KR20190078555A - Genetic Marker for Discrimination and Detection of Vibriosis in fish and Method for Discrimination and Detection of Vibriosis in fish Using the Same - Google Patents

Abstract

The present invention relates to a genetic marker for identifying and detecting vibrio infectious diseases, and a method for identifying and detecting bacterial pathogens using the same, and more specifically, to a method which selects a DNA base sequence coding a specific gene of bacterial pathogen of fish vibrio infectious diseases to amplify the same, hybrids peptide nucleic acids (PNA) specifically recognizing the amplified product, obtains a melting curve for each temperature through a temperature regulation of hybridized product, and identifies vibrio infectious diseases or detects whether fish is infected by vibrio infectious diseases from the melting temperature through the analysis of the obtained melting curve. The present invention enables an accurate diagnosis within few hours to reduce economic loss through the accurate and rapid diagnosis of vibrio infectious diseases frequently occurring in flatfish in a fish farm. In addition, through accurate identification and early diagnosis for the proper use of antibiotic, it is possible to prevent antibiotics from being overused or misused and unnecessary manufacturing costs from increasing.

Description

Genetic Marker for Discrimination and Detection of Vibriosis in Fish and Method for Discrimination and Detection of Vibriosis in Fish Using the Same}

The present invention relates to a genetic marker for discrimination and detection of Vibrio infectious disease, and a method for discriminating and detecting the causative bacteria using the same, and more particularly, a DNA sequence encoding a specific gene of the causative organism of fish Vibrio infectious disease is selected and amplified. , Peptide Nucleic Acid (PNA), which specifically recognizes the amplified product, is hybridized, and the melting curve for each temperature is obtained through temperature control of the hybridized product, and Vibrio infection is obtained from the melting temperature through the analysis of the obtained melting curve. It relates to a method of determining whether or not a fish is infected with Vibrio infection.

Fish vibrio infection, fish streptococcal infection, and fish Edward infection are infected with flounder, tilapia, yellowtail, and rainbow trout, which are widely cultivated around the world, causing high mortality. In particular, flounder, which is the most produced among domestic farmed fish species, accounts for about 50% of the total production of farmed fish, but its damage is increasing due to the occurrence of infectious diseases caused by pathogens such as parasites, bacteria, and viruses. In particular, in the disease survey conducted on farmed flounder, the detection rates of parasites, bacteria, and viruses in farmed flounder were 43.2%, 38.8%, and 24.4%, respectively, and it was reported that the bacteria of the genus Vibrio were the most among the detected fish disease bacteria, 9.7%. Therefore, it is the time when infectious and pathogenic discrimination is becoming important.

Various methods have been developed to analyze bacterial genes, and gene sequencing (sanger sequencing), random amplified polymorphic DNA (RAPD), and restriction fragment length polymorphism (RFLP) methods have been used, but the analysis time is still long and the procedure. It has a problem of being tricky. The detection of bacterial diseases used in the aquaculture field relies on a bacterial culture method that requires a lot of time, and such a bacterial culture method has low objectivity and there is a possibility of detection error, and the bacterial culture method using a selective medium can only test for a single bacteria. It has a disadvantage that detailed classification is impossible. Biochemical analysis (API test) is used to increase the accuracy of detection, but rapid detection is impossible due to the complicated procedure and long reaction time. In particular, in the case of aquatic disease-related bacteria, the accuracy is low because there are not many databases. Not being used. By overcoming these problems and developing a molecular detection product that can accurately detect within a few hours, the damage of bacterial diseases can be prevented early.

Thus, there is a need for a method of selecting a genotype and a genomic marker of pathogenic bacteria detected in infected fish, and using the marker to easily analyze the pathogenicity of bacteria according to the genotype. The development of such markers accurately detects and discriminates the causative bacteria of Vibrio infection that frequently occurs in fish such as farmed flounder, and through early detection of individuals infected with the causative bacteria, accurate identification of the causative bacteria and misuse of antibiotics in fish and unnecessary It can prevent the increase in the production cost of fish.

Accordingly, the present inventors have tried to determine the species of the vibrio infectious disease causative bacteria and to develop a method for detecting an individual infected with the causative bacteria, as a result of which, as a result, Vibrio harvey , Vibrio scophthalmi , which are the causative bacteria of Vibrio infectious disease. , Vibrio yichyo Lee Enterprise (Vibrio ichtyoenteri ), Vibrio fischeri , Vibrio alginorithicus ( Vibio alginolyticus ), Vibrio eyelarium (Vibrio anguillarium ), Vibrio splendidus , and Photobacterium damselae (Photobacterium damselae) to discover a genetic marker for discrimination and/or detection, and by using a peptide nucleic acid and a primer pair specific to the gene marker By showing different fluorescence amplification and melting curves for each, it was confirmed that there is an effect of simply, quickly, and accurately discriminating the bacteria that cause fish diseases, and the present invention was completed.

It is an object of the present invention to identify Vibrio bacteria including primers and probes capable of detecting a specific nucleotide sequence (SEQ ID NO: 18 to SEQ ID NO: 26) of 8 kinds of Vibrio infection causative bacteria for accurate and rapid diagnosis of Vibrio infection or It is to provide a composition for detection.

In order to achieve the above object, the present invention is represented by the nucleotide sequence of SEQ ID NO: 18 to 26 including single nucleotide polymorphism (SNP) among the DNA nucleotide sequences encoding the 16S rDNA or dnaJ gene of Vibrio bacteria. It is possible to provide a composition for discrimination or detection of Vibrio bacteria comprising a primer and a probe capable of detecting one or more genes among the genes.

