|
Staphylococcus aureus is a human and animal infections and food poisoning common pathogens, more and more serious with the extensive use of antibiotics resistance of Staphylococcus aureus, penicillin-resistant strains have appeared, methicillin-resistant drug strains of vancomycin-resistant strains. The same time, with the resistant group continues to expand, the multi-drug resistant strains have emerged, and the treatment of infections caused by Staphylococcus aureus has become a thorny issue. Staphylococcus aureus virulence size of its virulence factor production related, therefore, to find a drug to reduce the virulence factor production is important for the treatment of diseases caused by Staphylococcus aureus. MIC (Minimal Inhibitory Concentration) was determined by double dilution method determination of cinnamic aldehyde MIC ATCC (American Type Culture Collection) 29213 and six clinical isolates of Staphylococcus aureus. The cinnamic aldehyde Staphylococcus aureus MIC 128mg/l-256mg/l. Bacteriostatic curve drawing ATCC 29213 Determination of bacterial growth curve in the bacterial growth to an OD600 of 0.3, cinnamic aldehyde, to which was added to a final concentration of 256mg / l, 128mg / l, 64 mg / L, 32mg / L, 16mg / L 0mg / l, measured every 15min OD600, a bacterial growth curve. The results show only 256mg / L and 128mg / l of the concentration of cinnamic aldehyde could significantly inhibit the growth of bacteria, the inhibition of other groups is weak. The immunoblot detected using ATCC 29213 and clinical isolates SA3629, culture above (minus the 256mg / l group), collected in OD600 2.5 broth, separation of bacteria and supernatant total protein content in the supernatant was measured Western blot. The results show that, 128mg / l and 64mg / l of the concentration of cinnamic aldehyde can significantly reduce the alpha-hemolysin, and enterotoxin A, the yield of B, the other groups are also able to reduce its yield. The detection of of Hla and agrA gene using real-time quantitative PCR method to detect the expression of these two genes cinnamon aldehyde treatment changes. The results show that: the hla and agrA of expression of four sub-inhibitory concentration group were less than the control group, in a concentration-dependent manner. Hla expression levels of 128mg / l group only control group, 6.33% the expression of agrA only 12.11% of the control group, and expression of hla and agrA of change is not exactly the same amount of difference. Cinnamic aldehyde is possible to suppress the results of this study table Minya inhibitory concentration of Staphylococcus aureus alpha-hemolysin, enterotoxin A and B production, its inhibition mechanism is likely to be accomplished through regulation of agr dual-control regulation system 's.
|