Short-chain antibacterial peptide with anti-Candida albicans activity and application thereof

Abstract

The invention provides a short-chain antibacterial peptide with anti-Candida albicans activity and application of the short-chain antibacterial peptide. The antibacterial peptide is a derivative peptide Pm-2W modified from an antibacterial peptide obtained from Hainan ubiquitous frog. Belongs to the field of application of peptide antibiotics. Antibacterial peptide is modified to obtain the derivative peptide Pm-2W; the Pm-2W disclosed by the invention has efficient activity of resisting candida albicans; the Pm-2W has anti-Candida albicans biofilm activity, is not easy to induce drug resistance, has high stability and low hemolytic toxicity, can be applied to preparation of drugs or bacteriostatic agents for treating Candida albicans infection and the like, and has a good application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of application of peptide antibiotics, in particular to a short-chain antimicrobial peptide with anti-Candida albicans activity and application thereof. Background Art

[0002] Due to the misuse of antifungal drugs, hospital transmission, and large-scale use of fungicides in agriculture, pathogenic fungi are rapidly developing resistance to antifungal drugs. Currently available drugs for the treatment of fungal infections include azoles (fluconazole), echinocandins (caspofungin), and polyenes (amphotericin B). However, due to their strong cytotoxicity, they must be administered at low doses during treatment, which not only leads to reduced antifungal efficacy but also increases fungal resistance. Resistant fungi have been isolated from many patients with fungal infections (Blackman LD, Sutherland TD, De Barro PJ, et al. Addressing a future pandemic: how can non-biological complex drugsprepare us for antimicrobial resistance threats?. Mater Horiz . 2022; 9(8):2076-2096).

[0003] Candida albicans ( Candida albicans ) can cause superficial and systemic infections, colonizing a variety of mucosal sites including the oral cavity, gastrointestinal tract, and urogenital tract in symptomatic immunocompromised patients. C. albicans can transform its morphology from a commensal budding yeast to a pathogenic filamentous form with the ability to damage host cells by triggering cell surface adhesion and invasion. If localized infections are not treated promptly or inadequately, they can spread through the bloodstream, leading to systemic infections with high mortality (Riera FO, Caeiro JP, Angiolini SC, et al. Invasive Candidiasis: Update and Current Challenges in the Management of This Mycosis in South America. Antibiotics (Basel) . 2022; 11(7): 877).

[0004] Antimicrobial peptides (AMPs) are promising antifungal drug candidates with broad-spectrum antimicrobial activity and low drug resistance. A large number of studies have shown that antimicrobial peptides have significant advantages over traditional antibiotics, and their clinical potential is rapidly attracting attention. Most antimicrobial peptides do not have specific molecular targets. They act on the cell membrane, causing cell lysis and death by membrane rupture or changing membrane permeability, and are therefore considered to be a new alternative to synthetic antibiotics (Li R, Wang X, Yin K, et al. Fatty acid modification of antimicrobial peptide CGA-N9 and the combats against Candida albicans infection. Biochem Pharmacol .2023; 211: 115535). Summary of the invention

[0005] In view of the above-mentioned technical deficiencies, the object of the present invention is to provide a short-chain antimicrobial peptide and its application. The Pm-2W of the present invention has high efficiency in anti-Candida albicans activity; Pm-2W has anti-Candida albicans biofilm activity, high stability, low resistance to drug resistance and low hemolytic toxicity, so that it has good application prospects in the treatment of Candida albicans infection diseases.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A short-chain antimicrobial peptide Pm-2W, characterized in that the amino acid sequence of the antimicrobial peptide is as shown in SEQ ID NO: 1, specifically H-Arg-Lys-Ile-Leu-Arg-Pro-Trp-Trp-Trp-NH2.

[0008] Preferably, the antimicrobial peptide has a broad-spectrum antimicrobial activity.

[0009] Preferably, the antimicrobial peptide has the activity of inhibiting the hyphae growth of Candida albicans and anti-biofilm.

[0010] Preferably, the antimicrobial peptide has high stability, is not prone to inducing drug resistance, and has low hemolytic toxicity.