The present invention can also provide a primer pair for discrimination or detection of Vibrio bacteria represented by the nucleotide sequences of SEQ ID NOs: 1 and 2, SEQ ID NOs: 3 and 4, SEQ ID NOs: 5 and 6, or SEQ ID NOs: 7 and 8.

The present invention can also provide a PNA probe for discrimination or detection of Vibrio bacteria represented by one or more nucleotide sequences of SEQ ID NOs: 9 to 17.

The present invention also includes the steps of: (a) extracting a target nucleic acid from a specimen; (B) amplifying and hybridizing a gene of Vibrio contained in the target nucleic acid using a primer and a probe capable of detecting one or more genes among the genes represented by the nucleotide sequence of SEQ ID NO: 18 to SEQ ID NO: 26; (c) obtaining a melting curve for each temperature while increasing the temperature of the product hybridized in step (b); And (d) detecting Vibrio bacteria from the melting temperature through analysis of the melting curve obtained in step (c), or Alternatively, it is possible to provide a method for discriminating or detecting Vibrio bacteria comprising the step of determining whether or not the bacterial species are infected with fish.

The present invention enables accurate diagnosis within several hours, thereby reducing economic loss through accurate and rapid diagnosis of Vibrio infection that frequently occurs in farmed flounder, and misuse of antibiotics through the use of appropriate antibiotics through accurate identification and early diagnosis. And it can prevent unnecessary increase in production cost.

1 is Vibrio , Photobacterium It shows the 16S rDNA gene specific nucleotide sequence for identification and detection of the genus of Vibrionaceae, including.
Figure 2 is anguilarium V., V. alginolyticus And 16S rDNA gene specific nucleotide sequence for discrimination and detection of P. damselae.
Figure 3 shows the 16S rDNA gene-specific nucleotide sequence for discrimination and detection of V. splendidus.
Figure 4 shows the 16S rDNA gene gene specific nucleotide sequence for discrimination and detection of V. fischeri.
Figure 5 shows the 16S rDNA gene gene specific nucleotide sequence for discrimination and detection of V. ichtyoenteri and V. scophthalmi.
6 is a nucleotide sequence diagram of a gene-specific peptide nucleic acid for discrimination and detection of V. ichtyoenteri using a dnaJ gene.
7 shows V. alginolyticus , P. anguillarium , V. splendidus , V. fischeri and P. damselae The Tm parameters of the PNA probe for discrimination and the probe for discrimination in the genus Vibrionaceae were analyzed.
8 is V. harvey, V. ichtyoenteri , V. scophthalmi This is an analysis of the Tm parameter of the PNA probe for discrimination.
9 to 10 are analysis of the binding temperatures of PNA probes corresponding to A SET, B SET, and C SET, respectively.
Figure 11 is to prepare a forward primer corresponding to A SET. The nucleotide sequence of the selected primer site is indicated in yellow.
Figure 12 is to prepare a forward primer corresponding to the B SET. The nucleotide sequence of the selected primer site is indicated in yellow.
13 shows a forward primer corresponding to C SET was prepared. The nucleotide sequence of the selected primer site is indicated in yellow.
14 shows a reverse primer corresponding to C SET was prepared. The nucleotide sequence of the selected primer site is indicated in yellow.
15 is a schematic diagram showing the principle of multi-analysis real-time PCR of a PNA fluorescent probe.
16 shows the configuration of PCR for diagnosis of Vibrio infection.
Figure 17 shows the reaction conditions of real-time PCR (Real-Time Polymerase Chain Reaction) for discrimination of bacterial species causing Vibrio infection and detection of bacterial infection of an individual.
18 shows the results of Singleplex PCR for diagnosis/discrimination in Vibrionaceae genus of A SET using 8 types of bacteria of Vibrio and Photobacterium.
19 shows the results of Singleplex PCR of B SET. (A) V. harvey, (B) V. ichtyoenteri . V. scophthalmi , (C) shows the results of dnaJ , V. ichtyoenteri, (D) shows the results of P. damselae.
20 shows the results of Singleplex PCR of C SET. (A) shows the results of V. fischeri , (B) V. alginolyticus , (C) V. anguillarium , and (D) V. splendidus .
Figure 21 shows the results of multiple analysis PCR of B SET and C SET.
22 to 23 show kit sensitivity analysis for DNA of Vibrio bacteria using a multiple assay kit. Fig. 22 shows the results in B SET, and Fig. 23 shows the results in C CET. Figure 22 shows (A) V. harvey , (B) V. scophthalmi , (C) V. ichtyoenteri , (D) P. damselae , and Figure 23 (A) V. alginolyticus , (B) V. fischeri , (C) ) V. anguillarium , (D) V. splendidus Represents.
24 shows a schematic diagram of a detection ability test in a mixed situation with flounder DNA.
25 is an analysis of the specificity and sensitivity of real-time PCR based on a PNA probe.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by an expert skilled in the art to which the present invention belongs. In general, the nomenclature used in this specification and the experimental methods described below are well known and commonly used in the art.

The present invention discriminates the species of bacteria that cause Vibrio infectious disease, and as a result of trying to develop a method for detecting an individual infected with the causative bacteria, Vibrio Viride Vibrio Harvey (V. harvey ), Vibrio scophthalmi (V. scophthalmi), Vibrio Icho entertainment ( V. ichtyoenteri ), photobacterium damselae (P. damselae ), Genetic markers for discrimination and/or detection of V. fischeri , V. alginolyticus , V. anguillarium , and V. splendidus were discovered. And, by using a pair of peptide nucleic acids and primers specific to the gene marker to show different fluorescence amplification and melting curves for each bacterial species, it was to be confirmed that there is an effect that can easily, quickly and accurately discriminate the bacteria that cause fish diseases. I did.

