The Multilocus Sequence Typing Of Enterococcus Faecium And Indirect Haemagglutination Test For Antibody Detection

Enterococcus faecium(E.faecium) is a major intestinal flora of humans and animals.It is a gram-positive,catalase-negative cocci. In recent years, E.faecium becoming an important opportunistic pathogen of nosocomial infection of gut in human and animal.In china,the study focused on people infected with Enterococcus faecium and isolation,identification of E.faecium strains,it is rarely reported in animals. This thesis aimed to determine the antibiotic resistantance patterns of clinical isolates of enterococci,which can provide the basis for further diagnosis and treatment of enterococcal infections and resistance mechanism and sequence typing study on Enterococcus faecium.In this study, eighteen Enterococcus faecium strain named as LVRI1101, LVRI1102, LVRI1103, LVRI1104, LVRI1301, LVRI1302, LVRI1303, LVRI1304, YYAN1401, YYAN1402, YYAN1403, YYAN1404, lby1,lby2,lby3,lbg1,lbg2, and lbg3 were isolated successfully from lung tissue of the sick goat and pig suffered from a farm located in Gansu,Qinghai province. According to their morphological, physiological and biochemical,and serological characteristics, the strains were identified preliminarily as Enterococcus. The 16 S rRNA gene from the isolate shared 99% homogeneity with that from members of Enterococcus.The result of sequencing showed that the isolate belonged to Enterococcus faecium. Susceptibility test results showed that the isolates were multi-drug resistant strains. The murine assays revealed both E. faecium strain LVRI1101, LVRI1301,YYAN1403 and E. faecium lby1,lbg1 have pathogenicity. Multilocus sequence typing(MLST) based on seven housekeeping genes for E. faecium revealed the 18 isolates belong to three new sequence type, were named as Enterococcus faecium ST989, Enterococcus faecium ST1017, Enterococcus faecium ST1018, and there have been added to the database.At present, in the absence of rapid and effective diagnostic methods at the grassroots level.Sheep red blood cell dealed with glutaraldehyde solution as sensitized by the membrane proteins of Enterococcus,which was extra cted by the methods of ultrasonication to detect the antibody against Enterococcus of goats by indirect haemagglutination test. The method presented good specificity and sensitivity. It provided theoretical basis for the serological diagnosis and epidemiol ogical investigation in this region.