Staphylococcus aureus MntC protective epitope peptide, epitope vaccine and preparation method and application thereof

Abstract

The invention discloses a staphylococcus aureus MntC protective epitope peptide, an epitope vaccine as well as a preparation method and application of the staphylococcus aureus MntC protective epitope peptide and the epitope vaccine, the protective B cell epitope peptide Loop101 of a staphylococcus aureus MntC antigen is obtained, the novel epitope vaccine MntC101 is successfully constructed based on the epitope, after the vaccine is inoculated, an anti-Loop101 antibody can be efficiently induced in SPF and staphylococcus aureus pre-infected mice, and the staphylococcus aureus MntC protective epitope peptide and the novel epitope vaccine MntC101 can be used for preparing the staphylococcus aureus MntC protective epitope peptide. SPF and pre-infected mice can be effectively protected from being infected with staphylococcus aureus, and the method has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the field of antibodies, in particular to a Staphylococcus aureus MntC protective epitope peptide, an epitope vaccine, a preparation method thereof, and an application of the vaccine. Background Art

[0002] Staphylococcus aureus (SA), commonly known as S. aureus, is a major pathogen causing clinically fatal infections such as pneumonia and sepsis. Due to the rapid development of antibiotic resistance, clinical treatment options for drug-resistant S. aureus are becoming increasingly limited. Vaccines are currently recognized as an effective means of combating drug-resistant infections, but no effective S. aureus vaccine is currently available. After recovery from a S. aureus infection, the immune imprint formed in the human body does not protect against subsequent infection. Studies have shown that this non-protective immune imprint against S. aureus may be one of the factors hindering the successful development of a S. aureus vaccine.

[0003] Manganese transporter protein C (MntC) is an extracellular manganese-binding lipoprotein of the Staphylococcus aureus ABC transporter complex. It is highly expressed during the early stages of infection and anchored to the S. aureus cell wall. By transporting manganese ions, it enhances the host's antioxidant defenses, enabling infection. Preclinical studies in SPF animals have demonstrated that MntC has good immunogenicity, producing high levels of anti-MntC antibodies after vaccination and providing protection against S. aureus infection in mice. MntC is a component of vaccines being developed by several international pharmaceutical companies, including Pfizer. However, clinical trials of this vaccine have been unsuccessful, and related studies have shown that MntC is unable to protect hosts with a S. aureus immune signature from reinfection. This suggests that unoptimized MntC vaccines may not be effective in establishing a protective immune signature against S. aureus in individuals with a history of infection.

[0004] Designing novel vaccines based on MntC that avoid inducing non-protective immune imprinting and precisely induce protective immune responses may be key to the successful development of MntC-based vaccines. Epitope vaccines are a proven effective strategy for precisely inducing antibodies against specific epitopes. To date, no protective B cell epitopes of MntC have been reported. Discovering protective B cell epitopes of MntC and constructing epitope vaccines based on these newly discovered epitopes could provide an effective new strategy to overcome the interference of human immune imprinting with the protective efficacy of MntC vaccines. Summary of the Invention

[0005] In view of this, one object of the present invention is to provide a Staphylococcus aureus MntC protective epitope peptide; a second object of the present invention is to provide a vaccine based on the Staphylococcus aureus MntC protective epitope peptide; a third object of the present invention is to provide a method for preparing the Staphylococcus aureus MntC protective epitope peptide vaccine; a fourth object of the present invention is to provide use of the Staphylococcus aureus MntC protective epitope peptide vaccine for efficiently and specifically inducing anti-Loop101 antibodies in SPF and mice infected with Staphylococcus aureus; a fifth object of the present invention is to provide use of the Staphylococcus aureus MntC protective epitope peptide vaccine for protecting against Staphylococcus aureus infection in SPF and mice infected with Staphylococcus aureus.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A protective epitope peptide of Staphylococcus aureus MntC, the sequence of which is shown in SEQ ID NO.1.

