CN102871996B - Antibiotic composition and application thereof - Google Patents

Abstract

The invention provides a novel antibacterial drug composition and its application. The antibacterial drug composition is composed of two components, one is D-amino acid, and the other is antibacterial active drug and/or its derivative. The invention combines D-amino acid with existing antibacterial drugs for the first time, and enhances the antibacterial activity of antibacterial drugs through D-amino acid interfering with bacterial physiological metabolism, and provides a brand-new way to deal with the increasingly serious problem of bacterial drug resistance. Compared with the traditional new drug research and development, the antibacterial pharmaceutical composition and the method of combined medicine provided by the present invention have the advantages of high efficiency, rapidity, low cost, and many optional combinations, and have shown good antibacterial effect in in vitro and in vivo anti-infection research. active.

Description

A kind of antimicrobial composition and application thereof

technical field

The invention belongs to the field of pharmacy, and in particular relates to an antibacterial drug composition and its application.

Background technique

Infectious diseases are common and frequently-occurring diseases that threaten human life and health, and are also one of the important complications and causes of death of multi-organ diseases. The application of anti-infective drugs has greatly reduced the death of infectious diseases. Commonly used anti-infective drugs include β-lactam antibiotics, quinolone antibiotics, and aminoglycoside antibiotics. Its mechanism of action includes inhibiting bacterial cell wall synthesis, inhibiting certain functions of cell membrane, inhibiting protein synthesis, inhibiting nucleic acid synthesis, inhibiting folic acid synthesis, etc.

D-amino acids naturally exist in many organisms and perform specific functions. For example, D-alanine and D-glutamic acid are important components of bacterial cell walls, while D-serine is a neurotransmitter in humans. But usually, the concentration of these relatively rare amino acids in bacteria is very low. However, recent reports have found that various D-amino acids produced by bacteria in the steady state can accumulate up to millimolar levels, suggesting that D-amino acids are related to the physiological state of bacteria.

Biofilm is a large number of bacterial aggregate film-like substances formed by bacteria adhering to the contact surface, secreting polysaccharide matrix, fibrin, lipoprotein, etc., and embedding themselves in it. A variety of bacteria can form biofilms (such as Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, etc.). Bacterial biofilm formation is an important cause of recurrent chronic infections that are difficult to cure and the emergence of bacterial drug resistance. The mechanism mainly includes: decreased permeability to antibiotics; adsorption of antibiotics to inactivate enzymes and inactivation of antibiotics; slowing down of bacterial metabolism, It is in a "subhibernation state", and the sensitivity to antibiotics is reduced (bacteria forming biofilms are more than 1,000 times less sensitive to drugs than bacteria in a free state); evading the clearance of the body's immune system, etc. However, recent studies have found that a nanomolar level of D-amino acid mixture can make the strains such as Bacillus subtilis that form the biofilm return to the free state, thereby restoring the sensitivity of the strain to antibiotics, and based on the fact that many strains can produce D-amino acids, It is speculated that D-amino acids may be a general signal for biofilm dissociation.

Due to the drawbacks in the medication strategy of traditional anti-infective drug therapy and the serious problem of drug abuse, it has had a serious impact on the microecological balance. Gram-positive and multidrug-resistant bacteria such as MRSA (methicillin-resistant Staphylococcus aureus), VRE (vancomycin-resistant enterococci), PRSP (penicillin-resistant Streptococcus pneumoniae) and others emerged under antibiotic selection pressure Drug-resistant Gram-negative bacteria such as Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, etc., and the treatment of drug-resistant bacteria is very difficult, causing a sharp increase in the infection mortality rate, which poses a serious threat to the health of all human beings. threat (Clin Microbiol Rev, 22(4):582-610, 2009).

