EP1495143A1 - Detection de mycobacteries dans des materiaux cliniques - Google Patents

Detection de mycobacteries dans des materiaux cliniques

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Publication number
EP1495143A1
EP1495143A1 EP03729922A EP03729922A EP1495143A1 EP 1495143 A1 EP1495143 A1 EP 1495143A1 EP 03729922 A EP03729922 A EP 03729922A EP 03729922 A EP03729922 A EP 03729922A EP 1495143 A1 EP1495143 A1 EP 1495143A1
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EP
European Patent Office
Prior art keywords
seq
detection
pair
mycobacteria
rrna
Prior art date
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EP03729922A
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German (de)
English (en)
Inventor
Franz-Christoph Bange
Erik Christian BÖTTGER
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Cytonet GmbH and Co KG
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Cytonet GmbH and Co KG
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Publication of EP1495143A1 publication Critical patent/EP1495143A1/fr
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    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Q—MEASURING 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
    • C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
    • C12Q1/68—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving nucleic acids
    • C12Q1/6876—Nucleic acid products used in the analysis of nucleic acids, e.g. primers or probes
    • C12Q1/6888—Nucleic acid products used in the analysis of nucleic acids, e.g. primers or probes for detection or identification of organisms
    • C12Q1/689—Nucleic acid products used in the analysis of nucleic acids, e.g. primers or probes for detection or identification of organisms for bacteria
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Q—MEASURING 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
    • C12Q2600/00—Oligonucleotides characterized by their use
    • C12Q2600/166—Oligonucleotides used as internal standards, controls or normalisation probes

Definitions

  • the present invention relates to a method for the specific detection of mycobacteria and for differentiating the Mycobacterium tuberculosis complex and Mycobacterium avium from other mycobacteria in clinical material.
  • Tuberculosis is a worldwide infectious disease that is chronic and costs more lives each year than any other bacterial infection.
  • Tuberculosis is particularly localized in the lungs, less often in the cervical lymph nodes, intestine or skin.
  • the very different clinical courses of tuberculosis therefore make an exact description of the disease state and a quick diagnosis necessary, especially at early stages of the disease.
  • Mycobacteri um tuberculosis and very rarely Mycobacterium bovis are generally summarized under the term "Mycobacterium tuberculosis complex”.
  • Non-tuberculous mycobacteria lead to an additional worsening in patients suffering from, for example, cystic fibrosis the clinical picture in the area of the lungs (1, 2, 16).
  • the non-tuberculous mycobacteria observed in clinical practice include: Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium kansasii, Mycobacterium marinum, Mycobacterium fortui tum, Mycobacterium chelonae and Mycobacterium abscessus (4).
  • the diagnosis of mycobacteria in clinical material should ideally allow specific detection of tuberculous and non-tuberculous mycobacteria.
  • PCR polymerase chain reaction
  • Genus-specific methods are used to differentiate a mycobacterial infection from other infections.
  • Known genus-specific methods target the 16S rRNA gene or the gene of the 65 kDa “heat shock” protein.
  • a subsequent specific identification of some types of mycobacteria is carried out using conserved hybridization probes (5, 12).
  • the amplified genes are sequenced ( 6) or an analysis using restriction enzymes is carried out (15).
  • the specific DNA regions that are used for the species-specific detection of the M. tuberculosis complex by means of PCR include, for example, IS 6110, the genes of the 38 kDa protein, the genes of the MBP 64 protein and the regions mtp40 or pMTb4.
  • diagnostic kits which are mostly only suitable for diagnosing the M. tuberculosis complex.
  • kits are offered, for example, by Roche-Amplicor TM, Geneprobe TM or Abbot TM.
  • the molecular biological methods that are carried out for this purpose include, on the one hand, the duplication of the nucleic acid to be detected (target amplification), for example by means of PCR, by transcription-based isothermal DNA synthesis (TMA), by the ligase chain reaction (LCR) or by the isothermal strand displacement amplification (SDA), on the other hand the duplication of the signaling component (signal amplification), such as by the isothermal Qß replication.
  • target amplification for example by means of PCR
  • TMA transcription-based isothermal DNA synthesis
  • LCR ligase chain reaction
  • SDA isothermal strand displacement amplification
  • the l ⁇ S rRNA gene is already used for the detection and identification of various human-pathogenic mycobacteria by means of PCR (7).
  • an algorithm for the specific duplication of a 1000 bp fragment of the mycobacterial 16S rRNA by means of an unspecific primer and a genus-specific primer for mycobacteria is proposed.
  • genus-specific oligonucleotide probes are used which hybridize with the spaceted fragment.
  • species-specific hybridization probes are used, whereby the mycobacterial species M. tuberculosis complex and M. avium can be differentiated from other types of bacteria using the same amplified fragment (5).
  • DNA extracted from clinical samples contains contaminants that often lead to enzyme-based amplification, especially PCR, being inhibited.
  • detection methods known to date there is a great risk that a negative result will be obtained even though the patient actually has a mycobacterial infection.
  • existing tuberculosis is overlooked. Therefore, there has long been a need to develop a control system, the so-called "false negative" finding de excludes in the detection procedure (inhibition control).
  • fluorimetric measurements especially when used as part of the real-time PCR method, represent a fast and sensitive method for the detection of amplified gene fragments.