Bacteria belonging to the Vibrio (Vibrionaceae) is Vibrio sp . Aeromonas sp . Plesiomonas sp . Photobacterium sp . Lucibacterium sp . In the present invention, Vibrio harvey (V. harvey ), Vibrio scophthalmi (V. scophthalmi), Vibrio ichyoenteri (V. ichtyoenteri), and photobacterium damsela (P. damselae), which are bacteria of the family Vibrio that cause infection in fish ), Vibrio pischeri (V. fischeri), Vibrio alginoriticus (V. alginolyticus), Vibrio anguillarium (V. anguillarium) and Vibrio splendidus (V. splendidus ) detection methods were developed.

In one embodiment of the present invention, in order to develop a method for determining bacterial species with a genetic marker for discrimination and detection of the bacteria causing Vibrio infectious disease, and for detecting whether the bacterial species of fish is infected, 16S rDNA or dna J of the bacteria The nucleotide sequence was secured, and a representative sequence was prepared for each bacterial species with CLC Genomic workbench 8.0.1, and then the genes were compared and analyzed by clustal W alignment. Vibrio harvey (V. harvey ), Vibrio scophthalmi (V. scophthalmi), Vibrio ichtyoenteri (V. ichtyoenteri), photobacterium damselae (P. damselae), and Vibrio pischeri (V. fischeri ), Vibrio alginorilyticus (V. alginolyticus), Vibrio anguillarium (V. anguillarium) and Vibrio splendidus (Single nucleotide) of the DNA sequences encoding the 16S rDNA gene. A genetic marker (site) including polymorphism, SNP) was selected as a target, and the species of the vibrio infectious disease-causing bacteria could be detected and discriminated using a primer pair for determining bacterial species corresponding to the genetic marker and a PNA probe.

Accordingly, the present invention is, in one aspect, of the genes represented by the nucleotide sequences of SEQ ID NOs: 18 to 26 including single nucleotide polymorphism (SNP) among the DNA nucleotide sequences encoding the 16S rDNA or dnaJ gene of Vibrio It relates to a composition for discrimination or detection of Vibrio bacteria comprising a primer and a probe capable of detecting one or more genes.

The primers of the present invention may be selected from primer pairs represented by the nucleotide sequences of SEQ ID NOs: 1 and 2, SEQ ID NOs: 3 and 4, SEQ ID NOs: 5 and 6, or SEQ ID NOs: 7 and 8.

The probe of the present invention may be characterized in that it is represented by one or more nucleotide sequences of SEQ ID NO: 9 to SEQ ID NO: 17.

In another aspect, the present invention is the identification or detection of a primer pair for identification or detection of Vibrio bacteria represented by the nucleotide sequences of SEQ ID NOs: 1 and 2, SEQ ID NOs: 3 and 4, SEQ ID NOs: 5 and 6, or SEQ ID NOs: It relates to a pair of primers.

In another aspect, the present invention is represented by one or more nucleotide sequences of SEQ ID NOs: 9 to 17 corresponding to single nucleotide polymorphism (SNP) in the DNA nucleotide sequence encoding the 16S rDNA or dnaJ gene of Vibrio bacteria. It relates to a PNA probe for discrimination or detection of a probe for discrimination or detection of Vibrio bacteria.

In the present invention, the Vibrio bacteria are Vibrio harvey (V. harvey ), Vibrio scophthalmi (V. scophthalmi), Vibrio ichyoenteri (V. ichtyoenteri), photobacterium damselae (P. damselae), Vibrio pischeri ( V. fischeri ), Vibrio alginoriticus (V. alginolyticus), Vibrio anguillarium (V. anguillarium) and Vibrio splendidus (V. splendidus ) It may be selected from the group consisting of.

In the PNA probe of the present invention, a reporter and a fluorescent material of a quencher capable of quenching reporter fluorescence may be combined at both ends.

The reporter is FAM (6-carboxyfluorescein), Texas red, HEX (2',4',5',7',-tetrachloro-6-carboxy-4,7-dichlorofluorescein), Quasar, JOE, Cy3 and It may be one or more selected from the group consisting of Cy5, and the quencher may be one or more selected from the group consisting of 6-carboxytetramethyl-rhodamine (TAMRA), BHQ1, BHQ2, and Dabcyl, but is not limited thereto, and preferably Dabcyl (FAM-labeled) can be used.

Peptide nucleic acid (PNA) is a similar DNA in which a nucleic acid base is linked by a peptide bond rather than a phosphate bond, and was first synthesized by Nielsen et al. in 1991. PNA is not found in nature and is artificially synthesized by chemical methods.

Peptide nucleic acid is artificially synthesized as one of gene recognition materials such as LNA (Locked Nucleic Acid) or MNA (Mopholino nucleic acid), and its basic skeleton is composed of polyamide. PNA has excellent affinity and selectivity, and has high stability against nucleases, so it is not degraded by existing restriction enzymes. In addition, thermal/chemical properties and stability are high, so storage is easy and it is not easily decomposed.

PNA forms double strands through a hybridization reaction with a natural nucleic acid having a complementary nucleotide sequence. When the length is the same, the PNA/DNA double strand is more stable than the DNA/DNA double strand, and the PNA/RNA double strand is more stable than the DNA/RNA double strand. In addition, PNA is more capable of detecting single nucleotide polymorphism (SNP) than natural nucleic acids because the degree of double-strand instability is large due to single base mismatch.