The situation of bacterial drug resistance in my country is severe, and multidrug-resistant G-bacteria infection is a serious problem. Pseudomonas aeruginosa and Acinetobacter baumannii resistant to carbapenem antibiotics are widely prevalent in clinical practice, and treatment is difficult or even impossible. Medicine can cure it. In the United States, MRSA has become the leading cause of death from infectious diseases, and the global outbreak and prevalence of superbug NDM-1 has attracted global attention. Moreover, bacterial drug resistance genes are often located on movable elements, which accelerates the spread of drug resistance genes among different strains. Therefore, there is an urgent need to strengthen the research and development of drugs against drug-resistant bacteria.

Many drug resistance genes are derived from non-pathogenic bacteria in the environment. The powerful drug resistance system carried by non-pathogenic bacteria contains resistance elements to natural, semi-synthetic and fully synthetic antibiotics. The emergence of drug resistance seems inevitable. In recent decades, few new types of antibiotics have come out, and the combination of antibacterial adjuvants of antibiotics and other bioactive molecules with existing antibiotics provides a new idea for the development of new anti-drug-resistant bacteria drugs.

Contents of the invention

The purpose of the present invention is to provide the application of D-amino acid in enhancing the antibacterial activity of antibacterial drugs.

Another object of the present invention is to provide a novel antibacterial pharmaceutical composition and its application.

Another object of the present invention is to provide the application of D-amino acid in combination with antibacterial drugs in the treatment of infectious diseases.

In order to achieve the purpose of the present invention, an antibacterial drug composition of the present invention is composed of two components, one is D-amino acid, and the other is antibacterial active drug and/or its derivative; wherein, the D- Amino acids are D-alanine, D-serine, D-methionine, D-threonine, D-phenylalanine, D-glutamic acid, D-glutamine, D-proline, D-arginine amino acid, D-lysine, D-cysteine, D-valine, D-leucine, D-isoleucine, D-tryptophan, D-tyrosine, D-day One or more of aspartic acid, D-histidine, D-asparagine, and glycine without DL typing; the antibacterial active drug and/or its derivatives are β-lactam antibiotics , one or more of aminoglycoside antibiotics, quinolone antibiotics, macrolide antibiotics, chloramphenicol antibiotics, glycopeptide antibiotics, or fosfomycin.

The concentration range of D-amino acid in the aforementioned antibacterial drug composition is 0.001mM~10M. The selection of the type and concentration of D-amino acid in the composition is different according to the strain to be used and the type of antibiotic. It is preferred to combine one or more D-amino acids that have a significant impact on the antibiotic’s resistance to a specific strain (the lower the MIC value) medication. The ultimate goal is to obtain a series of D-amino acid antibacterial pharmaceutical compositions that can effectively fight against specific bacterial strains respectively.

The preparation method of aforementioned antibacterial drug composition comprises two kinds, and the first kind is: first with water or suitable solvent (according to D-amino acid, antibacterial active drug) of two kinds of components D-amino acid, antibacterial active drug and/or derivative thereof option) to be prepared as mother solution, and then according to antibacterial drug activity and required D-amino acid concentration to prepare a combined drug solution of the two. The second is: mixing D-amino acid, antibacterial active drug and/or its derivatives in proportion, then adding water or a suitable solvent (selected according to D-amino acid and antibacterial active drug) to directly prepare the combination liquid of the two. For example, the solvents used to dissolve D-leucine, imipenem, erythromycin, and chloramphenicol are 1M hydrochloric acid solution, 0.01M phosphate buffer (pH7.2), 95% ethanol or glacial acetic acid, 95% ethanol.

The present invention also provides the application of the antibacterial drug composition in the preparation of anti-infective drugs.

The antibacterial spectrum of the anti-infection drug is Gram-positive and/or Gram-negative bacteria and their drug-resistant bacteria. Preferably, the Gram-positive bacteria are one or more of: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Enterococcus faecium, Streptococcus pneumoniae, Streptococcus pyogenes and the like.