  • real-time fluorimetry was used to detect M. tuberculosis in expectorates using the TaqMan TM system.
  • the LightCycler TM system from Röche Molecular Biochemicals which is an embodiment of real-time PCR, has now also been used to detect M. bovis in Rinderstuhl and to detect mutations in rifampin or isoniazid resistance in M. tuberculosis (11, 13). In these two studies, the multiplied fragments were typically 200 base pairs in length. Due to the high throughput of a LightCycler TM system, it has been assumed up to now that multiplication of larger DNA fragments of mycobacteria is difficult or impossible due to the high CG nucleotide content of approx. 65% up to 75% occurring in mycobacteria.
  • genus-specific region II is from the prior art II ", known on the 16S rRNA gene of mycobacteria, whereby by means of a specific hybridization probe pair and a melting curve analysis, a large number of mycobacterial species can be distinguished from other bacterial species and other microorganisms due to a higher melting point of the probe pair (6)
  • certain types of mycobacteria such as M. triviale, M. agri, M. Xenopi or M. chitae also have a low melting point, so that, according to the prior art, the mycobacteria are clearly differentiated from non-mycobacteria, especially in a single procedural step is not possible at all.
  • the technical problem of the present invention is to provide an improved method, in particular a particularly fast and at the same time more specific detection of mycobacterial infections in clinical material of various origins and the identification of the species M. tuberculosis complex and / or M. avium in enables a common verification procedure.
  • the present invention solves the technical problem by providing a method for joint, specific detection of a mycobacterial rieninfediction and the Mycobacterium tuberculosis complex and / or Mycobacterium avium compared to other types of mycobacteria in clinical material, wherein (a) microbial DNA is extracted from the clinical material and then
  • At least one fragment of the 16S rRNA gene from the microbial DNA is amplified with a primer pair comprising the nucleotide sequences SEQ ID NO: 1 / SEQ ID NO: 5 or with two primer pairs, the one primer pair containing the nucleotide sequences SEQ ID NO: 2 / SEQ ID NO: 3 and the other pair of primers is used immediately before or after or simultaneously and the nucleotide sequences include SEQ ID NO: 4 / SEQ ID NO: 5, is amplified and then
  • the at least one amplified 16S rRNA gene fragment is detected by means of at least one pair of labeled hybridization probes which hybridize with hypervariable species-specific regions of the 16S rRNA fragment of mycobacteria, the pair of labeled hybridization probes for detection of the M. tuberculosis complex includes the nucleotide sequences SEQ ID NO: 6 / SEQ ID NO: 7 or the pair of complementary sequences thereof, and the pair of labeled hybridization probes for the detection of M.
  • avium contain the nucleotide sequences of SEQ ID NO: 8 / SEQ ID NO: 9 or the pair of the complementary sequences thereof, and then, simultaneously or immediately before (d) the at least one amplified 16S rRNA gene fragment is detected by means of a pair of labeled hybridization probes which hybridizes with the genus-specific region III of the 16S rRNA fragment, the pair having the nucleotide sequences SEQ ID NO: 10 / SEQ ID NO: 11 or the pair of complementary sequences thereof, and wherein
  • steps (e) the specific detection of the mycobacteria genus, and the detection of the M. tuberculosis complex and / or of M. avium in steps (c) and (d) is carried out by means of melting curve analysis.
  • the invention therefore advantageously provides that the detection of mycobacteria as a genus together with the species-specific detection of M. tuberculosis complex is made possible in a uniform common procedure.
  • the invention also enables a common uniform specific detection of the genus Mycobacterium together with the species-specific detection of M. avium.
  • the invention also enables the joint specific detection of bacteria of the genus ycojacterium together with the species-specific detection of M. tuberculosis complex and M. avium.
  • a major advantage of the method according to the invention is that in the combined detection method used to diagnose mycobacterial infections, both an existing mycobacterial infection compared to other microbial infections and an existing tuberculosis compared to non-tuberculous infections are clear and reliable can be recognized. This proof was not possible in such an advantageous manner according to the prior art.
  • the unequivocal detection of a mycobacterial infection compared to other microbial infections takes place by analyzing the melting temperatures of the hybridization of the genus-specific hybridization probe pair, which contains the nucleotide sequences SEQ ID NO: 10 / SEQ ID NO: 11 or the pair of the complementary sequences thereof, with the Genus-specific region III of the 16S rRNA gene took place.
  • mycobacterial strains are characterized by melting temperatures of at least 55 ° C., in particular 55 ° C. and 61.5 ° C.
  • the mycobacterial strain M. chelonae can be clearly identified compared to all other mycobacterial strains, which in particular have a melting temperature of 61.5 ° C, and a mycobacterial infection by M. chelonae can be detected ,
  • the method according to the invention permits, in addition to the clear and reliable detection of a tuberculous infection, the clear and reliable detection of a non-tuberculous infection triggered by M. avium.
  • strains of the M. tuberculosis complex are distinguished by melting temperatures of at least 55 ° C., in particular 64 ° C.
  • the unequivocal detection of a tuberculous infection by M. avium takes place by analyzing the melting temperatures of the hybridization of the type-specific hybridization probe pair for M. avium, the nucleotide sequences SEQ ID NO: 8 / SEQ ID NO: 9 or the pair of complementary sequences of which includes the species-specific region of the 16S rRNA gene.