In addition, PNA-DNA binding power is very superior to DNA-DNA binding power, so even a nucleotide miss match differs by about 10 to 15°C. Using this difference in avidity, it is possible to detect changes in SNP (Single-nucleotide polymorphism) and In/Del nucleotides.

The length of the PNA nucleotide sequence according to the present invention is not particularly limited, but may be prepared in a length of 12 to 18 mer so that the SNPs of bacterial species are included. At this time, it is possible to design a PNA probe to have a desired Tm value by adjusting the length of the PNA probe, or it is also possible to adjust the Tm value by changing the base sequence even with a PNA probe of the same length. In addition, since PNA probes have better binding power than DNA and have a high basic Tm value, they can be designed to have a shorter length than DNA, so that even close neighboring SNPs can be detected. According to the existing HRM (High Resolution Melt) method, the difference in Tm value is very small, about 0.5℃, requiring additional analysis program or detailed temperature change or correction. For this reason, analysis was difficult when two or more SNPs appeared. , The PNA probe according to the present invention is not affected by the sequence and SNP of the PNA probe, and thus can be conveniently analyzed.

The composition of the present invention may optionally contain a buffer, a DNA polymerase cofactor, and reagents necessary for carrying out a target nucleic acid amplification reaction (eg, PCR reaction) such as deoxyribonucleotide-5-triphosphate. Optionally, the compositions of the present invention may also contain various polynucleotide molecules, reverse transcriptases, various buffers and reagents, and antibodies that inhibit DNA polymerase activity. In addition, the optimum amount of the reagent to be used in a particular reaction in the composition can be easily determined by a person skilled in the art who has learned the disclosure herein. Typically, the compositions of the present invention may be made in separate packaging or compartments containing the aforementioned constituents.

Using the composition, it is possible to effectively detect a single base mutation of a target nucleic acid and a mutation due to a deletion or insertion of a base through the analysis of a dissolution curve by a PNA probe, and through this, it is possible to discriminate a bacterial species.

In another aspect of the present invention, (a) extracting a target nucleic acid from a sample sample; (b) amplifying and hybridizing a gene of Vibrio contained in the target nucleic acid using primers and probes capable of detecting one or more genes among the genes represented by the nucleotide sequences of SEQ ID NO: 18 to SEQ ID NO: 26; (c) obtaining a melting curve for each temperature while increasing the temperature of the product hybridized in step (b); And (d) detecting Vibrio from the melting temperature through analysis of the melting curve obtained in step (c), or determining whether the bacterial species is infected with fish. will be.

In the present invention, the Vibrio bacteria are Vibrio harvey (V. harvey ), Vibrio scophthalmi (V. scophthalmi), Vibrio ichyoenteri (V. ichtyoenteri), photobacterium damselae (P. damselae), Vibrio pischeri ( V. fischeri ), Vibrio alginoriticus (V. alginolyticus), Vibrio anguillarium (V. anguillarium) and Vibrio splendidus (V. splendidus ) It may be selected from the group consisting of.

In the present invention, the amplification may be characterized in that it is performed by a real-time polymerase chain reaction (PCR) method.

In the present invention, two or more target nucleic acids are used, and the reporter labeled on the PNA probe is different for each target nucleic acid, and at least one bacterial species of Vibrio is identified or detected through detection of two or more target nucleic acids. have.

In the present invention, the "sample sample" includes various samples, and preferably, a biosample is analyzed using the method of the present invention. More preferably, it may be a sample mixed with a bacterial species of Vibrio described in the present invention or a sample of an individual infected with the bacteria (eg, fish, etc.), and organisms of plant, animal, human, fungus, bacteria and virus origin. The sample can be analyzed. When analyzing a sample of mammalian or human origin, the sample may be derived from a specific tissue or organ. Representative examples of tissue include connective, skin, muscle, or nervous tissue. Representative examples of organs include eyes, brain, lung, liver, spleen, bone marrow, thymus, heart, lymph, blood, bone, cartilage, pancreas, kidney, gallbladder, stomach, small intestine, testicle, ovary, uterus, rectum, nervous system, Includes glandular and internal blood vessels. The biological sample to be analyzed includes any cells, tissues, fluids from biological sources, or any other medium that can be well analyzed by the present invention, which is human, animal, human or animal consumption. Samples obtained from foods prepared for use are included. In addition, biological samples to be analyzed include bodily fluid samples, which include blood, serum, plasma, lymph, breast milk, urine, feces, ocular fluid, saliva, semen, brain extract (e.g., brain crush), spinal fluid, appendix, spleen. And tonsil tissue extract, but is not limited thereto.

"Target nucleic acid", "synthetic DNA" or "artificial oligo" of the present invention means a nucleic acid sequence (including SNP) to be detected or not, and "target gene" encoding a protein having physiological and biochemical functions It contains a specific site of the nucleic acid sequence of, and is annealed or hybridized with a primer or probe under conditions of hybridization, annealing or amplification.

"Hybridization" of the present invention means that complementary single-stranded nucleic acids form double-stranded nucleic acids. Hybridization can occur when the complementarity between the two nucleic acid strands is perfect match or even in the presence of some mismatched bases. The degree of complementarity required for hybridization may vary according to hybridization conditions, and in particular, may be controlled by temperature.

In the present invention, the melting curve analysis may be characterized by performing a fluorescence melting curve analysis (FMCA) method.

