Study On The Bacteriostatic Action And Mechanism Of The Aqueous Extract Of Herba Pyrolae On Enterococcus Faecalis

In order to dealing with the increasingly serious threaten cause by bacterial drug resistance,this article focus on the research of new antimicrobials for the enterococcus faecalis.The bacterias was isolated and identificated from pig die of illness and the Herba Pyrolae was screen out by the in vitro bacteriostatic experiment.The antibacterial mechanisms were.studied primarily and the results could be the primary bases for the further research.The strains used in this study were cultured in indicator culture-medium and identified by Gram stain microscopy and PCR amplification of 16S rRNA,and their drug susceptibility to common antibiotics were determined by the double microbroth dilution method.Fourteen kinds of traditional Chinese medicine aqueous extracts were screened,and their inhibitory effects on Enterococcus faecalis and Escherichia coli as well as the combined effects of Chinese and antibiotics were test through drug susceptibility test and trace board dilution methods,and joint induction and passage methods.The model of fecal enterococcus infected root canal was developed and be used to test the antibacterial effect of aqueous extract of Herba Pyrolae;the growth curve was drawn,the extracellular nucleotide concentration was measured and observed,the ultrastructural changes under transmission electron microscopy,the relative membrane potential changes of the bacteria,and the proportion of apoptosis after dosing.Change,SDS-PAGE gel electrophoresis observed changes in total protein caused by the addition of drugs,to speculate the antibacterial mechanism of Haloxylon stratum,the results are as follows:1.The strains were identified as Enterococcus faecalis and Escherichia coli.The susceptibility results showed that Enterococcus faecalis had different degrees of resistance to 20 antibiotics.Among them,Enterococcus faecalis was resistant to lincomycin,azithromycin,ceftazidime,cefotaxime,and cephalosporin.Thiofloxacin is extremely resistant;E.coli is resistant to ceftriaxone,amoxicillin,fosfomycin,sulfamonomethoxine,and ceftiofur sodium.2.Among the 14 kinds of aqueous extracts of herbs,the antibacterial effect of Herba Pyrolae was the most significant.The minimum inhibitory concentrations against E.faecalis and E.coli were 2.39 mg/ml and 19.13 mg/ml,respectively.When used together with various antibiotics,it can produce synergistic and additive effects with most antibiotics.3.Adding the aqueous extract of Herba Pyrolae can significantly kill the live enterococcus faecalis in the root canal(p<0.001),and the effect is significant.4.In the in vitro antibacterial mechanism experiment,it was found that aqueous extract of Herba Pyrolae can hinder the normal growth of bacteria,and even produce different degrees of killing effect which can destroy the bacterial membrane structure,cause abnormal changes in membrane potential and permeability,resulting in leakage of the contents,and finally Causes the destruction of bacterial cell structure,disintegration of death and apoptosis.On the other hand,through analysis of SDS-PAGE pattern of total bacterial proteins and analysis of protein gel strips,it was found that aqueous extract of Herba Pyrolae can inhibit the synthesis of bacterial protein,especially inhibiting the synthesis of various enzymes in the metabolic process,thus enabling bacterial metabolism.Disturbance,further exert antibacterial effect.