[0007] The vaccine based on the Staphylococcus aureus MntC protective epitope peptide has an amino acid sequence as shown in SEQ ID NO.2.

[0008] Preferably, the nucleotide sequence of the vaccine is shown in SEQ ID NO.3.

[0009] The preparation method of the Staphylococcus aureus MntC protective epitope peptide vaccine comprises the following steps: ligating the sequence shown in SEQ ID NO. 3 into the EcoR I and Xho I restriction sites of the PGEX-6P-2 vector, and then expressing the vaccine in Escherichia coli and purifying the vaccine.

[0010] 4. Application of the Staphylococcus aureus MntC protective epitope peptide vaccine to efficiently and specifically induce anti-Loop101 antibodies in SPF mice and mice infected with Staphylococcus aureus.

[0011] 5. Use of the vaccine containing the protective epitope peptide of MntC of Staphylococcus aureus in protecting SPF mice and mice infected with Staphylococcus aureus from Staphylococcus aureus infection.

[0012] The present invention has the beneficial effects of obtaining a protective B cell epitope peptide, Loop101, of the Staphylococcus aureus MntC antigen and successfully constructing a novel epitope vaccine, MntC101, based on this epitope. After vaccination, this vaccine efficiently induces anti-Loop101 antibodies in SPF mice and mice pre-infected with S. aureus, effectively protecting these mice from S. aureus infection and possessing promising application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to make the purpose, technical solutions and beneficial effects of the present invention more clear, the present invention provides the following drawings for illustration: Figure 1 Binding curves of manganese ions with MntC protein and MntCΔLoop101; Figure 2 Residual manganese ions in the culture medium of wild Staphylococcus aureus and knockout Loop101 Staphylococcus aureus; Figure 3 Figure 3. Bacterial load and skin necrosis in mice infected with wild-type Staphylococcus aureus and Loop101 knockout Staphylococcus aureus (a: peritoneal lavage fluid in peritonitis model; b: lung tissue homogenate in pneumonia model; c: liver tissue homogenate in bacteremia model; d: ulcer area in skin model). Figure 4 Design a schematic diagram for the MntC101 protein; Figure 5 This is the result of MntC101 protein purification; Figure 6 The results of MntC and MntCΔLoop101 protein purification are shown; Figure 7 MntC101 efficiently induces anti-Loop101 antibodies; Figure 8 MntC101 has a protective effect against Staphylococcus aureus infection. DETAILED DESCRIPTION

[0014] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0015] Example 1 The sequence of the protective B cell epitope peptide Loop101 of Staphylococcus aureus MntC was analyzed, and the amino acid sequence was as follows: AVSKDVKPIYLNGEEGNKDKQDPHAW (SEQ ID NO. 1).

[0016] Acquisition of the protective epitope peptide: MntC mainly exerts its pathogenic function by acquiring manganese ions. It was found through experiments that Figure 1 Isothermal titration calorimetry (ITC) assays showed that wild-type MntC still had the ability to bind manganese ions, while the MntC protein with loop101 deletion (MntCΔloop101) lost its ability to bind manganese ions. Figure 2 Mass spectrometry showed that wild Staphylococcus aureus can reduce the manganese ion content in the culture medium by absorbing manganese ions, while the ability of Staphylococcus aureus with loop101 deletion (MntCΔloop101) to absorb manganese ions in the culture medium was significantly reduced. Figure 3As shown, S. aureus strains lacking loop101 (MntCΔloop101) exhibited significantly reduced survival in skin, lung, peritoneal, and bloodstream infection models. These results suggest that loop101 is a key epitope of MntC in its pathogenicity. If vaccines can induce antibodies targeting loop101 without producing antibodies targeting other MntC epitopes, it may be possible to mitigate non-protective immune responses induced by vaccination.