The Gram-negative bacteria are: Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Proteus mirabilis, Proteus vulgaris, Mormonella morganii, Citriella heterocystis One or more of Citrobacter, Enterobacter cloacae, Enterobacter aerogenes, and Prufidenbacterium regitii. The present invention further provides the application of the combination of D-amino acid and antibacterial drug in the treatment of infectious diseases, including: 1) D-amino acid and antibacterial drug combined drug preparation; or 2) D-amino acid and antibacterial drug in sequence, That is, D-amino acids are given first, and then antibiotics are given; or antibiotics are given first, and then D-amino acids are given.

For the first time, the present invention scientifically and rationally combines D-amino acids with existing antibacterial drugs, and enhances the antibacterial activity of antibacterial drugs by interfering with bacterial physiological metabolism by D-amino acids, providing a solution to the increasingly serious problem of bacterial drug resistance. Brand new way. Compared with the traditional new drug research and development, the antibacterial pharmaceutical composition and the method of combined medicine provided by the present invention have the advantages of high efficiency, rapidity, low cost, and many optional combinations, and have shown good antibacterial effect in in vitro and in vivo anti-infection research. active.

Detailed ways

The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available products.

Example 1 Preparation of D-serine and meropenem combined drug solution

1. Weigh 0.429g of D-serine powder (molecular weight 105.09, purity 98%), dilute to 10ml with sterile water, and filter aseptically to obtain 0.4M mother liquor.

2. Take 0.25ml of 0.4M D-serine mother solution, and dilute to 10ml with sterile water to obtain 10mM D-serine mother solution.

3. Take 0.1ml of 10mM D-serine mother solution, and dilute to 10ml with sterile water to obtain 0.1mM D-serine mother solution.

4. Weigh 57.6 mg of meropenem powder (purity: 99.1%; moisture: 12.4%), dilute to 10 ml with sterile water, and filter aseptically to obtain a 5 mg/mL mother solution.

5. Mix 0.25ml of 0.4M D-serine mother solution and 0.512ml of 5mg/ml meropenem mother solution, and dilute to 10ml with sterile water to obtain a combined drug solution of 10mM D-serine and 256μg/ml meropenem.

6. Mix 0.1ml of 10mM D-serine mother solution and 0.512ml of 5mg/ml meropenem mother solution, and dilute to 10ml with sterile water to obtain a combined drug solution of 0.1mM D-serine and 256μg/ml meropenem.

7. Mix 0.1ml of 0.1mM D-serine mother solution and 0.512ml of 5mg/ml meropenem mother solution, and dilute to 10ml with sterile water to obtain a combined drug solution of 0.001mM D-serine and 256μg/ml meropenem.

Example 2 Preparation of D-serine and meropenem combined drug solution

1. Weigh 3.43g of D-serine powder (molecular weight 105.09, purity 98%).

2. Weigh 115.2 g of meropenem powder (purity: 99.1%; moisture: 12.4%).

3. Mix the two, and dilute to 10ml with sterile water to obtain a combined drug solution of 3.2M D-serine and 10mg/ml meropenem.

The preparation of the antibacterial pharmaceutical composition composed of other D-amino acids and antibacterial active drugs and/or their derivatives is carried out according to the description in Example 1 or Example 2.

Example 3 Study on the anti-methicillin-resistant Staphylococcus aureus (MRSA) activity of D-serine combined with meropenem

1. Take D-serine (purchased from Sigma Company), prepare 0.4M mother solution with sterile water, and filter for later use. Meropenem powder injection (purchased from CSPC Hebei Zhongrun Pharmaceutical Co., Ltd.), prepared as a 5 mg/mL mother solution with sterile water.

2. Meropenem was diluted with MH broth medium containing 0mM, 0.2mM, 2mM and 20mM D-serine in a two-fold concentration gradient, and the concentration range was 64μg/mL-0.03μg/mL. Add the drug solution of each concentration into a sterile 96-well plate in an amount of 100 μL/well. At the same time, a strain growth control without meropenem was set up.