  • M. avium is characterized by melting temperatures of at least 55 ° C., in particular 6.1 ° C.
  • the above-mentioned method is preferably carried out with an internal standard according to the invention in the form of artificial plasmids, control plasmids, for identifying so-called “false-negative” findings.
  • a first part of the extracted microbial DNA complies with the aforementioned Method with steps (a) to (e) is subjected and a second part of the extracted microbial DNA in a parallel to the aforementioned method approach (a ') is mixed with at least one artificial plasmid, preferably subcloned in pGEM-T, which serves as an internal standard, the artificial plasmid comprising a genus-specific region III of the 16S rRNA with a modified nucleotide sequence, and then
  • the multiplied 16S rRNA fragments are detected by means of a pair of labeled hybridization probes which hybridize with the modified genus-specific region III, the pair of labeled hybridization probes comprising the nucleotide sequences SEQ ID NO: 10 / SEQ ID NO: 11 and where (d ') during the detection the specific detection of the 16S rRNA fragments of mycobacteria and the modified 16S rRNA fragments of the internal standard is carried out by means of melting curve analysis.
  • steps (a), (b), (c), (d) and (e) of the aforementioned method are carried out, the at least one artificial plasmid in step (a) using the total extracted microbial DNA is mixed and, after application according to step (b), the detection and melting curve analysis to detect the multiplied 16S rRNA fragments of mycobacteria and the modified 16S rRNA fragments of the internal standard, in particular simultaneously, according to steps (c ') and (d') is carried out.
  • control plasmid in the detection method according to the invention, it is advantageously possible to check the success of the amplification reaction already during the detection reaction of mycobacteria in order to obtain a reliable and clear result particularly quickly.
  • so-called “false-negative” findings in the case of inhibition of amplification are practically excluded by using the plasmid according to the invention as an internal standard.
  • the specificity and selectivity of the method according to the invention are thus significantly increased compared to the prior art.
  • the formulations “comprising a primer pair or comprising the nucleotide sequences”, “comprising a pair of hybridization probes or comprising the nucleotide sequences” or the like mean that the respective nucleotide sequences or the pair of nucleotide sequences each have the nucleotide sequences referred to / has, that is to say that these nucleotide sequences or the pair thereof consist / consist of the specifically named nucleotide sequence alone or optionally comprise / comprise further sequences.
  • Mycojacteriu-n tuberculosis complex refers to the tuberculous mycobacterial species Mycobacterium tuberculosis, in particular the strain H37Rv, and Mycobacterium bovis, in particular the R99 strain, these strains causing the disease tuberculosis, and the BCG Pasteur strain of Mycobacterium bovis.
  • the term "tubercular” describes a property which relates to Mycobacterium tuberculosis, in particular the strain H37Rv, and Mycobacterium bovis, in particular the strain R99, in the narrower sense and to the strain BCG Pasteur of Mycobacterium bovis in refers to the wider sense and causes the clinical picture of tuberculosis.
  • Mycobacterium avium is understood to mean the non-tuberculous Mycobacterium species Mycobacterium avium, in particular the strain ATCC35712, and their subspecies Mycobacterium paratuberculosis, in particular the strain Pat.6783.
  • non-tuberculous is understood to mean a property which is related to a disease other than tuberculosis and is in particular a mycobacteriosis.
  • clinical material is understood to mean clinical samples such as sputum, bronchial lavage, gastric juice, urine, stool, cerebrospinal fluid, bone marrow, blood or biopsies, in particular punctate biopsies, for example from cervical lymph nodes.
  • modified nucleotide sequence is understood to mean a nucleic acid sequence which is derived from its original sequence, ie the wild-type sequence, by exchange, inversion, deletion or addition of at least one nucleotide, including an unusual or synthetic nucleotide , in at least one nucleotide, preferably in two nucleotides.
  • modified is understood to mean a property which relates to a "modified nucleotide sequence”.
  • the amplification of the gene fragments of the 16S rRNA gene is carried out by means of the polymerase chain reaction (PCR).
  • the amplification is preferably carried out by real-time PCR (rapid cycle PCR).
  • real-time PCR rapid cycle PCR
  • the amplification is particularly preferably carried out in a LightCycler TM system from Röche Molecular Biochemicals, which is an embodiment of the real-time PCR.
  • the PCR starting mixture in addition to the polymerase, the nucleotides, the buffer solutions and the primers, also hybridization probes which specifically bind to the desired PCR amplification products are added.
  • two sequence-specific oligonucleotide probes are used, which are labeled with different dyes.
  • the sequences of the Labeled hybridization probe pairs according to the invention are selected such that they hybridize to the target sequences of the amplified DNA fragment in such a way that in particular the 3 'end of one probe is close to the 5' end of the other probe, as a result of which the two dyes be brought into close proximity to one another, in particular the distance between the two probes is between 1 and 5 nucleotides.
  • FRET fluorescence resonance energy transfer
  • the FRET system quantitative measurements of the amount of amplified DNA fragments are provided by the FRET system.
  • the hybridization probes selected according to the invention can bind quantitatively, ie stoichiometrically, to the amplified fragments.
  • the quantitative hybridization is particularly dependent on the temperature and the degree of homology of the oligonucleotide probes used with the detected sequence on the amplified fragment.
