Antimicrobial Activities Of Self-made Enzyme On Methicillin Resistant Staphylococcus Aureus In Vitro

Objective:Methicillin resistant staphylococcus aureus is the most common staphylococcus aureus of drug resistance in hospital.It is very dangerous with multiple drug resistance and high fatality rate. The trends in bacterial resistence is becoming the world’s medical problem. Therefore, to seek new drugs or biologics against the MRS A resistant is a focus of the whole world. Our laboratory finally make 7 kinds of enzyme using fresh fruits, vegetables and medicinal materials through consulting a large number of relevant literature. Antibacterial susceptibility testing was performed using broth microdilution on 7 kinds of enzyme to determine the role of the drug’s dosage.To explore the influence of physical factors on the antibacterial effect with 7 kinds of enzyme,finally to explore the influence of physical factors on laggera pterodonta and chayote enzyme, to determine the dosage of laggera pterodonta and Chayote enzymethese in different growth periods. To laid a solid foundation for MRS A infection, to provide theoretical support for studing the medicinal value of the enzyme.Methods:1.The preparation of the enzymeSelect several Chinese medicine according to reports:laggera pterodonta, alligator alternanthera herb, dodder, artemisia stelleriana. Several vegetables:chayote, carrots, white radish. Cleaning, to make enzyme through consulting a large number of relevant literature, mixing materials, brown sugar and water according to certain proportion, sealing fermentation for months, getting clear yellow liquid, the stoste needs to be filtered twice through the filter of 0.22μm.2.Antibacterial experimentAntibacterial susceptibility testing was performed using broth microdilution according to CLSI procedures, to ensure the minimal inhibitory concentration and the minimal bactericidal concentration according to the standard requirements. 3.The influence of different temperatures and pressures on the two kinds of enzymeComparing the difference between antibacterial effect under different conditions and the temperatures with high pressure steam,low temperature, high temperature.4.Time-kill curvesLaggera pterodonta enzyme, the chayote enzyme. Selection of antimicrobial drug concentration of 2 MBC, MBC,2 MIC, MIC, add bacteria,take out bacteria on 0, 1,2,3,4,5,6,8,10,12,16,24hwith live bacteria counting, drawing bactericidal curve in time for the abscissa, bacteria counting for ordinate.5. The influence of pH on the antibacterial activity of two kinds of enzymeThe physiological saline was used to change pH to be simple with pH of laggera pterodonta enzyme and pH of chayote enzyme respectively. According to the method of time-kill curves, drawing bactericidal curve in time for the abscissa, bacteria counting for ordinate.6.The influence of laggera pterodonta enzyme and the chayote enzyme on different periods of MRS ALiving bacteria counting methodwas used to determine the bacterial growth cycle. In logarithmic phase, stabilization, declintion to add laggera pterodonta enzyme and the chayote enzyme with different concentrations. Selection of antimicrobial drug concentration of 2 MBC, MBC,2 MIC, MIC, add bacteria,take out bacteria on 0,1,2, 3,4,5,6,8,10,12,16,24h with live bacteria counting, drawing bactericidal curve in time for the abscissa, bacteria counting for ordinate.Results:1.The materials of the 7 kinds of enzyme are chayote, laggera pterodonta, alternanthera herb, dodder, artemisia stelleriana, carrots, white radish, the MICs (mg·mL-1) were 37.5,37.5,75,150,75,75,75 respectively, the MBCs (mg·mL-1) were 150,150, NO,300,300,300,300. Screening the beter ones with bacteriostatic effect among 7 kinds of enzyme are laggera pterodonta enzyme and chayote enzyme.2.Comparing the diference between antibacterial effect in high temperature, high temperature (high pressure), low temperature and room temperature. Conclusions:the bacteriostatic effect doesn’t vary under different temperature conditions.3.The two kinds of enzyme have effects in different periods of bacteriostasis on MRSA. The laggera pterodonta enzyme and chayote enzyme have an antibacterial effect (p-value<0.05). Two same pH of enzyme have an inhibition effect (p-value> 0.05),but don’t have an bactericide effect (p-value<0.05). The two kinds of enzymes have different degrees of bacteriostasis effects on MRS A in different periods, especially on exponential phase.Conclusions:1.7 kinds of enzyme have certain bacteriostasis effects on MRSA,the effect shows a significantly dose-dependence. Concentrating enzyme is a prospective direction.2.Concluding that in different temperatures and pressures the effects are changeless, speculating that enzymes can be stored in different temperature conditions, the substance of antibacteria are not protein but are very stable.3.The antibacterial effects of the laggera pterodonta enzyme and chayote enzyme are not better than positive medicine-Linezolid, the effect has a certain correlation with pH value, substance of antibacteria don’t change in the acidic conditions. The two kinds of enzymes are breeding season antiseptic, mechanism is disturbing replication of bacteria.