| Objective:To analyze the drug-resisitance of HP strains achecied from patients with gastic diseases to different antibiotics by selecting the antibiotics-resistant strains and amplifing and sequencing the fragments of HP resistance gene in Jilin Province. And discuss the mechanism of drug-resistant.Methods:84 HP strains were achieved from patients and tested drug sensitive test to metronidazole, clarithromycin and amoxicillin by E-test to select the drug-resistant HP strains whose resistant gene fragments were amplified and sequenced.At the same time, HP standard strains,HP11637 and HPSS1,were tested antibiotics induced resistance in vitro. Then sequence the resistant gene of HP strains which appeared antibiotics-induced-resistant to metronidazole, clarithromycin and amoxicillin. And analyze mechanisms by which HP strains appeared antibiotics-resistant.Results:84 HP strains were acheived from patients and tested drug sensitive to metronidazole, clarithromycin and amoxicillin by E-test.The resistant rates were separately 67.9%(57/84),17.9%(15/84) and 1.2% (1/84),in which 10 strains showed mixed drug resistant to metronidazole and clarithromycin, and 1 HP strain was mixed-resistant to metronidazole, clarithromycin and amoxicillin. HPSS1 and HP11637 strains were only introduced resistance to metronidazole in vitro. By comparing rdxA DNA sequence 7296-7815 of metronidazole resistant HP strains with the relative sequence of standard HP26695 strain,we found 68 mutation sites in rdxA and the mutations were lack of significant law,in which there were no obvious mutation hot spots.And by comparing with foreign literatures,there were no new mutation site. Collect and purify the amplified product by PCR and sequence it.Compare 23S rRNA sequence 2106-2320 of clarithromycin resistant HP strains with the corresponding sequences of standard strains HP26695. The results showed that 2144 site is one of the hot mutants in the clarithromycin resistance mutations.The mutantions were mostly in the form of base substitution,and fewer insertions and deletions happened. A→G in 2144 site was most frequent, which was found in seven HP strains, in three HP strains mutation C→T happened in 2289 site, T insertion in 2267 site happened in two HP strains.Compare with the forgein literatures and no new mutations sites were found in this study. By comparing pbp1A gene sequence from one amoxicillin-resistant strain with that from HP 26695, the results showed that homology was 90%.Conclusion:.The resistant rates of 84 HP strains acheived from patients to metronidazole, clarithromycin and amoxicillin were separately 67.9% (57/84),17.9%(15/84) and 1.2%(1/84).The result indicated that in Jilin province, HP clinical isolates were most resistant to metronidazole, followed by clarithromycin and amoxicillin less. By amplifing resistant gene fragments from drug-resistant strains, we found that mutations in rdxA geng of metronidazole resistant HP strains were mostly in the form of spot mutation, including the base of the substitution, insertion and deletion mutation without any law.2144 point mutation of Clarithromycin resistant strains in 23 S rRNA happened most frequently.Mutations in 2289,2267,2318 and other sites could also be found.However,no new mutation was found. Homology between one amoxicillin-resistant strain and HP 26695was 90%. Objective:To observe the inhibitory effects of anti-HP lactobacillus acidophilus (LA4 and LA6) on HP strains isolated from clinical patients and induced drug-resistant HP standard strains,and discuss the possibility in using anti-HP lactobacillus acidophilus to assitant with estabilishing antibiotic-resistant HP and preventing from HP re-infection.Methods:Add anti-HP Lactobacillus acidophilus (LA4 and LA6) supernatant to HP strain holes in solid plates,then microaerophilic culture 72 h in 37℃and record inhibition zone. Anti-HP bacterium Lactobacillus acidophilus were also added to HP strains liquid medium. At different time points (4,8,12,24,48 hours after culture), 10μl culture medium was removed from each tube, add to 1ml reaction solution, and tested urease activity. After 24 hours,other 10μl culture medium was diluted to different concentrations and then were inoculated on Brucella medium containing calf serum to observe the growth of HP strains and count colony forming units.Results:In solid culture, anti-HP lactobacillus acidophilus supernatant inhibited all HP strains obviousely.In liquid culture, anti-HP lactobacillus acidophilus can inhibit the proliferation in antibiotic- resistant HP strains and urease activity. All three groups results showed that anti-HP lactobacillus acidophilus(LA4 and LA6) have stronger inhibitory effect on HP than standard lactobacillus acidophilus(LA).Conclusion:Anti-HP acidophilus(LA4 and LA6) significantly inhibited antibiotic- resistant HP strains.
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