| Objective:1. To construct local Helicobacter pylori(H. pylori) library of high incidence area of gastric cancer in Hexi Corridor through isolating H.pylori from patients with up-gastric symptoms and collecting their associated informations. The library will benefit for further study of its biological characteristics, pathogenicity and pathogenic mechanisms, developping effective vaccines.2. To analysis antibiotics resistance of H.pylori in Hexi Corridor to amoxicillin, clarithromycin, levofloxacin, metronidazole, furazolidone, tetracycline etc in order to provide reference for clinical treatment.3. To investigate H.pylori key virulence gene, vacA and cagA and the relationship between upper digestive tract disease occurrence and genotypes of H.pylori in Hexi Corridor.Methods:1. Collect the cases of314patients with up-gastric symptoms under the aseptic condition in the hospital of wuwei, jinchang and zhangye city and identify them by cultural characteristics, morphology, the rapid urease reaction, the oxidase reaction, catalase test and PCR amplification of ureA. Store the H.pylori under the minus80degrees and summary the patients informations to constuct the H.pylori library.2. The71strains of H.pylori from the library were used to detect the resistance to amoxicillin, clarithromycin, levofloxacin, metronidazole, furazolidone, tetracycline by using Kirby-Bauer disk diffusion method. Compare the difference of the drug resistance of H.pylori in gender, age, pathological type in different patients.3. Extracting70cases DNA gene from H.pylori library, amplificating the primer of s region in gene vacA of H.pylori (s1a,s1b,s1c,s2), m region (m1and m2) in gene vacA and cagA. To compare the relationship between upper digestive tract disease occurrence and genotypes of H.pylori.Results:1. Totally81H.pylori strains were isolated from314patients with positive rates of25.80%. There was no difference in the positive rate between different genders (p>0.05).There existed significant difference in patienis in different age and the pathologieal type group. The positive rates of H.pylori in peptic ulcer patients(46.43%)was significantly higher than that in the chronic gastritis group(23.32%)(P<0.05), so was the15-30year old age group than that in the age group above61years (P<0.05). Positive rates of H.pylori from gastric mucosa cases preserved in liquid nitrogen was higher than that in the temperature of-20℃.Freezed H.pylori strains under the minus80degrees, and constructed H.pylori library in Hexi Corridor successfully.2. The drug resistance of71H.pylori strains to the antimicrobial was as follows, metronidazole(47.89%),levofloxacin(8.45%),amoxicillin(4.23%),tetracycline (2.82%), clarithromycin(1.41%)and furazolidone(0%). There was no significant drug resistance difference between different genders and different ages (P>0.05).The resistance to the levofloxacin from the patients that with chronic gastritis, peptic ulcer and gastric carcinoma was as following:3.85%(2/52),9.09%(1/11)and37.50%(3/8). The levofloxacin resistance in gastric carcinoma was remarkable higher than that in chronic gastritis (P<0.05).There was no significant difference between H.pylori from different pathologieal type patienis and the other antimicrobial(P>0.05).3. The vac A of70H.pylori strains were all positive and sla was57.14%(40/70).There were11sic single-positive strains with positive rates of15.71%. There were19H.pylori strains with sla and slc double positive with positive rate was27.14%(19/70).The positive rate of m2was52.86%(37/70) And no ml positve H.pylori strain was detected. The positive rate of cagA was97.14%(68/70). The genotype of vacAsla and sla/m2were higher than the other genotype of vacA in different pathological type, age, area groups.Conclusion:1. The infection of H.pylori plays an important role in the etiology and progression of peptic ulcer in Hexi Corridor.2.The isolation rate of H.pylori from gastric mucosa cases for long-distance and long-time transportation improved by adding glycerol to nutritional medium, preserving and transporting them in liquid nitrogen.3. The strains library of H.pylori in Hexi Corridor will lay the foundation for further study of H.pylori pathogenesis, genetic evolution, vaccine development.4. Metronidazole should not be used as first-line agent for H.pylori treatment in Hexi area due to the high resistance. Furazolidone and amoxicillin should be used as the first-line to eradicate H.pylori infection.5. The H.pylori isolated from Hexi Corridor mainly is type I, high virulence strains with vacA and cagA positive. Maybe these were reasons that the high prevalence of upper gastrointestinal diseases and stomach cancer in this area. The highest genotype of vacA was sla/m2which followed with slc/m2. The m region of the vac A maybe exsits greater variability. |
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