[0011] Preferably, the antimicrobial peptide is used in the treatment of Candida albicans infection.

[0012] Preferably, the present invention provides a pharmaceutical composition, characterized in that the active ingredient contains the above-mentioned antimicrobial peptide.

[0013] Preferably, the present invention provides an antibacterial additive, characterized in that the active ingredient contains the above-mentioned antimicrobial peptide.

[0014] The beneficial effects of the present invention are: the Pm-2W of the present invention has a highly effective anti-Candida albicans activity; the anti-Candida albicans biofilm activity, high stability, low resistance to drug induction and low hemolytic toxicity of Pm-2W make it a promising new antibacterial candidate drug for treating Candida albicans infection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 is the growth inhibition curve of the antimicrobial peptide Pm-2W on Candida albicans ( Figure 1 A) Bactericidal kinetics ( Figure 1 B) Induction of drug resistance in vitro ( Figure 1 C) and cell membrane integrity ( Figure 1 D).

[0017] Figure 2 Scanning electron microscopy was used to observe the effect of the antimicrobial peptide Pm-2W on the morphology of Candida albicans. A: negative control without antimicrobial peptide treatment, B: antimicrobial peptide Pm-2W treatment group.

[0018] Figure 3 The ability of the antimicrobial peptide Pm-2W to inhibit mycelial growth.

[0019] Figure 4 The antimicrobial peptide Pm-2W is used to test its ability to inhibit Candida albicans biofilm. A: inhibits biofilm formation. B: destroys mature biofilm. * represents the difference between the negative control group and the control group without antimicrobial peptide treatment. * P <0.05,** P <0.01,*** P <0.001.

[0020] Figure 5 is the cytotoxicity of the antimicrobial peptide Pm-2W, * represents the comparison with the negative control without antimicrobial peptide treatment, * P <0.05,** P <0.01,*** P <0.001.

[0021] Figure 6is the hemolytic toxicity of the antimicrobial peptide Pm-2W, * represents the comparison with the negative control without antimicrobial peptide treatment, * P <0.05,** P <0.01,*** P <0.001. DETAILED DESCRIPTION

[0022] In order to explain the present invention more clearly, the present invention is further described in detail below in conjunction with embodiments and with reference to the accompanying drawings. It should be understood by those skilled in the art that the content described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0023] The implementation of the present invention mainly includes the following steps:

[0024] 1. The antimicrobial peptide extracted from Pan. punctata was used as a template to design derivative peptides. The DBAASP and APD3 databases were used to analyze the physicochemical properties of the peptides to assist in the design of a derivative peptide Pm-2W with stronger antimicrobial activity, the amino acid sequence of which is shown in SEQ ID NO: 1.

[0025] 2. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined, and the results showed that the antimicrobial peptide Pm-2W has a broad-spectrum antimicrobial activity.

[0026] 3. The results of fluorescence spectroscopy and scanning electron microscopy showed that the antimicrobial peptide Pm-2W can destroy the cell membrane integrity of Candida albicans, thereby achieving a bactericidal effect.

[0027] 4. The results of 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) test and microscopic observation showed that the antimicrobial peptide Pm-2W has the ability to inhibit the growth of Candida albicans hyphae and has anti-biofilm activity.

[0028] 5. The stability experiment, induced drug resistance experiment and hemolytic toxicity experiment showed that the antimicrobial peptide Pm-2W has high stability, is not easy to induce drug resistance and has low hemolytic toxicity, and has application prospects in the treatment of Candida albicans infection.

[0029] Example 1 Design, synthesis and physicochemical property analysis of antimicrobial peptides

[0030] In the early stage, we extracted antimicrobial peptides from Pan tree frogs with spotted legs by cDNA library construction method, and used it as a template to design derivative peptides. The physicochemical properties of the peptides were analyzed using DBAASP and APD3 databases to assist in the design of derivative peptides with stronger antibacterial activity. The amino acid sequence of Pm-2W is shown in SEQ ID NO: 1, specifically H-Arg-Lys-Ile-Leu-Arg-Pro-Trp-Trp-Trp-NH2. It was synthesized by N-9-fluorenylmethoxycarbonyl (Fmoc) solid phase synthesis method, amidation modification of the C-terminus, and purification by reversed-phase high performance liquid chromatography with a purity of ≥95%. The antimicrobial peptide was identified by electrospray mass spectrometry. Its physicochemical properties are shown in Table 1.