3. MRSA standard strains ATCC 33591, ATCC 43300, N315, and clinical isolates in Beijing 06-3, 06-16, 06-23, 06-37, 08-6, 08-26, 08-32, 08- 36, 08-44, 08-45, 08-48, and 08-50 were inoculated in 1 mL MH broth medium respectively, and cultured overnight at 37°C.

4. Adjust the overnight cultured bacterial solution to 0.5 McFarland turbidity (approximately 1.0×10 ⁸ CFU/mL), and then dilute it according to a 20-fold concentration gradient as the inoculum solution. The inoculation volume is 10 μL/well, and the inoculation concentration is approximately 5.0×10 ⁵ CFU/mL.

5. Wrap the 96-well culture plate properly to prevent excessive evaporation of the liquid, and culture it at 37°C for 16-18h.

6. Take out the 96-well culture plate and observe the results. The minimum antibiotic concentration for sterile growth is the minimum inhibitory concentration (Minimal Inhibitory Concentration, MIC). The results are shown in Table 1.

Table 1D-serine's effect on meropenem's anti-MRSA activity

It can be seen from Table 1 that the combination of 20mM D-serine and meropenem can improve the antibacterial activity of meropenem, and compared with no D-serine, the MIC decreased by more than 32 times. There was no significant difference between the growth control of strains with various concentrations of D-serine and the growth control without D-serine.

Example 4 Anti-Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa activity research of D-methionine combined with meropenem

1. Take D-methionine (purchased from Sigma Company), prepare 0.25M mother solution with sterile water, and filter for later use. Meropenem powder injection (purchased from CSPC Hebei Zhongrun Pharmaceutical Co., Ltd.), prepared as a 5 mg/mL mother solution with sterile water.

2. Dilute meropenem with MH broth medium containing 0mM, 0.2mM, 2mM and 20mM D-methionine, respectively, for two-fold concentration gradient dilution, the concentration range is 8μg/mL-0.004μg/mL. Add the drug solution of each concentration into a sterile 96-well plate in an amount of 100 μL/well. At the same time, a strain growth control without meropenem was set up.

3. Inoculate 1 mL of MH meat with standard strains Klebsiella pneumoniae ATCC 700603, Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC 27853, Pseudomonas aeruginosa PAO1, and clinically isolated strains Klebsiella pneumoniae 7 and Escherichia coli 1515 in Beijing. culture medium at 37°C overnight.

4. Adjust the overnight cultured bacterial solution to 0.5 McFarland turbidity (approximately 1.0×10 ⁸ CFU/mL), and then dilute it according to a 20-fold concentration gradient as the inoculum solution. The inoculation volume is 10 μL/well, and the inoculation concentration is approximately 5.0×10 ⁵ CFU/mL.

5. Wrap the 96-well culture plate properly to prevent excessive evaporation of the liquid, and culture it at 37°C for 16-18h.

6. Take out the 96-well culture plate and observe the results. The minimum antibiotic concentration for sterile growth is the minimum inhibitory concentration (MIC). The results are shown in Table 2.

Table 2D-Effect of methionine on the activity of meropenem against Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa

It can be seen from Table 2 that the combination of 20mM D-methionine and meropenem can improve the antibacterial activity of meropenem, and compared with no D-methionine, the MIC decreased by 4-8 times. There was no significant difference between the growth control of strains with various concentrations of D-methionine and the growth control without D-methionine.

Example 5 Anti-Staphylococcus aureus activity of D-methionine and ampicillin, D-serine and ampicillin and D-threonine and ampicillin in combination

1. Take D-methionine, D-serine, and D-threonine (purchased from Sigma Company), and prepare 0.25M, 0.4M, and 0.4M mother solutions with sterile water, and filter for later use. Ampicillin standard (purchased from China National Institute for the Control of Pharmaceutical and Biological Products), prepared as 5 mg/mL stock solution with sterile water.