The PNA probe containing the reporter and quenching of the present invention generates a fluorescent signal after hybridization with the target nucleic acid, and as the temperature rises, it rapidly melts with the target nucleic acid at the appropriate melting temperature of the probe, resulting in a fluorescent signal. Is quenched, and the presence or absence of base denaturation (including SNP) of the target nucleic acid can be detected through high-resolution melting curve analysis obtained from the fluorescence signal according to the temperature change. The PNA probe shows an expected melting temperature (Tm) value when it achieves a perfect match with a target nucleic acid sequence, but a melting temperature lower than expected due to incomplete hybridization with a target nucleic acid in which a base mutation exists. It is characterized by showing the (Tm) value.

The "base mutation" of the present invention is characterized in that the mutation occurs in the base sequence of the target nucleic acid, and includes not only single nucleotide polymorphism (SNP), but also mutation by substitution, deletion or insertion of a base. , The PNA probe of the present invention can be analyzed through melting curve analysis that mutations occur due to substitution, deletion, or insertion of the SNP of the target nucleic acid or the base of the target nucleic acid.

In the PNA probe of the present invention, a reporter and a fluorescent material of a quencher capable of quenching reporter fluorescence may be combined at both ends.

The reporter is FAM (6-carboxyfluorescein), Texas red, HEX (2',4',5',7',-tetrachloro-6-carboxy-4,7-dichlorofluorescein), Quasar, JOE, Cy3 and It may be one or more selected from the group consisting of Cy5, and the quencher may be one or more selected from the group consisting of 6-carboxytetramethyl-rhodamine (TAMRA), BHQ1, BHQ2, and Dabcyl, but is not limited thereto, and preferably Dabcyl (FAM-labeled) can be used.

The Tm value is also changed according to the difference between the nucleotide of the PNA probe and the nucleotide of the DNA complementarily bound thereto, making it easy to develop an application using this. PNA probes are analyzed using a hybridization method different from the hydrolysis method of TaqMan probes, and probes that play a similar role include molecular beacon probes and scorpion probes. There is.

For single-nucleotide polymorphism (SNP) analysis using a PNA probe, it is sufficient to first need only a probe using the base of the part containing the SNP and a forward/reverse primer set for PCR. For the PCR conditions, an existing method can be used, and a melting process is required after PCR is completed, and the Tm value is obtained by measuring the fluorescence intensity every 0.5°C increment. In particular, general real-time PCR (real-time PCR) devices are widely used and have the advantage of not requiring additional program purchases or detailed temperature changes such as HRM (high resolution melting).

The melting curve analysis of the present invention is a method of analyzing the melting temperature of a double-stranded nucleic acid formed of a target nucleic acid, DNA or RNA, and a probe. Since such a method is performed by, for example, Tm analysis or analysis of the melting curve of the double chain, it is called a melting curve analysis. A hybrid (double-stranded DNA) between the target single-stranded DNA of the detection sample and the probe is formed by using a probe complementary to the detection target sequence containing the mutation for detection (including SNP). Subsequently, the hybrid formed body is subjected to a heat treatment, and dissociation (melting) of the hybrid according to the temperature increase is detected by fluctuations in signals such as absorbance. Then, by determining the Tm value based on the detection result, it is a method of determining the presence or absence of a point mutation (including SNP). The Tm value is higher as the homology of the hybrid-formed body is higher, and lower as the homology is lower. For this reason, a Tm value (evaluation reference value) is obtained in advance for a hybrid formed body of a detection target sequence containing a point mutation and a probe complementary thereto, and a Tm value (measurement) between the target single-stranded DNA of the detection sample and the probe Value), and if the measured value is the same degree as the evaluation reference value, it can be determined that there is a match, that is, a mutation (including SNP) in the target DNA, and if the measured value is lower than the evaluation reference value, a mismatch, that is, the target DNA It can be determined that there is no mutation in the.

The fluorescence melting curve analysis of the present invention is a method of analyzing a melting curve using a fluorescent material, and more specifically, the melting curve may be analyzed using a probe containing a fluorescent material. The fluorescent material may be a reporter and a quencher, and may be an intercalating fluorescent material.

In the real-time PCR (Real-Time Polymerase Chain Reaction) method of the present invention, a fluorescent substance is interchelated to a double-stranded DNA chain in the PCR process, and the temperature is raised along with the amplification of the PCR product. The base between the normal control and the mutation (including SNP) is analyzed by analyzing the pattern of the melting curve, in which the amount of fluorescent substance present between the double strands of DNA is reduced by unwinding the double strands, especially the temperature (Tm) at which the DNA is melted (denatured). The presence or absence of a sequence mutation can be analyzed.

Hereinafter, the present invention will be described in more detail through examples. These examples are for illustrative purposes only, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not construed as being limited by these examples.

[ Example One] Vibrio Gene for identification and detection Marker , And the bacterium-specific primer and PNA probe production

Sanger sequencing was performed on the nucleotide sequence of 16S rDNA or dnaJ gene in order to differentiate the genotype of the bacterial 16S rDNA or dnaJ gene targeting 38 species of bacteria isolated from fish such as halibut from Korea among the bacteria that cause fish infection. CLC Genomic workbench 8.0.1 was used to prepare a corresponding consesus sequence for each bacterial species, and compared and analyzed using clustal W alignment. Eight kinds of Vibrio bacteria were analyzed by genetic analysis: Vibrio harvey (V. harvey ), Vibrio scophthalmi (V. scophthalmi), Vibrio ichyoenteri (V. ichtyoenteri), photobacterium damselae (P. damselae), and Vibrio pisces. Identification and identification of Vibrio bacterial species and base sites specific for cherry ( V. fischeri ), Vibrio alginoriticus (V. alginolyticus), Vibrio anguillarium (V. anguillarium), and Vibrio splendidus (V. splendidus) It was selected as a genetic marker for detection.