[0031] Table 1 Sequence and physicochemical properties of antimicrobial peptide Pm-2W

[0032] Antimicrobial peptides Amino acid sequence MW AI Charge pI BI GRAVY Pm-2W RKILRPWWW 1339.64 86.67 +3 12.01 2.06 -0.989

[0033] Note: MW: molecular weight; AI: Aliphatic index; Charge: charge number; pI: isoelectric point; BI: Boman index, Boman index, indicating the binding ability of protein; GRAVY: hydrophilicity.

[0034] Example 2 Determination of Minimum Inhibitory Concentration and Minimum Bactericidal Concentration

[0035] The antimicrobial peptide solution with a concentration gradient of 0.4-800 μM was prepared by the two-fold dilution method. 50 μL of the above solution was placed in a 96-well cell culture plate, and an equal volume of bacterial solution was added to each well to make the final concentration of the bacterial solution 1×10 6 CFU / mL. The positive control was a bacterial solution without antimicrobial peptides, and the negative control was a solution without either bacterial solution or antimicrobial peptides. After constant temperature culture at 37 °C for 16-24 hours, the lowest concentration of peptide without turbidity at the bottom of the well was observed with the naked eye, and the minimum inhibitory concentration (MIC) was taken. The culture with a concentration of MIC or above was plated, and the lowest concentration of peptide without colony growth was taken as the minimum bactericidal concentration (MBC) after overnight culture. The MIC and MBC of the antimicrobial peptide Pm-2W against methicillin-resistant Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans are shown in Table 2. The peptide has good antibacterial activity against Gram-positive bacteria, Gram-negative bacteria and fungi.

[0036] Table 2 MIC and MBC (μM) of antimicrobial peptide Pm-2W against tested strains

[0037] Antimicrobial peptides Amino acid sequence MRSA CA-1 CA-2 Pm-2W RKILRPWWW 50 / 100 50 / 50 50 / 100 200 / 200 200 / 200 200 / 200

[0038] Note: MRSA: methicillin-resistant Staphylococcus aureus (ATCC 43300); E. coli : Escherichia coli (ATCC25922); P. aeruginosa : Pseudomonas aeruginosa (ATCC 27853); C. albicans : Candida albicans (ATCC10231); CA-1 and CA-2: clinically isolated Candida albicans.

[0039] Example 3 Stability Study

[0040] 1. Effect of temperature on the activity of antimicrobial peptides

[0041] The samples were incubated at 40°C, 70°C and 100°C for 30 minutes to determine the MIC of the antimicrobial peptide against Candida albicans. The untreated samples were used as negative controls. As shown in Table 3, after treatment at different temperatures, the MIC value of the antimicrobial peptide Pm-2W remained unchanged, demonstrating that it has good thermal stability.

[0042] Table 3 Effect of temperature on the activity of antimicrobial peptides MIC (μM)

[0043] Antimicrobial peptides Room temperature 40℃ 70℃ 100℃ Pm-2W 200 200 200 200

[0044] 2. Effect of pH on the activity of antimicrobial peptides

[0045] SDB liquid culture medium with pH values ​​of 5, 7, and 9 was prepared. The MIC of the sample against Candida albicans was determined using this culture medium. The wells treated with SDB liquid culture medium with pH value of 5.6 were used as negative controls. As shown in Table 4, under different pH environments, the antimicrobial peptide Pm-2W was able to maintain its original antibacterial activity, indicating that it has good acid-base tolerance.

[0046] Table 4 Effect of pH on the activity of antimicrobial peptides MIC (μM)

[0047] Antimicrobial peptides Negative control pH 5 pH 7 pH 9 Pm-2W 200 200 200 200

[0048] 3. Effect of serum on the activity of antimicrobial peptides

[0049] SDB liquid culture medium containing 2%, 5% and 10% fetal bovine serum was prepared. The MIC of the sample against Candida albicans was determined using this culture medium. The wells not treated with the sample were used as negative controls. As shown in Table 5, in the presence of serum, the MIC value of the antimicrobial peptide Pm-2W remained unchanged and did not lose its antimicrobial activity, indicating that the peptide has good stability in the presence of serum.