2. Dilute ampicillin with MH broth medium containing 0mM, 0.1mM, 10mM D-methionine, D-serine or D-threonine respectively, and the concentration range is 512μg/mL-0.125μg/mL mL. Add the drug solution of each concentration into a sterile 96-well plate in an amount of 100 μL/well. Simultaneously, a strain growth control without ampicillin was established.

3. Inoculate the tested standard strains Staphylococcus aureus ATCC 43300, Staphylococcus aureus N315, and Staphylococcus aureus Mu50 in 1mL MH broth medium respectively, and culture overnight at 37°C.

4. Adjust the overnight cultured bacterial solution to 0.5 McFarland turbidity (approximately 1.0×10 ⁸ CFU/mL), and then dilute it according to a 20-fold concentration gradient as the inoculum solution. The inoculation volume is 10 μL/well, and the inoculation concentration is approximately 5.0×10 ⁵ CFU/mL.

5. Wrap the 96-well culture plate properly to prevent excessive evaporation of the liquid, and culture it at 37°C for 16-18h.

6. Take out the 96-well culture plate and observe the results. The minimum antibiotic concentration for sterile growth is the minimum inhibitory concentration (MIC). The results are shown in Table 3.

The influence of table 3D-methionine, D-serine and D-threonine on ampicillin anti-staphylococcus aureus activity

As can be seen from Table 3, the combination of 10mM D-methionine and ampicillin can improve the antibacterial activity of ampicillin by 2-4 times; the combination of 10mM D-serine and ampicillin can improve the antibacterial activity of ampicillin by 2-4 times ; The combination of 10mM D-threonine and ampicillin can increase the antibacterial activity of ampicillin by 1-2 times. There was no significant difference between the strain growth control of each concentration of D-amino acid and the growth control without D-amino acid.

Example 6 Anti-Enterococcus faecalis and Enterococcus faecium activity of D-methionine, D-serine, D-threonine three D-amino acids combined with meropenem

1. Take D-methionine, D-serine, and D-threonine (purchased from Sigma), and prepare 0.25M, 0.4M, and 0.4M mother solutions with sterile water, and filter them for later use. Meropenem powder injection (purchased from CSPC Hebei Zhongrun Pharmaceutical Co., Ltd.), prepared as a 5 mg/mL mother solution with sterile water.

2. Prepare brain heart infusion broth (BHI) containing 0.2mM, 2mM and 20mM three D-amino acids (D-methionine, D-serine, D-threonine) respectively.

3. Meropenem was diluted with BHI containing three D-amino acids at 0mM, 0.2mM, 2mM and 20mM respectively, and the concentration range was 256μg/mL-0.125μg/mL. Add the drug solution of each concentration into a sterile 96-well plate in an amount of 100 μL/well. At the same time, a strain growth control without meropenem was set up.

4. Inoculate the tested standard strains of Enterococcus faecalis ATCC 51299, Enterococcus faecalis ATCC29212, Enterococcus faecalis ATCC 700802, Enterococcus faecalis ATCC 51575 and Enterococcus faecium ATCC 700221, and clinically isolated strains of Enterococcus faecalis HH22 and Enterococcus faecalis EFL4041 respectively Incubate overnight at 37°C in 1mL Brain Heart Broth Medium.

5. Adjust the overnight cultured bacterial solution to 0.5 McFarland turbidity (approximately 1.0×10 ⁸ CFU/mL), and then dilute it according to a 20-fold concentration gradient as the inoculum solution. The inoculation volume is 10 μL/well, and the inoculation concentration is approximately 5.0×10 ⁵ CFU/mL.

6. Wrap the 96-well culture plate properly to prevent excessive evaporation of the liquid, and culture it at 37°C for 16-18h.

7. Take out the 96-well culture plate and observe the results. The minimum antibiotic concentration for sterile growth is the minimum inhibitory concentration (MIC). The results are shown in Table 4.