A set is brio , Photobacterium It is a set of primers for detection of the genus Vibrionaceae, including.

Set B includes V. harvey , V. scophthalmi , V. ichtyoenteri , and Photobacterium damselae , while Set C contains Vibrio pieces. A primer set for detection of cherry ( V. fischeri ), Vibrio alginoriticus (V. alginolyticus), Vibrio anguillarium (V. anguillarium), and Vibrio splendidus (V. splendidus) is included.

In order to confirm the presence or absence of the Vibrio bacteria and to use it for detection, the primer sequences in Table 1 were used. Specifically, the A SET primer was a specific primer of 16S rDNA for discrimination of the genus of Vibrionaceae, and a common primer 27F of bacterial 16s rDNA was produced as a forward primer, and a Viph R1 primer common to the genus Vibrionaceae was produced. The B SET primer is a 16s rDNA specific primer, which is a common VibF1A primer and a VibR1A primer of all species of Vibrio and Photobacteium, and the C SET primer is a 16s rDNA specific primer that is common to all species of Vibrio and Photobacterium As primers for amplification of VibF2B, VibR2, and dnaJ genes, dnaJF2 and dnaJR1 were prepared.

The PNA probe used in the present invention was designed using a PNA probe designer (Applied Biosystems, USA), and was prepared by including a bacterial-specific nucleotide sequence, a reporter, and a quencher in the PNA probe. At this time, the PNA probe was prepared by combining FAM, HEX, TexasRed, and Cy5, respectively, so as not to contain the same fluorescence (Table 1).

All PNA probes (FAM-labeled, Dabcyl) used in the present invention were synthesized in Panagene (Panagene, Korea) by HPLC purification method, and the purity of all synthesized probes was confirmed by mass spectrometry (for effective binding to target nucleic acids. The unnecessary secondary structure of the probe was avoided).

Figure 1-6 is a bacterium of the eight kinds in accordance with the present invention the 16S rDNA (V. harvey, V. scophthalmi, V. ichtyoenteri, P. damselae, V. fischeri, V. alginolyticus, V. anguillarium, V. splendidus) Alternatively, it is a nucleotide sequence diagram showing an example of the nucleotide sequence of a part of the dnaJ gene and the SNP and the peptide nucleic acid (PNA) derived therefrom, and the nucleotide sequence of the selected marker site is indicated in red.

7 to 8 are analysis of the Tm parameter of the PNA probe of Vibrio bacteria included in the A to C SET, and the nucleotide sequence for each PNA probe is indicated in yellow. In addition, Figures 9 to 10 analyze the bonding temperature of the PNA probe corresponding to the B SET and C SET, respectively. 11 to 14 show primers corresponding to B SET and C SET, and the nucleotide sequences of the selected primer sites are indicated in yellow.

As a result, the gene marker, primer sequence, and PNA probe sequence (Table 1) according to the present invention were determined.

division designation Sequence (5' -> 3') Sequence number target primer Vib F1A TACTGGGCGTAAAGCGCAT One V. harvey,
V. scophthalmi,
V. ichtyoenteri
P.damselae Vib R1A GCGTTAGCTCCGAAAGCC 2 Vib F2B GGACGGGTGAGTAATGCC 3 V. fischeri,
V. alginolyticus , V. anguillarium,
V. splendidus Vib R2 CCCGGGCTTTCACATCT 4 dnaJ F2 CCGCAAAGAAGCCTTGG 5 V. ichtyoenteri dnaJ R1 CGATATCTTCGGCGATGTG 6 27F AGAGTTTGATCCTGGCTCAG 7 Vibrio, Photobacterium Viph R1 CCCGGGCTTTCACATCT 8 PNA probe ViPh Dabcyl-AGCGCATGCAGG-O-K (Quasar) 9 Vibrio, Photobacterium
Har_4 Dabcyl-CGGGTCAAAGA-O-K (FAM) 10 V. harvey ich, sco_3 Dabcyl-ATAGCGTAATTATTTGAC-O-K (Texas red) 11 V. ichtyoenteri,
V. scophtahalmi dam_1 Dabcyl-GGCGGCCTGTTA-O-K (HEX) 12 P. damselae dnaJ_1 Dabcyl-CGAACCACGTTGT-O-K (Cy5) 13 V. ichtyoenteri Alg_2 Dabcyl-CTCGGAATAGCATTTG-O-K (HEX) 14 V. alginolyticus Ang_1 Dabcyl-TGGTGGATTAAGT-O-K (Texas-Red) 15 V. anguillarium Spl_2 Dabcyl-ACAGACACTGACA-O-K (Cy5) 16 V. splendidus Fish_1 Dabcyl-GGTTGTTCCCTTGAG-O-K (FAM) 17 V. fischeri 16S rDNA marker V. harvey_16S rDNA marker CGGGTCAAAGA 18 V. harvey V. scophthalmi & V. ichtyoenteri _16S rDNA marker ATAGCGTAATTATTTGAC 19 V. scophthalmi,
V. ichtyoenteri P. damselae _16S rDNA marker GGCGGCCTGTTA 20 P. damselae V. fischeri_16S rDNA marker GGTTGTTCCCTTGAG 21 V. fischeri V. alginolyticus_16S rDNA marker CTCGGAATAGCATTTG 22 V. alginolyticus V. anguillarium_16S rDNA marker TGGTGGATTAAGT 23 V. anguillarium V. splendidus_16S rDNA marker ATAGCGTAATTATTTGAC 24 V. splendidus 16S rDNA marker Vibrionaceae genus _16S rDNA marker AGCGCATGCAGG 25 Vibrio sp
Photobacterium sp . dnaJ marker V. ichtyoenteri_dnaJ marker CGAACCACGTTGT 26 V. ichtyoenteri

(In Table 1, Dabcyl means quencher, Quasar, FAM, Texas red, HEX, and Cy5 means reporter.)