[0050] Table 5 Effect of different serum concentrations on the activity of antimicrobial peptides MIC (μM)

[0051] Antimicrobial peptides 0 2% serum 5% serum 10% serum Pm-2W 200 200 200 200

[0052] Example 4 Growth inhibition curve

[0053] The antimicrobial peptide solution with a concentration gradient of 1 / 8-1×MIC was prepared by the two-fold dilution method. 50 μL of the above solution was placed in a 96-well cell culture plate, and an equal volume of bacterial solution was added to each well to make the final concentration of the bacterial solution 1×10 6 CFU / mL. The positive control was a bacterial solution without antimicrobial peptides, and the negative control was a solution without bacterial solution or antimicrobial peptides. The cells were cultured at 37°C for 24 hours, and the OD 600 was measured at 1 hour intervals using a microplate reader to plot a growth inhibition curve. Figure 1 As shown in A, the antimicrobial peptide Pm-2W can completely inhibit the growth of Candida albicans within 24 hours at a concentration of 200 μM, and can delay the growth of Candida albicans for 12 hours at a concentration of 100 μM, which proves that the peptide has good antibacterial activity.

[0054] Example 5 Bactericidal kinetics

[0055] Cultivate Candida albicans to the logarithmic growth phase and adjust the bacterial solution to a concentration of 2×10 6 CFU / mL for later use. Dilute the antimicrobial peptide using the two-fold dilution method in a 5 mL centrifuge tube. Add 1 mL of diluted bacterial suspension to each tube so that the final concentration of the peptide is 1 / 2-4×MIC. Incubate at 37°C, collect samples at 0, 15, 30, 60, 90, 120 and 180 minutes, dilute with PBS to the appropriate concentration, take 50 μL to spread on agar plates, incubate at 37°C for 24 hours, and count the number of colonies. SDB without peptide is a negative control. Plot the relationship between lgCFU / mL and time to construct a bactericidal curve. Figure 1 As shown in Figure B, the antimicrobial peptide Pm-2W can completely kill Candida albicans within 60 minutes at a concentration of 400 μM, and can completely kill Candida albicans within 120 minutes at a concentration of 1×MIC, i.e., 200 μM, which proves that the peptide has good bactericidal activity.

[0056] Example 6 In vitro drug resistance induction test

[0057] Inoculate the Candida albicans in the logarithmic growth phase into SDB medium containing 1 / 2×MIC antimicrobial peptide, shake culture at 37°C for 24 hours, take an appropriate amount of bacterial liquid and inoculate it into fresh SDB medium containing 1 / 2×MIC antimicrobial peptide, and repeat the subculture for 30 days under the above conditions. Determine the MIC of antimicrobial peptide against Candida albicans every 5 days. Use amphotericin B and ciclopirox as positive controls, and medium without antimicrobial peptide as negative control. Figure 1As shown in Figure C, on the 10th day, the MIC value of amphotericin B against Candida albicans increased by 8 times, from 0.4μM to 3.2μM. On the 20th day, the MIC value of ciclopirox olamine against Candida albicans increased by 4 times, from 25μM to 100μM, indicating that the sensitivity of Candida albicans to amphotericin B and ciclopirox olamine decreased rapidly, resulting in drug resistance. The MIC value of the antimicrobial peptide Pm-2W against Candida albicans remained unchanged within 30 days, indicating that Pm-2W is not easy to develop drug resistance against Candida albicans. On the 30th day, strains resistant to amphotericin B and ciclopirox olamine were isolated, and the MIC value of Pm-2W against them was determined. The results are shown in Table 6. The antibacterial activity of Pm-2W against resistant strains was no different from that against sensitive strains, and its MIC value was still 200μM, indicating that Pm-2W can effectively kill resistant Candida albicans.

