Function Of Matrine On Biofilm Produced By Staphylococcus Epidermidis

Staphylococcus epidermidis (SE) has been considered as opportunistic pathogen with weakly pathogenic. However, with the development of deeply study on Staphylococcus epidermidis, it was recognized that as a drug-resistant genes storage. And meanwhile, it could form biofilm and other virulence factors. Furthermore, it’s very easily leading to cause the occurrence of dairy mastitis and make the disease recurrent and difficult to cure. Therefore, further understand the effect and mechanism of drug on the epidermidis Staphylococcus biofilm formation, could provide the theoretical basis and technical support for the treatment on the Cow Mastitis caused by Staphylococcus epidermidis.Staphylococcus epidermidis were separated from368clinical positive mastitis milk samples, and the positive biofilm strains were selected by the method of congo red and crystal violet staining. Staphylococcus epidermidis biofilm related genes(icaA、icaR、icaAB、aap、bap、atlE、sigB、agr、 fbe and sarA) were propagate by PCR. The process of Biofilm formation was observed and analysised after the Staphylococcus epidermidis biofilm model was established on plate, The minimal inhibitory concentration (MIC) and Minimum bacteriostatic concentration of biofilm (SMIC) of Matrine, Sophorea Alopecuroides(TASA), Ciprofloxacin and Erythromycin against biofilm strains were determined. The process of the biofilm formation and structural parameters were analysised by the methods of XTT, silver staining, confocal microscopy combined with the image analysis software. in the end, the relative expression quantity of SE biofilm formation related genes(sigB, agr and fbe) in the isolated strains in the pesence of Matrine, Sophorea Alopecuroides, Ciprofloxacin and Erythromycin by using the method of qPCR.The results showed that15strains of Staphylococcus epidermidis which were selected from clinical mastitis milk samples forming biofilm of positive strains rate reached46.7%. The isolated strains had the highest drug resistance to Penicillin, and the drug resistant of biofilm of positive strains was higher than that of negative strains. The biofilm formation related genes liked sigB、agr、 fbe and atlE were amplified in the positive strains. The initially forming of SE biofilm were found at the24h by morphological observing, then it became thicker at48h with the structure being more complex. Matrine and TASA with higher MIC compared to Ciprofloxacin and Erythromycin for planktonic bacteria, but they had better effect for biofilm SMIC50. Matrine and other drugs inhibited earlier biofilm of SE, but with its increasing, the inhibitory effect of Matrine and TASA were superior to Ciprofloxacin and Erythromycin. The Matrine had regulating effects on SE biofilm virulence genes such as sigB, agr and fbe, and with its concentration increasing, agr gene expression with a trend of dropping first then rising, but fbe and sigB gene had opposite results. These results showed that Matrine could inhibit biofilm formation by regulating the related genes.