  • the aforementioned fluorimetric detection of specific DNA sequences in the amplified fragments is carried out after amplification of the fragments by means of conventional PCR.
  • the fluorimetric de- tection carried out in a real-time PCR during the amplification reactions for example the increase in DNA produced can be tracked as an increase in the fluorescence signal.
  • the specific detection of species-specific and / or genus-specific regions in the amplified DNA fragment takes place after the end of the amplification reaction, the hybridization probe pair, preferably a FRET pair, being hybridized the regions to be detected, the temperature is changed in the course of a melting curve analysis, preferably continuously increased, and at the same time the fluorescence emitted as a function of the temperature is measured. In this way, a melting temperature is determined at which the hybridization probes, in particular the FRET pair used, no longer hybridize to the region of the amplified DNA fragment to be detected.
  • the essential aspect of a melting curve analysis is that if there are mismatches between the pair of hybridization probes used and the target region on the approved DNA fragment, the measured melting point is reduced.
  • the regions of DNA fragments whose sequences differ only slightly, in particular by one or a few point mutations, in the nucleotide sequence are identified with hybridization probes, in particular with a FRET pair.
  • the 16S rRNA gene of mycobacteria advantageously has both conserved and highly variable regions which, for example, permit genus-specific amplification of DNA fragments using genus-specific primers.
  • the aforementioned methods of fluorescence detection are therefore used in conjunction with the melting curve analysis for the specific detection of the genus-specific region III and the hypervariable species-specific regions of the M. tuberculosis complex and M. avium on the 16S rRNA gene.
  • primer pairs are additionally shown schematically, which are used to amplify the selected species-specific or genus-specific regions.
  • the primer pair comprising the nucleotide sequences SEQ ID NO: 1 and SEQ ID NO: 5 is used to amplify the gene-specific region III 16S rRNA gene from mycobacteria.
  • the primer pair consists of degenerate or mutated sequences or fragments thereof, each of which hybridizes with the nucleotide sequences SEQ ID NO: 1 and SEQ ID NO: 5, from which they are derived, where in each case there is a degree of homology of at least 90%, preferably at least 95%, particularly preferably at least 98%.
  • the 1000 bp long fragment amplified with the aforementioned primer pair contains both the conserved genus-specific region III and the highly variable species-specific regions of the M. tuberculosis complex and M. avium.
  • the additional or alternative use of two further primer pairs is also provided, a primer pair amplifying a 300 bp fragment in particular of the l ⁇ S rRNA gene from mycobacteria which contains specific regions of the M. tuberculosis complex and M. avium, this primer pair consisting of the nucleotide sequences SEQ ID NO: 2 / SEQ ID NO: 3, and the second primer pair amplifying a 100 bp long fragment of the same gene which amplifies the Contains genus-specific region III, this primer pair comprising the nucleotide sequences SEQ ID NO: 4 / SEQ ID NO: 5.
  • the two primer pairs consist of the pairs of degenerate or mutated sequences or fragments thereof, each with the nucleotide sequence pairs SEQ ID NO: 2 / SEQ ID NO: 3 and SEQ ID NO: 4 / SEQ ID NO: hybridize 5, of which they are derived, in each case a degree of homology of at least 90 1%, preferably at least 95%, more preferably consists of at least 98%.
  • a pair of labeled hybridization probes is used to detect the aforementioned amplified 16S rRNA fragments of mycobacteria which contain the genus-specific region III and / or the species-specific regions of the M. tuberculosis complex and M. avium of the conserved genus-specific region III, which pair contains the nucleotide sequences SEQ ID NO: 10 / SEQ ID NO: 11 or the complementary sequences thereof.
  • the detection of the aforementioned '16S rRNA fragments containing the species-specific regions is carried out with at least one pair of labeled hybridization probes, the labeled hybridization probe pairs preferably being in the form of FRET pairs.
  • the type-specific hybridization probe pairs according to the invention are used for the specific detection of the mycobacterial species M. tuberculosis complex and M.
  • the rhodamine derivative is LightCycler-Red 640; in further preferred variants of the aforementioned embodiment, the rhodamine derivative is LightCycler-Red 705; in further preferred variants of the aforementioned embodiment, the rhodamine derivative is Cy5.
  • the same donor-acceptor dyes are used for labeling the hybridization probe pairs, preferably fluorescein / LightCycler-Red 640, the melting curve analysis using the species-specific probe pair to detect mycobacteria in time or spatially separated from the melting curve analysis using one of the species-specific hybridization probe pairs for the detection of the M. tuberculosis complex or of M. avium, in particular in parallel approaches.
  • the melting curve analysis using the species-specific probe pair for the detection of mycobacteria preferably with fluorescein / LightCycler-Red 640 is marked, temporally and spatially together in an approach with melting curve analysis with one of the species-specific hybridization probe pairs, which is preferably labeled with Fluorescein / LightCycler-Red 705, for the detection of the M. tuberculosis complex or of M. avium takes place, preferably in LightCycler TM system the fluorescence of the genus-specific probe pair with one photodetector channel and the fluorescence of a species-specific probe pair with the second photodector channel is registered.