Table 4 Anti-Enterococcus faecalis and Enterococcus faecium activity of D-methionine, D-serine, D-threonine three D-amino acids combined with meropenem

It can be seen from Table 4 that the combination of 20 mM D-methionine, D-serine and D-threonine three D-amino acids with meropenem can improve the antibacterial activity of meropenem. Compared with no D-amino acid, MIC decreased 8-32 times. Compared with the growth control without D-amino acid, the strain growth control with various concentrations of D-amino acid had no significant difference except that the culture medium containing 20mM three kinds of D-amino acid had a slight effect on Enterococcus faecalis ATCC 51299.

Example 7 Anti-Enterococcus faecalis and Enterococcus faecium activity of D-methionine, D-serine, D-threonine three D-amino acids in combination with vancomycin

1. Take D-methionine, D-serine, and D-threonine (purchased from Sigma), and prepare 0.25M, 0.4M, and 0.4M mother solutions with sterile water, and filter them for later use. Standard vancomycin (purchased from China National Institute for the Control of Pharmaceutical and Biological Products) was prepared as a 10 mg/mL stock solution with sterile water.

2. Prepare BHI containing 0.2mM, 2mM and 20mM three D-amino acids (D-methionine, D-serine, D-threonine) respectively.

3. The vancomycin was diluted with BHI containing 0mM, 0.2mM, 2mM and 20mM three kinds of D-amino acids respectively, and the concentration range was 256μg/mL-0.125μg/mL. Add the drug solution of each concentration into a sterile 96-well plate in an amount of 100 μL/well. At the same time, the growth control of strains without vancomycin was set up.

4. Inoculate 1 mL of brain with test strains Enterococcus faecalis ATCC 51299, Enterococcus faecalis HH22, Enterococcus faecalis ATCC 29212, Enterococcus faecalis ATCC 700802, Enterococcus faecalis ATCC 51575, Enterococcus faecalis EFL4041 and Enterococcus faecalis ATCC 700221, respectively. Incubate overnight at 37°C in heart broth.

5. Adjust the overnight cultured bacterial solution to 0.5 McFarland turbidity (approximately 1.0×10 ⁸ CFU/mL), and then dilute it according to a 20-fold concentration gradient as the inoculum solution. The inoculation volume is 10 μL/well, and the inoculation concentration is approximately 5.0×10 ⁵ CFU/mL.

6. Wrap the 96-well culture plate properly to prevent excessive evaporation of the liquid, and culture it at 37°C for 16-18h.

7. Take out the 96-well culture plate and observe the results. The minimum antibiotic concentration for sterile growth is the minimum inhibitory concentration (MIC). The results are shown in Table 5.

Anti-Enterococcus faecalis, Enterococcus faecium activity of three D-amino acids of table 5 D-methionine, D-serine, D-threonine combined with vancomycin

As can be seen from Table 5, 20mM D-methionine, D-serine, D-threonine three D-amino acids combined with vancomycin can improve the anti-vancomycin-resistant enterococcus (fecal The activity of Enterococcus ATCC 51299, Enterococcus faecalis ATCC 700802, Enterococcus faecalis ATCC51575, Enterococcus faecalis EFL4041 and Enterococcus faecium ATCC 700221), compared with no D-amino acid, the MIC decreased by 8-16 times. However, there was no significant effect on the activity of vancomycin against non-vancomycin-resistant enterococci (Enterococcus faecalis HH22 and Enterococcus faecalis ATCC 29212) (MIC remained unchanged or decreased by 2 times). Compared with the growth control without D-amino acid, the strain growth control with various concentrations of D-amino acid had no significant difference except that the culture medium containing 20mM three kinds of D-amino acid had a slight effect on Enterococcus faecalis ATCC 51299.

Example 8 Study on the protective effect of D-serine combined with meropenem on mice infected with clinically isolated methicillin-resistant Staphylococcus aureus (MRSA) 08-50

1. Inoculate MRSA strain 08-50 clinically isolated in Beijing into 10 mL of enrichment broth (0.5% MH+2.5% yeast extract, autoclaved), culture at 37°C for 6 hours, and transfer to 10 mL of fresh enrichment meat In the soup, continue to cultivate overnight (16-18h).