[0017] The MntC101 epitope vaccine sequence constructed based on the epitope peptide Loop101 sequence: The vaccine protein uses a protein carrier. To avoid the production of antibodies against other epitopes of MntC after vaccination, ZnuA, which has a very similar structure to MntC but has poor sequence similarity, is used as a carrier for recombinant expression, such as Figure 4 shown.

[0018] MntC101 amino acid sequence: AVVASLKPVGFIASAIADGVTETEVLLPDGASEHDYSLRPSDVKRLQNADLVVWVGPEMEAFMQKPVSKLPGAKQVTIAQLEDVKPLAVSKDVKPIYLNGEEGNKDKQDPHAWLSPEIARATAVAIHGKLVELM PQSRAKLDANLKDFEAQLASTETQVGNELAPLKGKGYFVFHDAYGYFEKQFGLTPLGHFTVNPEIQPGAQRLHEIRTQLVEQKATCVFAEPQFRPAVVESVARGTSVRMGTLDPLGTNIKLGKTSYSEFLSQLANQYASCLKGD (SEQ ID NO.2).

[0019] MntC101蛋白编码DNA序列:GGATCCCGCTGTGGTGGCAAGTCTGAAACCGGTGGGCTTTATTGCAAGCGCAATTGCAGATGGCGTGACCGAAACCGAAGTTCTGCTGCCGGATGGCGCCAGCGAACATGATTATAGTCTGCGCCCGAGTGATGTGAAACGTCTGCAGAATGCAGATCTGGTTGTTTGGGTGGGTCCGGAAATGGAAGCATTTATGCAGAAACCGGTGAGCAAACTGCCGGGTGCAAAACAGGTTACCATTGCACAGCTGGAAGATGTGAAACCGCTGGCCGTTAGTAAAGATGTTAAACCGATTTATCTGAACGGCGAAGAAGGCAATAAAGATAAACAGGACCCTCATGCATGGCTGAGCCCGGAAATTGCCCGTGCCACCGCCGTGGCCATTCATGGTAAACTGGTGGAACTGATGCCGCAGAGCCGCGCAAAACTGGATGCCAATCTGAAAGATTTTGAAGCACAGCTGGCAAGCACCGAAACCCAGGTTGGTAATGAACTGGCCCCGCTGAAAGGCAAAGGCTATTTTGTGTTTCATGATGCCTATGGTTATTTTGAAAAGCAGTTTGGTCTGACCCCGCTGGGCCATTTTACCGTGAATCCGGAAATTCAGCCGGGTGCCCAGCGCCTGCATGAAATTCGCACCCAGCTGGTTGAACAGAAAGCAACCTGTGTTTTTGCAGAACCGCAGTTTCGCCCGGCCGTTGTGGAAAGTGTTGCACGTGGCACCAGTGTTCGCATGGGTACCCTGGACCCTCTGGGCACCAATATTAAACTGGGTAAAACCAGTTATAGCGAATTTCTGAGTCAGCTGGCAAATCAGTATGCAAGCTGCCTGAAAGGTGATTAACTCGAG(SEQ ID NO.3)。下划线分别表示EcoRI酶切位点,XhoⅠ酶切位点。

[0020] 实施例2 Construction of MntC101 expression vector: PGEX-6P-2 vector and the DNA sequence of MntC101 were digested by restriction enzymes EcoRI and XhoI, and then the vector and the target gene fragment were ligated by DNA ligase. After being screened by ampicillin (Amp) resistance in E. coli, the E. coli containing the expression vector was amplified, and the expression vector was obtained by plasmid extraction.

[0021] The vaccine preparation method: Expression vector transformation: 50 μL of BL21 competent cells were added to a new sterile EP tube, 2 μL of dissolved expression vector aqueous solution was added, and the EP tube was placed in an ice box for incubation on ice for 30 min. The EP tube was subjected to heat shock treatment in a water bath at 42°C for 90 s, immediately taken out, and placed on ice for incubation for 2 min 30 s to terminate the heat shock reaction. 500 μL of LB medium was added to the EP tube, mixed gently, and then the EP tube was placed in a 37°C shaker for 45 min of vibration culture at a speed of 220 rpm. 20 μL of the recovered bacterial liquid was dropped on an LB plate containing 100 μg / mL of Amp. The bacterial liquid was evenly coated with a disposable L rod, and the plate was inverted and placed in a 37°C bacterial incubator for overnight culture.

