| Helicobacter pylori is the main pathogenic factor of peptic ulcer and chronic gastritis,which is related to the occurrence of gastric cancer and gastric mucosa associated lymphoid tissue(MALT).Other non-gastrointestinal diseases,such as unexplained iron deficiency anemia and thrombocytopenia purpura,could also develop due to Helicobacter pylori infection.This study successfully isolated 69 strains,positive rate was 23.1%.Specimens according to the patients with pathological diagnosis were divided into 3 groups,include peptic ulcer,Non ulcer dyspepsia and gastric cancer.29 strains were isolated with gastric and duodenal ulcer,29 strains were isolated with Non ulcer dyspepsia group,including duodenitis,superficial gastritis,atrophic gastritis and erosive gastritis and other diseases,11 strains were isolated with gastric cancer.In this study,method of random amplified polymorphism DNA was adopted for H.pylori genome analysis on the separated 69 strains.Results showed that a total of 6 different genotypes were found.9 strains of H pylori has 1 band in peptic ulcer and nonulcerative indigestion,of which 2 ~ 4 bands have the highest proportion,accounting for 75.4%.Patients with gastric cancer mainly had 4 ~ 6 bands,and 6 bands were only found in gastric cancer.There was a correlation between the severity of gastrointestinal disease and the genotypes of RAPD(P<0.05),which provided a reference for the diagnosis and treatment of gastrointestinal diseases in H.pylori infection.AGAR dilution method was used for resistance analysis,seven antibiotics commonly used in clinic were applied in this study.Results showed that 36 strains were resistant to clarithromycin(52.2%).Metronidazole and tinidazole with 21 strains(30.4%)and 33 strains(47.8%)respectively,resistance rate of levofloxacin was 37.7%(26/69),and resistance rate of tetracycline hydrochloride and furazolidone was 33.3%(23/69)and 30.4%(21/69).Amoxicillin had a minimum tolerance rate of 5.8%,which could continueto be used as a first-line antimicrobial agent.There are multidrug resistant strains in the region,17 strains(24.6%)were sensitive to all of the seven antibiotics.Among drug-resistant strains,16 strains(23.2%)were resistant to one antibiotic and 36 strains(52.17%)of the three antibiotics and the multidrug-resistant strains.This provides guidance for clinical use of first-line triad therapy to eradicate infection.Through the analysis of the relationship between gene and drug resistance,there was no correlation between cag A gene and antibiotic resistance,and the distribution difference between the two virulence genes of vac A and ice A in antibiotic resistance and sensitive strain showed that the drug resistance rate of vac A s1 a positive strain to metronidazole was higher(P=0.034).vac A s1 c positive strains were more sensitive to the three antibiotics of metronidazole,clorycin and levofloxacin(P=0.013,P=0.009,P=0.008).vac A m1 a positive strain positive strain was more sensitive to tetracycline hydrochloride(P=0.017),and vac A i1 positive strain was more sensitive to tinidazole(P=0.018).ice A 1 virulence genes in clarithromycin,furazolidone,indications for distribution between the resistant and susceptible strains of statistically significant(P = 0.003,0.042,0.047),namely ice A1 positive for indications of clarithromycin and resistance is higher,and more sensitive to furazolidone.Eight mutation sites were found in a group of clarithromycin resistance sequencing: A1821 G,G1826A,T1830 C,G1940A,C1953 T,A2143G,T2182 C,A 2223 G.A2143G mutations(54.2%)lead to strains of clarithromycin resistance,is the major mutations in the region.In conclusion,the relationship between H.pylori genome polymorphism and digestive system disease was studied,and the antibiotic resistance and drug resistance mechanism were analyzed,which provides a personalized and rationalized treatment for clinical patients so as to eliminate H.pylori infection... |
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