  • another object of the present invention are oligonucleotide primer pairs for the duplication of 16S rRNA fragments from extracted bacterial DNA for the specific detection of mycobacteria and for the differentiation of the Mycobacterium tuberculosis complex and Mycobacterium avium from other types of mycobacteria in clinical material, whereby a A pair of primers comprising nucleotide sequences SEQ ID NO: 2 / SEQ ID NO: 3 or a pair of degenerate or mutated nucleotide sequences or fragments thereof.
  • degenerate or mutated nucleotide sequences have the property of hybridizing in each case with the sequences SEQ ID NO: 2 / SEQ ID NO: 3, with a degree of homology of at least 90%, preferably at least 95%, particularly preferably at least 98%. , is preferred.
  • the invention also relates to a second pair of primers with a primer with the nucleotide sequence SEQ ID NO: 4 or a degenerate or mutated nucleotide sequence or a fragment thereof which hybridizes with the sequence SEQ ID NO: 4, a degree of homology of at least 90%, preferably of at least 95%, particularly preferably at least 98% is preferred.
  • another object of the present invention are oligonucleotide hybridization probe pairs for the specific detection of mycobacteria and for differentiating the Mycobacterium tuberculosis complex and Mycobacterium avium from other mycobacterial species in clinical material, selected from the group consisting of the nucleotide sequences SEQ ID NO: 10 / SEQ ID NO: 11 or the pair of complementary sequences thereof, the nucleotide sequences SEQ ID NO: 6 / SEQ ID NO: 7 or the pair of complementary sequences thereof and the nucleotide sequences SEQ ID NO: 8 / SEQ ID NO: 9 or the pair of complementary sequences thereof.
  • another object of the present invention is an artificial plasmid, control plasmid, preferably obtained by subcloning the 16S rRNA gene in pGEM-T, which acts as an internal control of the amplification (inhibition control) and the specific detection of 16S -rRNA fragments of mycobacteria and contains a nucleic acid sequence of the modified genus-specific region III of the 16S rRNA gene.
  • the control plasmid according to the invention is preferably by nucleotide exchange, nucleotide addition, nucleotide deletion and / or nucleotide inversion of at least one nucleotide, preferably two nucleotides, of the wild-type nucleic acid sequence of the genus-specific region III of the 16S rRNA. Gene derived.
  • the artificial plasmid comprises the nucleotide sequence SEQ ID NO: 14 or SEQ ID NO: 15, in each case one nucleotide compared to the wild-type sequence is exchanged. Particularly surprisingly, it was found that the replacement of the one nucleotide resulted in a reduction in the melting temperature of the genus-specific hybridization probes of approximately 1 ° C.
  • the artificial plasmid comprises the nucleotide sequence SEQ ID NO: 16 or SEQ ID NO: 17, in each of which two nucleotides are exchanged for the wild-type sequence.
  • the replacement of the two nucleotides leads to a reduction in the melting temperature of the genus-specific hybridization probes of approximately 14.5 ° C.
  • the present invention furthermore relates to a diagnostic kit for the specific detection of a mycobacterial infection and of M. tuberculosis and M. avium in clinical material according to the methods according to the invention, the at least one polymerase, at least one, preferably all of the aforementioned primer pairs and comprises at least one, preferably all, of the aforementioned hybridization probe pairs.
  • the diagnostic kit preferably additionally comprises at least one artificial control plasmid according to the invention as an internal standard.
  • SEQ ID NO: 2 "sense" primer ("forward" primer) of the primer pair for the amplification of a 300 bp fragment of the 16S rRNA gene of mycobacteria, containing the species-specific regions of the M. tuberculosis complex and by M. avium,
  • SEQ ID NO: 3 "antisense” primer ("reverse” primer) of the primer pair for the amplification of a 300 bp fragment of the 16S rRNA gene from mycobacteria, containing the species-specific regions of the M. tuberculosis complex and by M. avium,
  • SEQ ID NO: 4 "sense" primer ("forward” primer) 'of the primer pair for the amplification of a 100 bp fragment of the 16S rRNA gene of mycobacteria, containing the genus-specific region III of the genus Mycobacterium,
  • SEQ ID NO: 5 "antisense” primer ("reverse” primer) a) of the primer pair for the amplification of a 1000 bp fragment of the 16S rRNA gene from the mycobacteria, containing the species-specific regions of the M. tuberculosis Complex and of M.
  • SEQ ID NO: 7 "sense" hybridization probe, in particular acceptor component, of the probe pair for the detection of the species-specific region of the M. tuberculosis complex
  • SEQ ID NO: 8 "antisense" hybridization probe, in particular donor component, of the probe pair for detection of the species-specific region of M. avium,
  • SEQ ID NO: 9 “sense” hybridization probe, in particular acceptor component, of the probe pair for detecting the species-specific region of M. avi um, ⁇
  • SEQ ID NO: 10 "antisense" hybridization probe, in particular donor component, of the probe pair for the detection of the genus-specific region III of the genus Mycobacterium,
  • SEQ ID NO: 11 "sense" hybridization probe, in particular acceptor component, of the probe pair for the detection of the genus-specific region III of the genus Mycobacterium,
  • SEQ ID NO: 14 modified "sense" primer ("forward" primer) for the amplification of a complete control plasmid, containing a modified genus-specific region III of the 16S rRNA gene of mycobacteria,
  • SEQ ID NO: 15 modified "antisense” primer ("reverse” primer) for the amplification of a complete control plasmid, containing a modified genus-specific region III of the 16S rRNA gene of mycobacteria,
  • SEQ ID NO: 17 modified "antisense" primer ("reverse” primer) for the amplification of a further complete control plasmid, containing a further modified genus-specific region III of the 16S rRNA gene of mycobacteria.