[0022] Protein expression: Pick a single colony from LB solid medium and inoculate it into 5 mL of LB liquid medium containing 100 µg / mL Amp. Incubate the culture overnight at 37°C in a shaking incubator at 220 rpm. Transfer 200 µL of the overnight culture to 20 mL of LB liquid medium containing 100 µg / mL Amp. Maintain the temperature at 37°C and shake at 220 rpm overnight. Inoculate 20 mL of the overnight culture into 2 L of LB medium containing 100 µg / mL AMP. Maintain the temperature at 37°C and shake at 220 rpm for approximately 3 h. The OD600nm value of the culture medium was monitored spectrophotometrically. Cultivation was terminated when the OD600nm value reached the range of 0.6–1.0, indicating optimal induction of expression. Isopropyl-1thio-β-D-galactoside (IPTG) was added to 2 L of culture medium to a final concentration of 1 mM. The culture was then shaken at 220 rpm at 37°C for 3 h. Bacteria were harvested by centrifugation, added to 50 mL of PBS, and thoroughly resuspended using a vortexer. While incubating on ice, the culture was disrupted in an ultrasonic disruptor until it became translucent or watery. Ultrasonication parameters were set as follows: power ≤40%, 9 s on, 9 s off, for a total sonication time of approximately 20 min. The culture was carefully balanced and aliquoted into specially designed high-speed centrifuge tubes. Centrifugation was performed at 12,000 rpm for 20 min at 4°C. The supernatant after centrifugation was filtered through a 0.45 µM filter and collected in a 50 mL centrifuge tube for subsequent purification steps.

[0023] Protein purification: (1) Affinity chromatography (GST tag): ① Preparation of affinity chromatography column: Add 3 mL of GST-tagged beads to the affinity chromatography column and wash the beads with 30 mL of PBS buffer three times to ensure that the beads are fully balanced before proceeding to the next step; ② Protein Binding: Add the sterile-filtered protein supernatant obtained from protein expression to an affinity chromatography column, seal it with sealing film, and then place the column on a rotary shaker in a 4°C refrigerator and incubate overnight to allow the target protein to fully bind to the GST-tagged beads. Remove the affinity chromatography column from the refrigerator, remove the bound liquid, and wash the beads three times with 25 mL of PBS buffer each time. After washing, carefully transfer the overnight bound beads to a small chromatography column. Add 3 mL of PBS buffer and 2 mL of PreScission Protease to the column, seal it with sealing film, and then place the column on a rotary shaker in a 4°C refrigerator and incubate overnight to cleave the GST tag. The next day, collect the liquid from the column into a 50 mL centrifuge tube for subsequent purification.

[0024] Protein identification: Protein gel configuration: ① Preparation of separation gel: In a 50 mL centrifuge tube, mix the separation gel solution A and solution B from the rapid protein gel kit in a 1:1 ratio. Add an appropriate amount of 10% APS solution and mix thoroughly. Pour the separation gel solution into the electrophoresis mold until the liquid level is approximately 1.5 cm from the top of the glass plate. ②Preparation of stacking gel: Mix stacking gel solution A and solution B in a 1:1 ratio, add an appropriate amount of 10% APS solution, mix well and pour directly into the upper layer of separation gel solution without waiting for the separation gel to solidify; ③ Gel solidification and fixation: Insert the comb into the gel and let it sit for about 20 minutes until the gel is completely solidified. After solidification, fix the gel onto the electrophoresis plate and place it in an electrophoresis tank filled with electrophoresis buffer. Remove the comb.