2. After diluting the cultured bacterial solution overnight by 100, 1000, 10000 times, use 5% yeast suspension (w/v, used after autoclaving, yeast purchased from Dongguan Sugar Factory Yeast Branch, Guangdong Province) by 1 : The volume ratio of 9 is prepared as bacterial liquid for infection, and diluted 1000, 10000 and 100000 times respectively.

3. Select 100 ICR mice (purchased from Beijing Weitong Lihua Experimental Animal Technology Co., Ltd.), half male and half female, weighing 18-21g, and randomly divide them into 20 groups, with 5 mice in each group (2 females, 3 males or 2 males) 3 females), 0.5mL bacterial solution/intraperitoneally infected mice, in which the infected bacterial solutions diluted 1000, 10000, and 100000 times were used as controls, and the remaining 12 groups were infected with 10000 times diluted bacterial solutions and given different drugs.

4. Take D-serine (purchased from Sigma Company) and meropenem powder injection (purchased from CSPC Hebei Zhongrun Pharmaceutical Co., Ltd.), and prepare combined drug solutions containing different concentrations of D-serine and meropenem with normal saline, As shown in Table 6:

Table 6D-Pharmaceutical formulations for the combination of serine and meropenem

5. The mice were administered once 1h and 6h after intraperitoneal infection, 0.2mL/mouse each time, and the survival number of animals within 7 days was observed. To analyze the curative effect of D-serine combined with meropenem. The results are shown in Table 7,

Table 7D-Therapeutic effect of the combination of serine and meropenem on mice infected with MRSA strain 08-50 (survival rate)

It can be seen from Table 7 that when D-serine is used alone, it has no therapeutic effect on animals infected with MRSA strain 08-50; when meropenem is used alone, the highest animal survival rate is 40%, and when the two are used in combination ≥ 200mM D-serine +10mg/mL meropenem or 400mMD-serine+≥2.5mg/mL meropenem can make the survival rate of animals reach 100%, indicating that the combination of D-serine and meropenem can effectively prevent the intraperitoneal infection of methicillin-resistant Staphylococcus aureus in mice 08-50 has great protection.

Although the present invention has been described in detail with general descriptions and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (4)

1. an antibacterial combination, is characterized in that, is made up of two kinds of components, and one is antimicrobial active medicament, the another kind of D-aminoacid for strengthening described antimicrobial active medicament antibacterial activity; Specifically be made up of D-Ser and meropenem, or be made up of D-methionine and meropenem, or be made up of D-methionine and ampicillin, or be made up of D-Ser and ampicillin, or be made up of D-Thr and ampicillin, or be made up of D-methionine, D-Ser, D-Thr three kinds of D-aminoacid and meropenem, or be made up of D-methionine, D-Ser, D-Thr three kinds of D-aminoacid and vancomycin.

2. antibacterial combination according to claim 1 is preparing the application in anti-infectives, and the antimicrobial spectrum of described anti-infectives is Gram-positive and/or gram negative bacteria and their fastbacteria.

3. application according to claim 2, is characterized in that, described gram-positive bacterium is: one or more in staphylococcus aureus, staphylococcus epidermidis, enterococcus faecalis, enterococcus faecalis, streptococcus pneumoniae, streptococcus pyogenes.

4. application according to claim 2, it is characterized in that, described gram negative bacteria is: one or more in Acinetobacter bauamnnii, klebsiella pneumoniae, escherichia coli, bacillus pyocyaneus, serratia marcescens, proteus mirabilis, proteus vulgaris, Mo Genmo Salmonella, special-shaped citrobacter, enterobacter cloacae, clostridium perfringen, thunder Ji Shi Pu Lufeideng bacillus.