Study On The Efficacy Of Different Treatments For Helicobacter Pylori Eradication And Helicobacter Pylori Antibiotic Resistance In Vitro

Objective: Helicobacter pylori (H.pylori) belongs to the microaerophilic gram-negative helicobacter. Since discovered and separated from gastric mucosa by Warren and Marshall in 1983, it was found to be associated with the occurrence of most chronic gastritis, peptic ulcer, gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma. And WHO has classified H.pylori as a classⅠcarcinogenic factor. The infection of H.pylori spreas worldwide, which has a high prevalence of 20%-50% in developed countries. H.pylori infection rate is very high in China, with the lowest rate of 42% in Guangdong province, and the highest rate of 90% in Tibet. So the study of the treatment is very important in the research area of H.pylori infection. Recently triple therapy with a proton pump inhibitor and two antibiotics is recommended as the first-line therapy of H.pylori infection, in which metronidazole, clarithromycin and amoxicillin are commonly used in clinical. However, in recent years substantial researches showed that with the slather using of antibiotics, the rate of antibiotic resistance increased year by year. This is also one of the important reasons for the failure of PPI triple therapy. Because of increasing antibiotic resistance resistance rates and the geographical differences, all regions should focus on a certain number of H.pylori resistant and drug-sensitivity monitoring at a certain period of time, to guide the local selection of the best H.pylori treatment. The purpose of this study is to compare the effects of the four kinds of triple eradication programs (based on PPI add to two kinds of antibiotics), and provide a basis for rational therapy selecting. Aim to know H.pylori resistance to metronidazole, clarithromycin, amoxicillin, furazolidone and levofloxacin resistance from H.pylori in vitro isolation culture and sensitivity test, and to compare the eradication rates with the resistance, and to clear the relevance of Eradication rate with decline in antibiotic resistance.Methods:1 H.pylori Eradication therapy:Between March 2008 and October 2008 a total of 279 aduls were collected sequentially from shijiazhang with no history of antibacterial therapy for eradication. These patients ranged in age from 18 to 70 years with a average age of 44.49±11.46 years, including 148 males, and 126 females, were diagnosed with gastroduodenal diseaserom from Third Hospital of Hebei Medical University. The patients were randomly divided into four groups. Group A (EAM group, n=70) was assigned to receive a 7-day triple therapy consisting of esomeprazole 20 mg (b.i.d.), amoxicillin 1000 mg (b.i.d) and metronidazole 400 mg (b.i.d.). Group B (EAC group, n=70) was assigned to receive a 7-day triple therapy consisting of esomeprazole 20 mg (b.i.d.), amoxicillin 1000 mg (b.i.d) and clarithromycin 500 mg (b.i.d.). Group C(EAF group, n=70 was assigned to receive a 7-day triple therapy consisting of esomeprazole 20 mg (b.i.d.), amoxicillin 1000 mg (b.i.d) and furazolidone 100 mg (b.i.d.). GroupD (EAL group, n=69) was assigned to receive a 7-day triple therapy consisting of esomeprazole 20 mg (b.i.d.), amoxicillin 1000 mg (b.i.d) and levofloxacin 200 mg (b.i.d.). Eradication was assessed by 14C urea breath test 4 weeks after therapy.2 H.pylori isolation , culture and sensitivity test: 131 clinical isolates of H.pylori were isolated from antral biopsy specimens of 279 adults given treatment. H.pylori strains were isolated from antral gastric biopsies. The bacteria were subcultured on Brucella broth agar supplemented with 10% defibrinated sheep blood under the same microaerophilic atmosphere mentioned above (5% O2, 15% CO2, 80% N2) at 37°C for 5~7 days. Of 78 H.pylori successful isolates did sensitivity test. H.pylori isolates were identified by colony morphology, characteristic spiral morphology on Gram staining, and positive findings for catalase, urease and oxidase tests. Fresh strains were prepared from 72 h subculture and spread on plates (90 mm in diameter) containing Brucella broth agar. Drug susceptibility test strips were placed on the plates. The plates were incubated at 37°C under microaerophilic conditions. Inhibition zone diameter values were determined after 72 h incubation, and judge the outcome. SAS 8.0 data statistical software was used for statistical analysis. The differences of rates were analyzed by Chi-square test or Fisher's exact test. A P value of <0.05 was regarded as statistically significant.Results:1 Four were lost to follow-up and sixty-six complete the treatment in group A. One was lost to follow-up and sixty-eight complete the treatment in group D.The effect of different therapies: The eradication rates of the 4 groups were 59.09% (39/66), 77.14% (54/70), 81.43% (57/70) and 85.29% (58/68), respectively. Group A yielded the lowest eradication rates. And the differences were statistically significant with the last three groups (P<0.05). Group D yielded the highest eradication rates. However, the differences were not statistically significant between the last three groups (P>0.05).2 The rates of antibiotic resistance: The metronidazole, amoxicillin, clarithromycin, furaxone and levofloxacin drug resistance of H.pylori were 93.21%, 16.67%, 0%, 2.56% and 5.13% in respective. A total of fifteen trains were multi-drug resistant, the rate was 19.23%(15/78), contining: nine strains resistant to both clarithromycin and metronidazole (11.54%), one strain resistant to both metronidazole and furaxone(1.28%), one strain resistant to both metronidazole and levofloxacin(1.28%), three strains resistant to metronidazole, clarithromycin and levofloxacin(3.85%), and one strain resistant to metronidazole, clarithromycin, furaxone and levofloxacin (1.28%). 3 The relevance of eradication rates and antibiotic resistance: Four patients with metronidazole-sensitive strains were cured. Four patients with metronidazole-resistant strains were not cured and the eradication rate was only 26.67% (4/15). The differences were statistically significant (P<0.05). Fourteen patients with clarithromycin-sensitive strains were cured. Two patients with clarithromycin-resistant strains were not cured. The differences were statistically significant (P<0.05). Twenty three patients with furaxone-sensitive strains were cured. One patient with furaxone-resistant strain was not cured. The differences were statistically significant (P<0.05). Eighteen patients with levofloxacin-sensitive strains were cured. One patient with levofloxacin-resistant strain was not cured.Conclusions:1 From the four H.pylori eradication therapies commonly used in clinical, the one united levofloxacin yielded the highest rate, and the one united metronidazole yielded the lowest rate.2 The main reason of the triple treatment failure is Antibiotic resistance. The metronidazole drug resistance rate of H.pylori was the highest in Shijiazhuang, reaching 92.31%. The eradication rate of PPI triple treatment united metronidazole was only 59.09%.This program does not fit in the region of H.pylori eradication therapy. The amoxicillin, furazolidone, levofloxacin drug resistance of H.pylori were low. The eradication rates were relatively high, but still can not achieve the desired goal of the eradication effect (>90%). Therefore, triple therapy with seven days is not ideal. It's required to assess the effect of extending the course of treatment, quadruple therapy or sequential therapy in the region.