[0025] (2) Electrophoresis: Add an appropriate amount of electrophoresis buffer to the electrophoresis tank until the gel is completely covered. Take 5 µL of protein marker and 10 µL of sample and add them to the gel wells respectively. Connect the electrodes, turn on the power supply, and adjust the voltage to 100 V. When the band runs through the stacking gel, adjust the voltage to 200 V. Stop electrophoresis when the band runs to about 1.5 cm from the bottom of the gel.

[0026] (3) Staining and destaining: Take the gel out of the electrophoresis tank and place it in instant blue staining solution. Place it on a horizontal shaker and shake for staining. After staining at room temperature for 5 minutes, pour out the staining solution, add an appropriate amount of pure water, and continue to destain on a horizontal shaker until the gel becomes clear and transparent.

[0027] (4) Gel imaging: Use a gel imager to capture the gel image and record the position and intensity of the protein bands. As shown in Figure 5, the purity of the obtained protein can reach more than 95%.

[0028] Example 3 MntC101 efficiently induced anti-Loop101 antibodies in SPF and pre-S. aureus-infected mice.

[0029] Construction of pre-infection mouse model: (1) Mouse grouping: Healthy C57BL / 6 male mice aged 6 to 8 weeks were selected and randomly divided into two groups: the non-pre-infection group and the pre-infection group, with 16 mice in each group. (2) Pre-infection treatment: ① Culture of Staphylococcus aureus and preparation of bacterial solution: Take out the strain from the -80℃ refrigerator, inoculate it onto the blood plate using the three-zone streak method, and place it in a 37℃ incubator for overnight culture. The next day, pick a single colony on the blood plate, inoculate it into 5 mL of TSB liquid culture medium, place it in a 37℃ constant temperature shaker, and shake and culture it at 220 rpm overnight. The next day, inoculate the overnight bacterial solution into LB liquid culture medium at a ratio of 1:100, place it in a 37℃ constant temperature shaker, and shake and culture it at 220 rpm for 2 h until the logarithmic growth phase. Subsequently, centrifuge the cultured bacterial solution at 6000 rpm for 10 min, discard the supernatant, resuspend the bacteria with sterile PBS, and use a UV spectrophotometer to adjust the bacterial solution OD600nm to 1.05. At this time, the bacterial solution concentration is 1×10 9 CFU / mL, dilute the bacterial solution 10 times for later use.

[0030] ② Pre-infection group: mice were intraperitoneally injected once every 7 days with 100 μL of the 10-fold diluted bacterial solution (containing 1×10 7 CFU), a total of 3 injections were performed, and after the last injection, the mice entered the subsequent observation period; ③ Non-pre-infection group: Mice were injected intraperitoneally with 100 µL of sterile PBS buffer every 7 days. The injection time and frequency were the same as those of the pre-infection group, for a total of 3 times.

[0031] Mouse immunization protocol: The mice in the pre-infection group and the non-pre-infection group were randomly divided into the experimental group and the control group, with 8 mice in each group. In the experimental group, 50 μg of MntC101 antigen was mixed with aluminum phosphate adjuvant and adsorbed at 4°C for 1-2 hours to ensure that the antigen and adjuvant are fully combined. Subsequently, the mice were immunized by intraperitoneal injection, 600 μL / mouse. During the operation, the injection site must be accurate to avoid extravasation of the drug solution. The control group used an equal volume of PBS mixed with aluminum phosphate adjuvant, and the immunization operation was the same as that of the experimental group. All mice were immunized on days 0, 7, and 14, for a total of 3 immunizations. On the 7th day after the third immunization, the mouse serum was collected for subsequent antibody detection.