[ Example 2] Real time PCR (Real-Time Polymerase Chain Reaction) and a method of discriminating bacterial genes through analysis of the melting curve

Example 1 Bacterial specific gene markers, using the PNA probe and primer, 8 types of bacteria (V. harvey, scophthalmi V., V. ichtyoenteri, P. damselae, V. fischeri, V. alginolyticus, V. anguillarium , V. splendidus ) for DNA samples were derived amplification curves and dissolution curves, and analyzed them to determine bacterial species. 16 shows the configuration of PCR for diagnosis of Vibrio infection.

PCR was performed using a CFX96™ Real-Time system (BIO-RAD, USA), and all experimental conditions used asymmetric PCR to generate a single-stranded target nucleic acid. Conditions for asymmetric PCR are as follows; 2X PNA qPCR PCR MasterMix (Sisun Biomaterials, Korea), 0.1 μM forward primer and 1 μM reverse primer, 4 kinds of PNA probe mixture 1 μM, 10 ng bacterial-derived DNA so that the total volume is 20 μl. After addition, real-time PCR was performed.

FIG. 17 shows the reaction conditions of real-time PCR for discrimination and detection of bacterial species, and a graph shows a process of amplifying and hybridizing a gene marker site of bacterial-derived DNA, and increasing the temperature of the hybridized product. Here, the real-time PCR process was denatured at 95°C for 10 minutes, then reacted at 95°C for 30 seconds, 58°C for 45 seconds, and 74°C for 45 seconds, and this was repeated 40 cycles, and fluorescence was measured in real time. . The melting curve analysis was performed by performing a denaturation step at 95° C. for 5 minutes, then increasing the fluorescence at 80° C. for 30 seconds, 60° C. for 30 seconds, and 45° C. to 80° C. by 1° C. and measuring fluorescence.

As a result, as shown in Figs. 18 to 21, each of the peptide nucleic acids selected from SEQ ID NOs: 18 to 26 is used in bacterial DNA samples ( V. harvey, V. scophthalmi , V. ichtyoenteri, P. damselae , V. fischeri). , V. alginolyticus , V. anguillarium , V. splendidus ), amplification curves for each bacteria and melting curves for each fluorescence could be obtained.

In addition, as shown in Figs. 18 and 21, real-time PCR is performed in one tube at the same time to analyze the melting curve for each set. A SET 8 bacteria and B SET 3 bacteria ( V. harvey, V. scophthalmi , V. ichtyoenteri ), C SET 4 kinds of bacteria ( V. fischeri , V. alginolyticus , V. anguillarium , V. splendidus ) were capable of multi-detection.

When the above results were put together, it was possible to individually detect bacteria or to discriminate bacterial species from samples in which different bacterial species were mixed.

[ Example 3] Bacteria DNA use Diagnostic kit Sensitivity and Real-time PCR Specificity and sensitivity analysis

A kit sensitivity analysis for DNA of Vibrio bacteria was performed using a multiplex assay kit including a PNA probe and a primer according to the present invention. The sensitivity analysis was performed using 10-fold dilution of standard strain DNA (100ng~0.01ng), and the efficiency of quantitative analysis was compared using the Ct value of each fluorescence.

As a result, as a result of analyzing the melting peak and the amplification curve, both of the diagnostic PCR sets showed high sensitivity of 0.01 ng DNA detection (FIGS. 22 to 23). Fig. 22 shows the results in B SET, and Fig. 23 shows the results in C CET. Figure 12 shows (A) V. harvey, (B) V. scophthalmi, (C) V. ichtyoenteri, and Figure 23 (A) V. alginolyticus, (B) V. fischeri, (C) V. anguillarium, (D) ) V. splendidus.

In addition, in order to be applied to the diagnostic procedure for testing fish disease bacteria present in the tissues of the actual flounder, the PNA probe, primer, PCR reaction product according to the present invention, and the prototype of the diagnostic kit operated under temperature conditions, and the flounder DNA and the bacterial DNA are Using the mixed sample, the efficiency of the test according to the presence or absence of flounder DNA was confirmed. Specifically, the analysis was performed using a standard strain (100,000 ~ 10 colony) subjected to 10-fold dilution, and the efficiency of quantitative analysis was compared using the Ct value of each fluorescence.

As a result, detection of up to 10 colony was possible in all PCR sets, and it was confirmed that there was no "cross-reaction" according to the presence or absence of flounder DNA, which proved that the specificity and sensitivity were high (FIG. 25).

As described above, specific parts of the present invention have been described in detail, and it will be apparent to those of ordinary skill in the art that these specific techniques are only preferred embodiments, and the scope of the present invention is not limited thereby. will be. Accordingly, it will be said that the substantial scope of the present invention is defined by the appended claims and their equivalents.