[0058] Table 6 Effect of antimicrobial peptide Pm-2W on drug-resistant bacteria C. albicans Strain TypeMIC (μM)

[0059] Antimicrobial peptides ATCC 10231 Amphotericin B-resistant strains Ciclopirox-resistant strains Pm-2W 200 200 200

[0060] Example 7 Detection of Candida albicans Cell Integrity by Fluorescence Spectroscopy

[0061] Prepare peptide solutions with a final concentration of 1 / 2-4×MIC in a 96-well plate. Add propidium iodide (PI) at a final concentration of 50 μM and 1×10 8 CFU / mL Candida albicans. The bacterial solution not treated with peptide was used as a negative control. The cells were cultured continuously at 37°C for 2 hours and the fluorescence intensity was measured every 5 minutes using a multifunctional microplate reader. The excitation and emission wavelengths were 584 nm and 620 nm, respectively. Figure 1 As shown in D, the PI fluorescence of the Pm-2W treatment group increased in a concentration-dependent and time-dependent manner at high concentrations. The results showed that the antimicrobial peptide Pm-2W could destroy the integrity of the Candida albicans cell membrane.

[0062] Example 8 Scanning electron microscopy observation of the effect of antimicrobial peptide Pm-2W on the morphology of Candida albicans

[0063] Resuspend the Candida albicans culture in the logarithmic growth phase to a concentration of 2×10 8 CFU / mL, the bacterial solution and the antimicrobial peptide (final concentration of 4×MIC) were mixed in a volume ratio of 1:1 and incubated for 4 hours. The bacterial solution not treated with peptide was used as a negative control. The bacteria were collected by centrifugation and washed three times, and fixed with 2.5% glutaraldehyde at 4°C for 4 hours. The bacteria were collected by centrifugation and washed three times. The samples were dehydrated with 30%, 45%, 60%, 75%, 90% and 100% ethanol for 10 minutes in turn, and the bacteria were dropped onto tin foil, freeze-dried overnight, vacuum high-pressure gold sprayed, and the morphology of the bacteria was observed by scanning electron microscopy. Figure 2 As shown in the figure, the surface of Candida albicans in the blank control was smooth. The integrity of the cell membrane in the Pm-2W-treated group was severely damaged, the contents leaked out, the cells shrank, and lost their complete morphology. The results show that the antimicrobial peptide Pm-2W exerts its antibacterial effect by destroying the integrity of the Candida albicans cell membrane.

[0064] Example 9 Observation of the effect of antimicrobial peptide Pm-2W on the morphological transformation of Candida albicans using an inverted microscope

[0065] The Candida albicans in the logarithmic growth phase was diluted to a concentration of 1×10 6 CFU / mL, add peptide solution with a final concentration of 1 / 8-1×MIC, and use SDB medium without antimicrobial peptide as negative control. Incubate at 37℃ for 2 hours or 8 hours, and observe the morphological changes of bacteria in each group under an inverted microscope. Figure 3 As shown, the antimicrobial peptide Pm-2W was able to inhibit the transformation of Candida albicans from yeast morphology to hyphae morphology at a concentration of 100-200 μM, and the effect increased in a concentration-dependent manner.

[0066] Example 10 Detection of anti-biofilm activity using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) method

[0067] 1. Inhibit the formation of biofilm

[0068] The Candida albicans in the logarithmic growth phase was diluted to a concentration of 1×10 6 CFU / mL, peptide solutions with a final concentration of 1 / 8-1×MIC were added, and SDB medium without antimicrobial peptides was used as a negative control. The cells were cultured at 37°C for 24 hours, and the biomass of the biofilm was detected using MTT. Figure 4 As shown in A, Pm-2W inhibited the formation of Candida albicans biofilm in a dose-dependent manner, with an inhibition rate of up to 73.1% at a concentration of 1 / 8×MIC, i.e., 25 μM, and almost completely inhibited the formation of biofilm at a concentration of 200 μM.

