Formulating a method of determining the efficacy of H.pylori eradication with pulsed field gel electrophoresis

利用分子生物学技术，我们试图确定幽门螺杆菌根除的疗效，研究感染率的变化，并研究幽门螺杆菌毒力因子cagA的流行情况。在研究的第一年，我们比较了幽门螺杆菌对AMPC、CAM、2001年1月至2002年1月间，用LPZ+AMPC+CAM三种药物根除的14例患者，在治疗前和治疗后2-3个月共28例标本中检出MNZ。我们还研究了根除失败的原因，通过基因组分析与脉冲场凝胶电泳（PFGE）。在根除失败的5例病例中，治疗前后的基因型匹配。3例病例在根除前和根除后对所有3种药物均敏感;其余2例病例在治疗前对CAM原发耐药。这些病例不能被认为是由于根除而获得性耐药，因此， 关于我们 在研究的第二年，我们使用HpSA ELISA试剂检测粪便抗原和临床技术人员常规处理幽门螺杆菌的感染状态，检查幽门螺杆菌感染率的变化。关于感染率，与10年前相比，只有个别年龄组的阳性率有所变化。在7名常规处理幽门螺杆菌的技术人员中，2名幽门螺杆菌粪便抗原阳性。与内窥镜医师等医护人员的幽门螺杆菌感染率高达50%以上的报道相反，在从事幽门螺杆菌检测的细菌学技术人员中，没有发现这种现象。第三年，我们用PCR检测了幽门螺杆菌的毒力因子cagA。108株临床分离株中有106株具有cagA ;这与95-100%的临床分离株具有cagA的报告一致。这表明，拥有cagA可能不是幽门螺杆菌发病或预后的指标。少

With a molecular technique, we attempted to determine the efficacy of Helicobacter pylori eradication, study changes in the rate of infection, and study the prevalence of cagA, a virulence factor for H.pylori.In the first year of the study, we compared H.pylori's pattern of sensitivity to the three agents of AMPC, CAM, and MNZ detected before and after eradication in a total of 28 specimens from before and 2-3 months after treatment in 14 cases in which eradication was performed with the three agents of LPZ+AMPC+CAM from January 2001-January 2002. We also studied the causes of eradication failure through genomic analysis with pulsed field gel electrophoresis (PFGE). In 5 cases where eradication failed, the genotypes before and after treatment matched. Three cases were sensitive to all 3 agents before and after eradication ; the remaining 2 cases had primary resistance to CAM before treatment. These cases cannot be considered to have acquired resistance due to eradication, so the cause … More of failed eradication was not development of resistance or re-infection but was because the eradication agents were not taken correctly.In the second year of the study, we examined changes in the rate of H.pylori infection using an HpSA ELISA reagent for fecal antigen detection and the state of infection of clinical technicians routinely handling H.pylori. With regard to the rate of infection, there was only a shift in positive rates for individual age groups in comparison to 10 years prior. Of 7 technicians routinely handling H.pylori, 2 were positive for H.pylori fecal antigens. In contrast to a report of a rate of H.pylori infection of 50% or more in health care personnel such as endoscopists, this phenomenon was not noted in bacteriology technicians involved in H.pylori testing.In the third year, we examined cagA, a virulence factor for H.pylori, with PCR. One hundred and six of 108 clinically isolates possessed cagA ; this agreed with a report of 95-100% of clinically isolates possessing cagA. This suggests that possession of cagA may not serve as an indicator for onset by H.pylori or prognosis. Less