[0032] Antigen sequence for immune serum detection: MntC wild protein amino acid sequence: SSDKSNGKLKVVTTNSILYDMAKNVGGDNVDIHSIVPVGQDPHEYEVKPKDIKKLTDADVILYNGLNLETGNGWFEKALEQAGKSLKDKKVIAVSKDVKPIYLNGEEGNKDKQDPHAWLSLDNGIKYVKTIQQTFID NDKKHKADYEKQGNKYIAQLEKLNNDSKDKFNDIPKEQRAMITSEGAFKYFSKQYGITPGYIWEINTEKQGTPEQMRQAIEFVKKHKLKHLLVETSVDKKAMESLSEETKKDIFGEVYTDSIGKEGTKGDSYYKMMKSNIETVHGSMK (SEQ ID NO.4); DNA sequence: GGATCCAGCAGTGATAAGTCAAATGGCAAACTAAAAGTAGTAACGACGAATTCAATTTTATATGATATGGCTAAAAATGTTGGTGGAGACAACGTCGATATTCATAGTATTGTACCTGTTGGTCAAGATCCTCATGAATATGAAGTTAAACCTAAAGATATTAAAAAGTTAACTGACGCTGACGTTATTTTATACAACGGATTAAATTTAGAGACTGGTAACGGTTGGTTTGAAAAAGCCTTAGAACAGGCTGGTAAATCATTAAAAGATAAAAAAGTTATCGCAGTATCAAAAGATGTTAAACCTATCTATTTAAACGGAGAAGAAGGCAACAAAGATAAACAAGATCCACACGCATGGTTAAGTTTAGATAACGGTATTAAATACGTAAAAACAATTCAACAAACATTTATCGATAACGACAAAAAACATAAAGCAGATTATGAAAAGCAAGGTAACAAATACATTGCTCAATTGGAAAAATTAAATAACGACAGTAAAGACAAATTTAATGACATTCCAAAAGAACAACGTGCCATGATTACAAGTGAAGGTGCCTTCAAGTACTTCTCAAAACAATACGGTATTACACCAGGTTATATTTGGGAAATTAACACTGAAAAACAAGGTACACCAGAACAAATGAGACAAGCTATTGAGTTTGTTAAAAAGCACAAATTAAAACACTTATTAGTAGAAACAAGTGTTGATAAGAAAGCAATGGAAAGTTTATCTGAAGAAACGAAGAAAGATATCTTTGGTGAAGTGTACACAGATTCAATCGGTAAAGAAGGCACTAAAGGTGACTCTTACTACAAAATGATGAAATCAAATATTGAAACTGTACACGGAAGCATGAAATAACTCGAG (SEQ ID NO. 5). The underlined sequences represent EcoRI and XhoI restriction sites, respectively.

[0033] MntC敲除Loop101(MntCΔLoop)蛋白氨基酸序列:SSDKSNGKLKVVTTNSILYDMAKNVGGDNVDIHSIVPVGQDPHEYEVKPKDIKKLTDADVILYNGLNLETGNGWFEKALEQAGKSLKDKKVILSLDNGIKYVKTIQQTFIDNDKKHKADYEKQGNKYIAQLEKLNNDSKDKFNDIPKEQRAMITSEGAFKYFSKQYGITPGYIWEINTEKQGTPEQMRQAIEFVKKHKLKHLLVETSVDKKAMESLSEETKKDIFGEVYTDSIGKEGTKGDSYYKMMKSNIETVHGSMK(SEQ ID NO.6); DNA sequence: (SEQ ID NO. 7). The underlines indicate the EcoRI and XhoⅠ restriction sites, respectively.

[0034] The antigen expression and purification method for detection is the same as the preparation method of MntC101. Figure 6 As shown in the figure, the purity of MntC protein and MntC knockout Loop101 protein can reach more than 95%.