<110> National Institute of Fisheries Science <120> Genetic Marker for Discrimination and Detection of Vibriosis in fish and Method for Discrimination and Detection of Vibriosis in fish Using the Same <130> P17-B196 <160> 26 <170> KopatentIn 2.0 <210> 1 <211> 19 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 1 tactgggcgt aaagcgcat 19 <210> 2 <211> 18 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 2 gcgttagctc cgaaagcc 18 <210> 3 <211> 18 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 3 ggacgggtga gtaatgcc 18 <210> 4 <211> 17 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 4 cccgggcttt cacatct 17 <210> 5 <211> 17 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 5 ccgcaaagaa gccttgg 17 <210> 6 <211> 19 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 6 cgatatcttc ggcgatgtg 19 <210> 7 <211> 20 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 7 agagtttgat cctggctcag 20 <210> 8 <211> 17 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 8 cccgggcttt cacatct 17 <210> 9 <211> 12 <212> DNA <213> Artificial Sequence <220> <223> PNA porbe <400> 9 agcgcatgca gg 12 <210> 10 <211> 11 <212> DNA <213> Artificial Sequence <220> <223> PNA porbe <400> 10 cgggtcaaag a 11 <210> 11 <211> 18 <212> DNA <213> Artificial Sequence <220> <223> PNA porbe <400> 11 atagcgtaat tatttgac 18 <210> 12 <211> 12 <212> DNA <213> Artificial Sequence <220> <223> PNA porbe <400> 12 ggcggcctgt ta 12 <210> 13 <211> 13 <212> DNA <213> Artificial Sequence <220> <223> PNA porbe <400> 13 cgaaccacgt tgt 13 <210> 14 <211> 16 <212> DNA <213> Artificial Sequence <220> <223> PNA porbe <400> 14 ctcggaatag catttg 16 <210> 15 <211> 13 <212> DNA <213> Artificial Sequence <220> <223> PNA porbe <400> 15 tggtggatta agt 13 <210> 16 <211> 13 <212> DNA <213> Artificial Sequence <220> <223> PNA porbe <400> 16 acagacactg aca 13 <210> 17 <211> 15 <212> DNA <213> Artificial Sequence <220> <223> PNA porbe <400> 17 ggttgttccc ttgag 15 <210> 18 <211> 11 <212> DNA <213> Artificial Sequence <220> <223> 16S rDNA marker for V. harvey <400> 18 cgggtcaaag a 11 <210> 19 <211> 18 <212> DNA <213> Artificial Sequence <220> <223> 16S rDNA marker for V. scophthalmi and V. ichtyoenteri <400> 19 atagcgtaat tatttgac 18 <210> 20 <211> 12 <212> DNA <213> Artificial Sequence <220> <223> 16S rDNA marker for P. damselae <400> 20 ggcggcctgt ta 12 <210> 21 <211> 15 <212> DNA <213> Artificial Sequence <220> <223> 16S rDNA marker for V. fischeri <400> 21 ggttgttccc ttgag 15 <210> 22 <211> 16 <212> DNA <213> Artificial Sequence <220> <223> 16S rDNA marker for V. alginolyticus <400> 22 ctcggaatag catttg 16 <210> 23 <211> 13 <212> DNA <213> Artificial Sequence <220> <223> 16S rDNA marker for V. anguillarium <400> 23 tggtggatta agt 13 <210> 24 <211> 13 <212> DNA <213> Artificial Sequence <220> <223> 16S rDNA marker for V. splendidus <400> 24 acagacactg aca 13 <210> 25 <211> 12 <212> DNA <213> Artificial Sequence <220> <223> 16S rDNA marker for Vibrio sp. and Photobacterium sp. <400> 25 agcgcatgca gg 12 <210> 26 <211> 13 <212> DNA <213> Artificial Sequence <220> <223> dnaJ marker for V. ichtyoenteri <400> 26 cgaaccacgt tgt 13

Claims (7)

A primer capable of detecting the gene represented by the nucleotide sequence of SEQ ID NO: 21 to SEQ ID NO: 26 and a primer capable of detecting the gene represented by Vibrio fischeri , Vibio fischeri , alginolyticus , Vibrio anguillarium , and Vibrio splendidus. &lt; Desc / Clms Page number 2 &gt;
2. The composition according to claim 1, wherein the primer is a pair of primers represented by the nucleotide sequences of SEQ ID NOS: 1 and 2.
The composition of claim 1, wherein the probe is bound to at least one of a reporter and a quencher.
4. The method of claim 3, wherein the reporter is selected from the group consisting of 6-carboxyfluorescein, Texas red, HEX (2 ', 4', 5 ', 7', - tetrachloro-6-carboxy-4,7-dichlorofluorescein) Quasar, JOE, Cy3 and Cy5.
4. The composition of claim 3, wherein the quencher is selected from the group consisting of 6-carboxytetramethyl-rhodamine (TAMRA), BHQ1, BHQ2, and Dabcyl.
The identification of a Vibrio ficus selected from the group consisting of Vibrio fischeri , Vibio alginolyticus , Vibrio anguillarium and Vibrio splendidus , comprising the steps of: Or detection method:
(a) extracting a target nucleic acid from a specimen sample;
(b) a primer capable of detecting at least one gene among the genes represented by the nucleotide sequences of SEQ ID NOS: 21 to 26, and a probe represented by SEQ ID NO: 14 to SEQ ID NO: 17, Amplifying and hybridizing the gene of &lt; RTI ID = 0.0 &gt;
(c) obtaining a temperature-dependent melting curve while increasing the temperature of the hybridized product in step (b); And
(d) detecting Vibrio fungi from the melting temperature through analysis of the melting curve obtained in step (c), or determining whether the fish is infected with the bacterium species.
7. The method according to claim 6, wherein the primer is a pair of primers represented by the nucleotide sequences of SEQ ID NOS: 1 and 2.

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