Detection on Biofilm and Biofilm-associated Genes of Enterococcus faecalis Inducing Lamb Encephalitis

The purpose of this study was to observe and analyze the ability of biofilm formation of the Enterococcus faecalis (E.faecalis) XJ05 and to detect if the E.faecalis which could induce lamb encephalitis carried the biofilm-associated genes. The E.faecalis XJ05 was used as the sample. The biofilm model was established by the 96-well microtiter plate and read by microplate reader in the D_{595 nm} at the same time observed by the inverted microscope. The primers were designed to examine if the 11 strains of E.faecalis carried the biofilm related genes and then the amplified products were sequenced and analyzed for homology. The results showed that the amount of BF produce in XJ05 strain was significantly different from blank control group at different time (P<0.05), and the highest D_{595 nm} value was at 24 h and significant difference compared with other time (P<0.05). The biofilm of 6 h was scattered when observed under the microscope and the time between 12 to 24 h biofilm to be more denser, after 24 h the biofilm became to degradate and loose gradually. It turned out that the 11 strains of bacteria carried different biofilm-associated genes, 8 biofilm-associated genes were found in 6 strains of bacteria, 7 biofilm-associated genes were find in 1 strain of bacterium, 6 biofilm-associated genes were found in 1 strain of bacterium, 2 biofilm-associated genes were found in 1 strain of bacterium, 2 strains of bacteria could not text out anyone of the detected genes.The homology of all detected genes were all between 93.3% to 100.0%. It concluded that the E.faecalis XJ05 could form the completed biofilm and there were 9 kinds carried the biofilm-associated genes in 11 strains of E.faecalis.