Study On Bacteriostatic Action And Antimicrobial Mechanism Of Pyrolin Against Staphylococcus Aureus

For studying on bacteriostatic action and antimicrobial mechanism of Pyrolin against Staphylococcus aureus, by using the common experimental way in microbiology, Mensuration of conductivity meter, scanning electron microscope, RT-PCR and so on, Staphylococcus aureus were studied in the growth curves, the membrance patency, the structure under scanning electron microscope and mRNA level of femB gene and so on, who is normal and effected by different Pyrolin who is main actival composition in Pyrolaceae. The results show that Pyrolin could inhibit the growth of Staphylococcus aureus, and the minimum inhibitory concentration was 0.16mg/ml. Pyrolin had strong bactericidal action against Staphylococcus aureus, and the minimum bactericidal concentration was 0.2mg/ml. The membrance patency of the cells affected by Pyrolin sharply increased compared with that of the normal cells. Observation under scanning electron microscope revealed that structure of the cells of Staphylococcus aureus had been significantly destroyed by Pyrolin, and the cells wall were melted. The cells were stick by the melt together, and the bounds among cells got blur. They indicated that the antimicrobial activity and the bactericidal function of Pyrolin against Staphylococcus aureus were directly relevant to the structure destruction of cells membrance and wall. RT-PCR of femB gene show that the mRNA level of Staphylococcus aureus femB gene gradually reduced with the extending of the affected time by Pyrolin. When Staphylococcus aureus were affected by Pyrolin for 8 hours, femB gene translation level of Staphylococcus aureus already had decreased to the 1/4 than that of normal cells. It revealed that the transcription from femB gene to mRNA was inhibited, and the quantities of translation and expression of femB enzyme decreased. In summary, the normal synthetic process of the bacterial cells walls was inhibited.