  • FIG. 1 Schematic representation of the 16S rRNA gene of mycobacteria (length: 1523 bp), the position of the species-specific regions, "species (A)” and “species (B)", and the genus-specific regions “genus I”, “genus II” and “genus III”, and the location and size of the means the
  • Primer pairs (1) and (5), (2) and (3) and (4) and (5) amplified fragments.
  • Figure 3 Modified 16S rRNA fragment as an internal standard (pJL6): melting curves of the hybridization of the genus-specific hybridization probes with the genus-specific region III and the modified genus-specific region III of the internal standard (pJL6) with a different number of genomes - pien of the genus-specific region III.
  • Figure 4 Modified 16S rRNA fragment as an internal standard (pJL6): melting curves of the hybridization of the genus-specific hybridization probes with the genus-specific region III and the modified genus-specific region III of the internal standard (pJL6) in the presence of different amounts of "background" DNA from E. coli.
  • Microbial DNA is purified from clinical samples consisting of sputum, bronchial lavage, gastric juice, urine, stool, cerebrospinal fluid, bone marrow, blood or punctate biopsies in a manner known per se, for example using a Qiamp TM MiniKit (company Qiagen, catalog No. 51306) , that is extracted. Chromosomal DNA is quantified using the PicoGreen TM system (Molecular Probes).
  • Microbial DNA of different cultures of microorganisms is isolated in particular for evaluating the detection methods according to the invention.
  • microbial DNA is isolated from these cultures.
  • the microbial DNA is then purified in a manner known per se, for example using a Qiamp TM MiniKit (company Qiagen, catalog no. 51306), that is to say extracted.
  • Chromosomal DNA is quantified in a manner known per se, for example using the PicoGreen TM system (Molecular Probes).
  • the primer pair a) SEQ ID NO: 1 / SEQ ID NO: 5 is used for the amplification, which amplifies a 1000 bp fragment of the 16S rRNA containing the genus-specific region III and the species-specific regions.
  • the two primer pairs b) are used simultaneously in a multiplex PCR batch, in parallel batches or at different times, the primer pair containing SEQ ID NO: 2 / SEQ ID NO: 3 being 300 bp long Fragment of the 16S rRNA containing the species-specific regions, amplified and used for the subsequent detection of the M. tuberculosis complex and / or M. avium, and wherein the primer pair containing SEQ ID NO: 4 / SEQ ID NO: 5 a 100 bp fragment of the 16S rRNA containing the genus-specific region III, amplified and used for the subsequent detection of a mycobacterial infection.
  • the pair of probes c) SEQ ID NO: 10 / SEQ ID NO: 11 or a complementary or mutated or degenerate pair thereof is used for the detection of the genus-specific region III. If the M. tuberculosis complex is only to be detected in the method according to the invention in addition to the genus-specific detection, the pair of probes d) SEQ ID NO: 6 / SEQ ID NO: 7 or their equivalents, ie mutated or complementary pairs thereof, are used. On the other hand, if only mycobacteria of the type M.
  • the probe pair e) SEQ ID NO: 8 / SEQ ID NO: 9 or their equivalents, ie mutated or complementary pairs thereof, are used. If both the M. tuberculosis complex and M. avium are to be detected together with the genus-specific region III, both probe pairs d) and e) are used in addition to the probe pair c).
  • This reaction mixture is brought into the glass capillaries of the LightCycler TM system by pulse centrifugation and the amplification according to the "hot start" principle is carried out after an initial denaturation at 95 ° C. for 10 minutes with the following steps: 1. Denaturation at 95 C for 3 seconds
  • Steps 1 to 3 are carried out cyclically a total of 50 times, with the hybridization in step 2 taking place at 68 ° C. for the first 5 cycles and the temperature being reduced to 62 ° C. in steps of 1 ° C. per cycle in the subsequent 6 cycles and is carried out at 62 ° C for the remaining cycles.
  • the rate of temperature change in all steps is 20 ° C per second.
  • the FRET-labeled hybridization probe pairs used in the reaction mixture are used to detect the amplified fragments, one hybridization probe partner in each case
  • SEQ ID NO: 10 SEQ ID NO: 6 or SEQ ID NO: 8
  • SEQ ID NO: 11 SEQ ID NO: 7 or SEQ ID NO: 9
  • LightCycler TM -Green 640 is associated with LightCycler TM -Green 640 as acceptor component on the 5 'terminal nucleotide.
  • the melting curve analysis carried out in the course of the detection begins with the denaturation of the amplified fragments at 95 ° C. for 30 seconds, followed by hybridization with the aforementioned FRET pairs at 38 ° C. for 30 seconds. To determine Following the melting curve of the hybridization, the temperature is then continuously increased from 38 ° C. to 80 ° C. at a rate of 0.2 ° C./sec, the fluorescence emitted by the FRET pairs being continuously recorded. Version 3.5.3 of the LightCycler "Run Profile" program is used to evaluate the fluorescence signal, with the gain of the F2 channel of the photometric detector of the LightCycler TM system being set automatically.
