Establishment Of PCR For E.Coli O157: H7 And Preliminary Application

Escherichia coli O157:H7 is one species of highly harmful food-borne disease-caused bacteria, causes severe hemorrhagic colitis and the life-threatening extraintestinal complication of hemolytic uremic syndrome(HUS) in 5 to 10%of patients.EHEC O157:H7,produce Shiga like toxin 1 or 2(Stx1 or Stx2,respectively),or both.The source of EHEC O157:H7 is mainly of contaminated food or drinking water.Treatment of infection with EHEC O157:H7 has been difficult because antibiotics do not change the course of the enteritis of EHEC O157:H7 and may increase the incidence of HUS caused by the pathogen.This untoward effect has been proposed to be mediated by antibiotic-induced bacteriolysis and release of intracellular Shiga like toxins.Has this article carried on the microorganism appraisal to it,whether there is qualitative and Polymerase chain reaction(PCR) as well as the utilization multiple PCR reacting system examines Changchun area meat egg milk market this fungus the research.Firstly,microbiologic incubation and detection had been carried out to understand the fundamental biologic characters of E.coli 0157:H7 and to elementarily identify it by using SMAC culture medium.Next,designs 3 pairs in view of its specificity pathogenesis gene stx1,stx2 and specificity flagella gene flic to direct the thing,establishes the multiple PCR reacting system,carries on the PCR examination,finally indicated that 3 pairs direct the thing to be possible to increase effectively and to have the good specificity.Through the optimized experiment determined that its most suitable annealing temperature for 57℃,responds directs the density is 1umol/l,DNA3ul best.,and 6 hours may examine the sample whether do include O157:H7.Third,through already the multiple PCR reacting system which establishes,examines Changchun area spring,whether there is summer two Ji Roudan the milk market backwoods coli O157:H7 existence,and discovers on this fungus's characteristic avoids polluting food the method and the prevention and control measure.