[0069] 2. Destroy mature biofilm

[0070] The Candida albicans in the logarithmic growth phase was diluted to a concentration of 1×10 7 CFU / mL, add peptide solution with a final concentration of 1 / 4-4×MIC after 24 hours of constant temperature culture at 37℃, and use SDB medium without antimicrobial peptide as negative control. After 4 hours of constant temperature culture at 37℃, use MTT method to detect the ability of peptide to destroy biofilm. Figure 4As shown in B, Pm-2W destroyed the mature biofilm of Candida albicans in a dose-dependent inhibitory manner, with a clearance rate as high as 88.5% at a concentration of 4×MIC.

[0071] Example 11 Cytotoxicity

[0072] Human immortalized keratinocytes (HaCaT) were cultured in DMEM containing 10% fetal bovine serum (FBS), and human umbilical vein endothelial cells (HUVEC) were cultured in DMEM / F12 containing 10% fetal bovine serum (FBS). The above cells were cultured in a 5% CO2, 37°C constant temperature incubator. When the cells grew to 80%, they were enzymatically lysed with trypsin and diluted to 5×10 with culture medium. 4 cells / mL, add 100μL to each well of a 96-well plate, and culture overnight at 37°C and 5% CO2. When the cells grow to 70-80%, remove the supernatant and add 100μL of a two-fold diluted sample of 100μM. The culture medium without the sample is used as a blank control. After incubation for another 4 hours, the culture medium is used to resume overnight. Add 10μL of CCK-8 solution to each well and continue incubation for 2-4 hours. Measure the absorbance at 450nm with an enzyme reader. The calculation formula is cell survival rate = [(OD 实验组 -OD 空白组 ) / (OD 对照组 -OD 空白组 )]×100%. Figure 5 As shown in the figure, at concentrations of 3.1-100 μM, Pm-2W showed no cytotoxicity to HaCaT and HUVEC. At a concentration of 1×MIC, i.e., 200 μM, the cell viability of Pm-2W on HaCaT was 96.6%, and the cell viability on HUVEC was 90.2%. At this concentration, Pm-2W had slight cytotoxicity to HUVEC. The half inhibitory concentration (IC50) of Pm-2W on both cells was greater than 400 μM.

[0073] Example 12 Hemolytic Toxicity

[0074] Mouse red blood cells were washed three times with PBS until the supernatant was clear and diluted to a final concentration of 2×10 8 cells / mL (4%). 300 μL of red blood cell suspension and 300 μL of two-fold diluted sample were mixed, incubated at 37°C for 45 minutes, and 100 μL of supernatant was collected into a new 96-well plate. Each sample was repeated three times and the absorbance was detected at 570 nm. PBS-treated cells were used as negative controls, and 0.1% TritonX-100-treated cells were used as positive controls. Figure 6As shown, the hemolysis rate of mouse red blood cells increased with the increase of the concentration of the antimicrobial peptide Pm-2W, but the hemolysis rate was only 3.23% at a concentration of 1×MIC and only 7.62% at a high concentration of 800 μM, indicating that the antimicrobial peptide Pm-2W had no obvious hemolytic toxicity.

[0075] Obviously, the above embodiments of the present invention are merely examples to more clearly illustrate the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A short-chain antimicrobial peptide Pm-2W, characterized in that: The amino acid sequence of the antimicrobial peptide is shown in SEQ ID NO: 1, specifically H-Arg-Lys-Ile-Leu-Arg-Pro-Trp-Trp-Trp-NH2.

2. The antimicrobial peptide according to claim 1, characterized in that The antimicrobial peptide has a broad-spectrum antimicrobial activity.

3. The antimicrobial peptide according to claim 1, characterized in that The antimicrobial peptide has the activity of inhibiting the growth of Candida albicans hyphae and anti-biofilm.

4. The antimicrobial peptide according to claim 1, characterized in that The antimicrobial peptide has high stability and low hemolytic toxicity.

5. The antimicrobial peptide according to claim 1, characterized in that Application of the antimicrobial peptide in treating Candida albicans infection diseases.

6. According to the use of claim 4, the present invention provides a pharmaceutical composition, characterized in that: The active ingredient contains the antimicrobial peptide according to claim 1.

7. According to the use of claim 4, the present invention provides an antibacterial additive, characterized in that: The active ingredient contains the antimicrobial peptide according to claim 1.

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