  • the entire 16S rRNA gene of mycobacteria (1523 bp) is first included amplified a pair of PCR primers, the “sense” primer consisting of the nucleotide sequence SEQ ID NO: 12 and the “antisense” primer consisting of the nucleotide sequence SEQ ID NO: 13.
  • the “sense” primer consisting of the nucleotide sequence SEQ ID NO: 12
  • the “antisense” primer consisting of the nucleotide sequence SEQ ID NO: 13.
  • the genus-specific region III of the 16S rRNA contained in the artificial plasmid should differ from the wild-type nucleotide sequence of the genus-specific region III by at least one point mutation.
  • modified primer pairs are used for the multiplication of the plasmids containing the subcloned fragments, in which one or two nucleotides in the nucleotide sequences were exchanged for the wild-type nucleotide sequences ,
  • primer pairs derived from the wild-type sequence of the genus-specific region III, in particular from the region binding the acceptor component of the FRET pair according to the invention, SEQ ID NO: 11, are used for this purpose: a) Exchange of a nucleotide:
  • nucleotide sequences according to the invention of the aforementioned modified primer pairs the underlined nucleotide was replaced in each case by the wild-type sequence of the genus-specific region III.
  • control plasmids with the modified primer pairs is in each case in a "long range” PCR with a Pfu polymerase, type: "Pfu Turbo Hot Start DNA” (Stratagene) in a manner known per se in a "hot start” PCR procedure carried out with 18 cycles of the following steps:
  • Results a) The amplicons obtained are additionally purified using a gel and the point mutations can then be confirmed by sequencing.
  • a control plasmid is obtained by using the primers SEQ ID NO: 16 and SEQ ID NO: 17 according to the invention which contains a 16S rRNA fragment modified by exchanging two nucleotides. 50 copies of the control plasmid are mixed as an internal standard with different numbers of gene copies of the 16S rRNA gene from M. tuberculosis and subjected to the detection method according to Example 1. Result :
  • This internal standard can therefore also be used if • it can be expected that the number of gene copies to be detected in the clinical material will be an order of magnitude less than the number of plasmid copies used as the internal standard.
  • a control plasmid (which contains a 16S rRNA fragment modified by exchanging two nucleotides) is obtained by using the primers SEQ ID NO: 16 and SEQ ID NO: 17 according to the invention. 50 copies of the control plasmid and 10 gene copies of the 16S rRNA gene from M. tuberculosis are mixed with different amounts of "background" DNA from E. coli in the range from 1 pg to 200 ng and then according to the detection method Example 1 subjected. Result :
  • the detection method according to the invention in particular using this internal standard, is thus also possible if it can be expected that a large amount of foreign DNA, “background” DNA, is present in the isolated clinical material.
  • Example 3 Assessment of the performance of the detection method according to the invention on the LightCycler TM system
  • genomic DNA of the bacterial strain Mycobacterium bovis BCG of the M. tuberculosis complex is used as a “template”.
  • Example 4 Specific amplification of 16S rRNA fragments from mycobacteria (according to the invention)
  • Example 1 In a first approach according to Example 1, a 100 bp fragment of the genus-specific region III (SEQ ID NO: 4 / SEQ ID NO: 5) and a 300 bp fragment of the species-specific regions (SEQ ID NO: 2 / SEQ ID NO: 3) amplified. In a second approach according to Example 1, a 1000 bp long fragment, which contains both the genus-specific region III and the two species-specific regions, is amplified with the corresponding primer pair (SEQ ID NO: 1 / SEQ ID NO: 5).
  • the 1000 bp fragment amplified with the primer pair SEQ ID NO: 1 / SEQ ID NO: 5 is used in the detection method according to the invention (Example 1).
  • a dilution series of the M. avium genome is prepared and a melting curve analysis of the amplified fragments is carried out with the corresponding hybridization probe pairs.
  • a 1000 bp fragment of the 16S rRNA gene is amplified with the genus-specific primer pair SEQ ID NO: 1 / SEQ ID NO: 5.
  • a melting curve analysis of the amplified fragments using the hybridization probe pair SEQ ID NO: 10 / SEQ ID NO: 11, specific for the genus-specific region III, is carried out.
  • the melting point of amplified 16S rRNA fragments of the genus Corynebacterium is 43 ° C, or no hybridization signal can be detected at all.
  • genomic DNA from the microorganisms listed in Table 1 are first used, and each 1000 bp fragment is amplified.
  • a melting curve analysis of the amplicons is then carried out using the species-specific hybridization probe pair SEQ ID NO: 6 / SEQ ID NO: 7.
  • the melting temperature for the types of the M. tuberculosis complex is a uniform 64 ° C
  • the melting temperature for all non-tuberculous pathogens is between 43.5 ° C and 54 ° C, if a hybridization signal can be detected at all (Table 1) ,
  • tubercular pathogens can be selectively detected compared to all other non-tubercular pathogens.
  • genomic DNA of the microorganisms listed in Table 1 are used first and a 1000 bp long fragment is amplified in each case.
  • a melting curve analysis of the amplicons is then carried out using the species-specific hybridization probe pair SEQ ID NO: 8 / SEQ ID NO: 9. Result :
  • the melting temperature for M. avium is a uniform 61 ° C
  • the melting temperature for all other pathogens is between 43 ° C and 54 ° C, if a hybridization signal can be detected at all (Table 1).
