An Analysis Of Drug Resistance Of Helicobacter Pylori Isolates In Lvliang City Of Shanxi Province And The Mechanism Of Metronidazole And Clarithromycin Resistance

Object:1.To analyse drag resistance of helicobacter pylori isolates from Lvliang city of Shanxi province,and instruct medicine in clinical.2.To analyse the mechanism of metronidazole and clarithromycin resistance,and offer some datas for study in future.Method:1.284 specimens from gastric biopsy mucosa were smeard and inoculated on H.pylori selective medium(Columbia ager base)containing 10%defibred flesh sheep blood.Put the mediums in anaerobic culturing jar,and then input the microaerobic gas (5%O₂,10%CO₂,85%N₂),Culturing the organism at 37℃and 98%humditidy condition for 3-5 days.104 H.pylori strains were identified by Gram stain and biochemical events(contain urease,catalase,oxidase activities),and then H.pylori strains were stored at -80℃.2.81 H.pylori strains of orginal generation grow well that were recovered and subcultured for three times.Disk diffusion test was used to determine the susceptibility of 81 H.pylori clinical strains to antibiotics (metronidazole,clarithromycin,amoxicillin,levofloxacin,furazolidone),and part of H.pylori strains were confirmed by E-test of clarithromycin.3.15 H.pylori strains resistance to metronidazole,10 H.pylori strains sensitive to metronidazole and NCTC11637 were screened and amplificated the segment of rdxA by PCR;6 H.pylori strains resistance to clarithromycin.10 H.pylori strains sensitive to clarithromycin and NCTC11637 were screened and amplificated the segment of 23SrRNA by PCR.4.Part of PCR-products were sequenced,the nucleotide sequences were analyzed by the DNAStar software package and discuss the difference between resistance and sensitive H.pylori strains.Result:1.104 H.pylori strains were cultured from 284 gastric biopsy mucosa specimens,the positive rate of bacteria culture was 36.6%(104/284).2.The rate of H.pylori resistance to metronidazole was 75.3%(61/81);to clarithromycin was 7.4%(6/81);to amoxicillin was 7.4%(6/81);to levofloxacin was 12.4%(10/81);to furazolidone was 8.6%(7/81).3.The DNA homology of rdxA in Mtz^R and Mtz^S was 94.90%±1.17%and 95.13%±0.57%respectively compared with this gene in the standard strain H.pylori26695,P＞0.05.But the aminophenol homology of RdxA in Mtz^R and Mtz^S was 68.67%±14.67%and 91.63%±3.96%respectively compared with RdxA in the standard strain H.pylori 26695,P＜0.05.4.The DNA homology of 23SrRNA in Clr^R and Clr^S was 97.25%±2.22%and 99.00±0.28%respectively compared with this gene in the standard strain H.pyloriU27270,P＞0.05.Conelusion:1.To compared with CO₂ gas incubator(5%～10%CO₂)and anaerobic culturing jar(5%O₂,10%CO₂,85%N₂),we find the latter superior to former,and the latter culture H.pylori clinical strains better.2.The rate of H.pylori resistance to metronidzole was 75.3%;to clarithromycin was 7.4%;to amoxicillin was 7.4%;to levofloxacin was 12.4%;to furazolidone was 8.6%.3.Aminophenol mutation in RdxA caused by mutation of rdxA which was strongly associated with resistance to metronidazole.4.The mutation of A2143C was probably associated with resistance to clarithromycin,and also find the mutation of A2214G,it was not reported in the reference neither in home nor in abroad.