[0035] Elisa method is used to detect whether anti-Loop101 specific antibodies are produced in immune serum: (1) Antigen coating: Dilute the antigens MntC and MntCΔLoop to 10 µg / mL using coating solution and coat the ELISA plate at 1 µg / well. Incubate the ELISA plate in a refrigerator at 4°C overnight, covering it with tin foil to prevent evaporation and contamination. (2) Washing: Run a plate washer using PBST containing 0.5% Tween-20 as the washing solution. The plate washer parameters are set as follows: wash 4 times with PBST, adding 300 µL of solution each time, shaking for 5 seconds, and aspirating for 2.5 seconds. After washing, pat the plate dry; (3) Blocking: Add 100 μL of blocking solution to each well, place the ELISA plate in a 37°C incubator, and let it stand for 1 h; (4) Serum incubation: First, dilute the serum sample to 2000 times with sample diluent, then add 100 μL of diluted serum sample to each well, place the ELISA plate in a 37°C incubator, and incubate for 2 h; (5) Wash the plate: repeat step (2); (6) Incubation with secondary antibody: Dilute the goat anti-mouse antibody 200-fold with sample diluent, add the diluted secondary antibody to the reaction wells of the ELISA plate, 100 μL per well, place the ELISA plate in a 37°C incubator, and incubate for 1 h; (7) Wash the plate: Repeat step (2) again; (8) Color development: Add 100 µL of TMB color development solution to each well in the dark and incubate the ELISA plate in a 37°C incubator for 5–30 min. The optimal time to terminate the reaction is determined by the depth of the color in the well. (9) Termination: When the color reaches the desired depth, quickly add 100 μL of ELISA stop solution to each well to terminate the reaction; (10) Reading the plate: Within 10 minutes after the reaction is terminated, use a multifunctional microplate reader to detect the absorbance of the ELISA plate at a wavelength of 450 nm, record and analyze the data to evaluate the level of antibodies in the sample. Figure 7 As shown, MntC specifically induced the production of anti-Loop101 antibodies in both SPF mice and mice pre-infected with Staphylococcus aureus.

[0036] Example 4 MntC101 protects SPF and pre-infected S. aureus mice from S. aureus infection: strain and mouse preparation and operation steps are the same as above. On the 7th day after the mice were immunized for 3 times, 2×10 8USA300 / Eno-Antares2 Staphylococcus aureus was injected intraperitoneally at a dose of 100 CFUs / mouse. 24 hours later, mice were first injected intraperitoneally with 1% sodium pentobarbital (50 mg / kg). After the mice were anesthetized, the abdominal hair was removed. Subsequently, 100 µL of 3 mM hydrofurimazine was injected intraperitoneally into each mouse. 5 minutes after the injection, the fluorescence signal was detected using an in vivo imaging device, and the total fluorescence intensity and the fluorescence intensity per unit area were recorded. Figure 8 As shown, MntC101 can effectively help SPF mice and mice pre-infected with S. aureus to eliminate S. aureus.

[0037] The above embodiments are merely preferred embodiments for the purpose of fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

Claims

1. A Staphylococcus aureus MntC protective epitope peptide, characterized in that: The sequence of the epitope peptide is shown in SEQ ID NO.

1.

2. A vaccine based on the Staphylococcus aureus MntC protective epitope peptide according to claim 1, characterized in that: The amino acid sequence of the vaccine is shown in SEQ ID NO.

2.

3. The vaccine of Staphylococcus aureus MntC protective epitope peptide according to claim 2, characterized in that: The nucleotide sequence of the vaccine is shown in SEQ ID NO.

3.

4. The method for preparing the vaccine of the Staphylococcus aureus MntC protective epitope peptide according to claim 2 or 3, characterized in that: The sequence shown in SEQ ID NO.3 was connected to the EcoR I and Xho I restriction sites of the PGEX-6P-2 vector, and then expressed in Escherichia coli and purified.

5. Use of the vaccine comprising the protective epitope peptide of MntC of Staphylococcus aureus according to claim 2 or 3 for efficiently and specifically inducing anti-Loop101 antibodies in SPF mice and mice infected with Staphylococcus aureus.

6. Use of the vaccine comprising the protective epitope peptide of MntC of Staphylococcus aureus according to claim 2 or 3 for protecting against Staphylococcus aureus infection in SPF mice and mice previously infected with Staphylococcus aureus.

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