  • the non-tuberculous M. avium pathogen can be selectively detected compared to all other pathogens.
  • Example 7 Comparative example for the specificity of the genus-specific detection by means of the genus-specific region II ("genus II")
  • Example 8 Quantitative determination of the mycobacterial content in clinical samples (according to the invention)
  • the degree of fluorescence in this wavelength range is a function of the amount of DNA present and detected in the sample under certain conditions.
  • the FRET system enables quantitative measurements of the amount of amplified DNA fragments if the selected hybridization probes bind quantitatively, ie stoichiometrically, to the amplified fragments.
  • the standard is measured separately from the samples to be examined, using at least five different concentrations to create a standard curve. If the plasmid pIJ6 is used, a concentration of the standard can be used in each sample examined.
  • the distinction between standard and "target DNA" is based on the different melting point.
  • the standard serves in particular as a control that the amplification was not inhibited by interference factors (inhibition control).
  • the FRET-labeled hybridization probe pairs used in the reaction mixture are used to detect the amplified fragments.
  • the amplification reaction proceeds as in Example 1, with the fluorescence being measured after each amplification step.
  • the optimal annealing temperature is 62 ° C.
  • the melting point analysis is carried out unaffected after completion of the amplification reaction as in Example 1 c). Table 1:

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Abstract

La présente invention concerne un procédé de biologie moléculaire permettant de détecter de manière spécifique les mycobactéries et de différencier la mycobactérie du complexe tuberculosis et la mycobactérie avium d'autres mycobactéries dans un matériau clinique à l'aide d'amorces d'amplification et de sondes oligonucléotidiques qui sont spécifiques aux régions spécifiques au genre et à l'espèce du gène 16S-ARNr de mycobactéries.
EP03729922A 2002-04-06 2003-04-04 Detection de mycobacteries dans des materiaux cliniques Withdrawn EP1495143A1 (fr)

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DE10215238A DE10215238C1 (de) 2002-04-06 2002-04-06 Nachweis von Mykobakterien in klinischem Material
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PCT/EP2003/003533 WO2003085129A1 (fr) 2002-04-06 2003-04-04 Detection de mycobacteries dans des materiaux cliniques

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WO2006108205A2 (fr) * 2005-04-15 2006-10-19 Thomas Schlederer Procede de detection de fragments d'acide nucleique
ATE522608T1 (de) * 2006-12-18 2011-09-15 Wako Pure Chem Ind Ltd Primer und sonde zum nachweis von mycobacterium avium sowie verfahren zum nachweis von mycobacterium avium unter verwendung des primers bzw. der sonde
KR101413659B1 (ko) * 2007-12-06 2014-07-01 삼성전자주식회사 실시간 핵산 증폭 데이터로부터 시료 중의 표적 핵산의초기 농도를 결정하는 방법
WO2010071147A1 (fr) * 2008-12-16 2010-06-24 アークレイ株式会社 Procédé de détection de régulations de l'amplification d'acide nucléique et utilisation associée
WO2010111509A1 (fr) * 2009-03-25 2010-09-30 Life Technologies Corporation Adn témoin de discrimination positive/d'extraction
CN103451313B (zh) * 2013-09-27 2016-03-09 中国科学院上海微系统与信息技术研究所 一种基因芯片的金沉积检测方法
EP3680348B1 (fr) 2014-02-07 2023-04-12 University of Iowa Research Foundation Sondes à base d'oligonucléotides et procédés de détection de microbes
CN112538539B (zh) * 2020-11-26 2022-09-23 中国医学科学院北京协和医院 用于鸟分枝杆菌检测的试剂盒及系统

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ES2140400T3 (es) * 1991-08-15 2000-03-01 Hoffmann La Roche Cebadores y sondas del micobacterium.
WO1993022461A1 (fr) * 1992-05-06 1993-11-11 Gen-Probe Incorporated Procede, composition et kit pour l'amplification de sequences d'acides nucleiques
US6136529A (en) * 1993-09-03 2000-10-24 Gen-Probe Incorporated Nucleic acid probes to Mycobacterium avium complex
WO1995031571A2 (fr) * 1994-05-13 1995-11-23 Abbott Laboratories Materiaux et procedes de detection de microbacteries
US6140054A (en) * 1998-09-30 2000-10-31 University Of Utah Research Foundation Multiplex genotyping using fluorescent hybridization probes
EP1307587A2 (fr) * 2000-03-03 2003-05-07 THE GOVERNMENT OF THE UNITED STATES OF AMERICA, as represented by THE SECRETARY, DEPARTMENT OF HEALTH AND HUMAN SERVICES SYSTEME D'HYBRIDATION MULTIPLEX DESTINE A L'IDENTIFICATION DE i MYCOBACTERIUM /i PATHOGENE ET PROCEDE D'UTILISATION
KR100433260B1 (ko) * 2000-09-15 2004-05-24 주식회사 에스제이하이테크 멀티플렉스 ｐｃｒ 방법 및 이를 이용한 마이코박테리아동정용 키트 및 올리고 뉴클레오티드

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US20060088833A1 (en) 2006-04-27
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WO2003085129A8 (fr) 2003-12-31
AU2003240448A1 (en) 2003-10-20

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