌,同时结果2还检出Corynebacterium jeikeium,并经Qpcr验证,结果鉴定到种明确的具体病原;199号样本临床培养结果为革兰阳性杆菌未能鉴定到属或种,本发明测序结果1为卷曲乳杆菌(革兰阳性杆菌), 结果鉴定到种明确具体病原。1例临床培养结果与本发明测序结果不符,107号样本临床培养结果为屎肠球菌,但本发明测序结果和qPCR结果都检出粪肠球菌,且本发明测序结果和qPCR结果中屎肠球菌都为阴性,后期经临床佐证培养结果中确是以粪肠杆菌为优势菌群。而Grady去宿主及建库流程对于泌尿样本的检出失败率较高,本发明的去宿主及建库流程的针对泌尿样本阳性检出率分别为96.8%(矫正后检出比例为100%)(31例/31例),如表12所示,建库成功率为100%。相比之下,本发明对于样本的普适性更强,适于不同来源泌尿样本,显著提高了临床阳性样本的测序检出率。
表12.本发明流程病原体检出结果与阳性检出率表
  中段尿(31例)
检出病原体 30例
矫正后的检出病原体 31例
未检出病原体(阴性) 0例
检出病原体与培养结果不符 0例
只鉴定到属 0例
阳性检出率% 100%
尽管已用具体实验例来说明和描述了本发明,然而应意识到,在不背离本发明的精神和范围的情况下可以作出许多其它的更改和修改。因此,这意味着在所附权利要求中包括属于本发明范围内的所有这些变化和修改。

Claims (10)

  1. 一种尿液样本宏基因组的去宿主方法,其特征在于,所述去宿主方法包括:
    尿液样本离心;
    宿主DNA游离;
    宿主DNA降解;
    菌体收集;
    所述宿主DNA游离步骤包括:用终浓度0.1-0.5%(w/v)的Saponin游离宿主DNA5-15min;
    所述宿主DNA降解步骤包括:用终浓度0.3-1%(v/v)的HL-SAN降解宿主DNA10-20min。
  2. 权利要求1所述的尿液样本宏基因组的去宿主方法,其特征在于:
    所述宿主DNA游离步骤包括:用终浓度0.22%(w/v)的Saponin游离宿主DNA 10min;
    所述宿主DNA降解步骤包括:用终浓度0.49%(v/v)的HL-SAN降解宿主DNA 15min。
  3. 权利要求2所述的尿液样本宏基因组的去宿主方法,其特征在于:
    所述样本离心步骤包括:取泌尿样本12300g离心后PBS重悬混匀;
    所述菌体收集步骤包括:PBS重悬后10000g再离心3min,弃上清获得去宿主样本。
  4. 权利要求3所述的尿液样本宏基因组的去宿主方法,其特征在于:
    所述样本离心步骤包括:取泌尿样本,12300g离心5min,弃上清,250ul PBS重悬沉淀,混匀;
    所述宿主DNA游离步骤包括:加终浓度0.22%(w/v)的Saponin,室温10min,加350ul无菌水混匀,30s后加12ul 5M NaCl混匀;
    所述宿主DNA降解步骤包括:10000g离心5min后PBS重悬,加终浓度0.49%(v/v)的HL-SAN混匀,37℃,1300rpm孵育15min;
    所述菌体收集步骤包括:800ul PBS重悬后,10000g离心3min,弃上清获得去宿主样本。
  5. 一种尿液样本宏基因组的测序鉴定方法,其特征在于,所述方法包括:
    去宿主步骤;
    核酸提取步骤;
    PCR扩增建库步骤;
    上机测序步骤;
    所述去宿主步骤为权利要求1-4任一所述的步骤。
  6. 权利要求5所述的尿液样本宏基因组的测序鉴定方法,其特征在于,所述PCR扩增建库的反应体系中含有3-5%(v/v)的二甲基亚砜;优选的,所述二甲基亚砜的含量为4%(v/v)。
  7. 权利要求6所述的尿液样本宏基因组的测序鉴定方法,其特征在于,所述PCR扩增建库的反应程序中预变性温度为96.5-97.5℃,预变性时间为2-4min,变性温度为96.5-97.5℃,变性时间为15-25s,延伸时间为5-7min。
  8. 根据权利要求7所述的尿液样本宏基因组的测序鉴定方法,其特征在于,所述PCR扩增的反应程序为:
    Figure PCTCN2020079091-appb-100001
  9. 一种基于纳米孔测序平台的泌尿宏基因组样本的去宿主试剂盒,其特征在于,所述试剂盒包含终浓度为0.22%(w/v)的Saponin和终浓度为0.49%(v/v)的HL-SAN。
  10. 一种基于纳米孔测序平台的泌尿宏基因组样本的检测试剂盒,其特征在于,所述试剂盒包含终浓度为0.22%(w/v)的Saponin和终浓度为0.49%(v/v)的HL-SAN,还包括终浓度4%(v/v)的DMSO。
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