Inhibitory effects of emodin,baicalin, schizandrin and berberine on hef A gene: Treatment of Helicobacter pylori-induced multidrug resistance

AIM: To investigate the inhibitory effects of emodin, baicalin, etc. on the hefA gene of multidrug resistance(MDR) in Helicobacter pylori(H. pylori).METHODS: The double dilution method was used to screen MDR H. pylori strains and determine the minimum inhibitory concentrations(MICs) of emodin, baicalin, schizandrin, berberine, clarithromycin, metronidazole, tetracycline, amoxicillin and levofloxacin against H. pylori strains. After the screened MDR stains were treated with emodin, baicalin, schizandrin or berberine at a 1/2 MIC concentration for 48 h, changes in MICs of amoxicillin, tetracycline, levofloxacin, metronidazole and clarithromycin were determined.MDR strains with reduced MICs of amoxicillin were selected to detect the hefA mR NA expression by realtime quantitative PCR.RESULTS: A total of four MDR H. pylori strains were screened. Treatment with emodin, baicalin, schizandrin and berberine significantly decreased the MICs of amoxicillin and tetracycline against some strains, decreased by 1 to 2 times, but did not significantly change the MICs of clarithromycin, levofloxacin, and metronidazole against MDR strains. In the majority of strains with reduced MICs of amoxicillin, hef A m RNA expression was decreased; one-way ANOVA(SPSS 12.0) used for comparative analysis, P < 0.05.CONCLUSION: Emodin, baicalin, schizandrin and berberine significantly decreased the MICs of amoxicillin and tetracycline against some H. pylori strains, possibly by mechanisms associated with decreasing hefA mR NA expression.     

维生素C注射液和头孢曲松钠用于复发性口腔溃疡的效果比较

[目的]观察维生素C和头孢曲松钠用于复发性口腔溃疡护理的效果。[方法]将2012年1月—2014年1月本科收治的复发性口腔溃疡病人90例,按方便抽样的方法随机分为两组。对照组给予维生素B2口服;观察组将1支国产头孢曲松钠和1支维生素C注射液调匀成糊状,置于玻璃容器内,用棉签蘸取少许涂于溃疡表面,每天3次,共治疗6d。比较两组治疗后效果、进食改善至正常的时间、口腔溃疡愈合时间。[结果]两组治疗后的效果、进食改善至正常的时间、口腔溃疡愈合时间比较差异有统计学意义(P<0.05)。[结论]采用维生素C和头孢曲松钠用于口腔溃疡效果好,无明显不良反应。     

The efficacy of levofloxacin based triple therapy for Helicobacter pylori eradication]

BACKGROUND/AIMS: The failure rates of first and second line therapies of Helicobacter pylori (H. pylori) eradication range from 15 to 20%. This study was aimed to evaluate the efficacy and safety of levofloxacin based triple therapy compared with standard triple or quadruple therapy for H. pylori eradication in Korea. METHODS: We enrolled two hundred and sixty seven patients with presence of H. pylori infection. One hundred and forty-one patients were treated with levofloxacin based triple therapy (LAP; levofloxacin, amoxicillin, proton pump inhibitor; PPI), and 126 patients were treated with standard triple therapy (CAP; clarithromycin, amoxicillin, PPI). We retreated the patients who had failed in H. pylori eradication with standard quadruple second-line therapy (MTPB; metronidazole, tetracycline, PPI, bismuth subcitrate) or levofloxacin based therapy (LAP or LCP; levofloxacin, clarithromycin, PPI). RESULTS: In first line therapy of H. pylori eradication, the eradication rates of levofloxacin based triple therapy and standard triple therapy were 69.8% and 74.0% respectively (p=0.52). In second-line therapy, the eradication rate of levofloxacin based triple therapy and standard quadruple therapy were 62.5% and 40.0% respectively (p=0.34). CONCLUSIONS: Levofloxacin based triple therapy is effective as standard regimen to eradicate H. pylori infection and is useful for an alternative rescue therapy as well.     

Resistance to metronidazole, clarithromycin and levofloxacin of Helicobacter pylori before and after clarithromycin-based therapy in Taiwan

Background and Aim:  Clarithromycin-based triple therapy has been commonly applied as the first-line therapy for Helicobacter pylori eradication. Levofloxacin could serve as an alternative in either first-line or second-line regimens. This study surveyed the prevalence of levofloxacin resistance of H. pylori isolates in naive patients and in patients with a failed clarithromycin-based triple therapy.
Methods:  The study collected the H. pylori isolates from 180 naive patients and 47 patients with a failed clarithromycin-based triple therapy. Their in vitro antimicrobial resistance was determined by E -test.
Results:  The naive H. pylori isolates had resistance rates for amoxicillin, levofloxacin, clarithromycin and metronidazole of 0%, 9.4%, 10.6% and 26.7%, respectively. An evolutional increase of the primary levofloxacin resistance was observed in isolates collected after 2004, as compared to isolates collected before 2004 (16.3% vs 3.2%, P  = 0.003). There was no evolutional increment of the primary clarithromycin resistance. The clarithromycin resistance elevated significantly after a failed clarithromycin-based triple therapy (78.7% vs 10.6%, P  < 0.001). The post-treatment isolates remained to have a levofloxacin resistance rate of near 17%, but the levofloxacin-resistant isolates were correlated with a higher incidence of metronidazole resistance ( P  = 0.023). No strain was found to be resistant to amoxicillin even after eradication failure.
Conclusion:  The levofloxacin resistance of naive H. pylori remains less than 10% in Taiwan. With relatively lower resistance to levofloxacin than to metronidazole of the H. pylori isolates collected after a failed clarithromycin-based therapy, proton pump inhibitor–levofloxacin–amoxicillin may be an alternative choice to serve as the second-line therapy.     

High-dose versus low-dose clarithromycin in 1-week triple therapy, including rabeprazole and levofloxacin, for Helicobacter pylori eradication

GOALS: To compare high-dose versus low-dose clarithromycin in 1-week triple therapy including rabeprazole and levofloxacin. BACKGROUND: Regimens containing rabeprazole and levofloxacin have proved to be effective against H. pylori infection. STUDY: One-hundred H. pylori-positive patients were randomly assigned to one of the following 1-week regimens: rabeprazole 20 mg o.d. plus levofloxacin 500 mg o.d. and clarithromycin 250 mg b.d. (RLC-1 group); rabeprazole 20 mg o.d. plus levofloxacin 500 mg o.d. and clarithromycin 500 mg b.d. (RLC-2 group). H. pylori status was assessed at entry and after the treatment. Patients who experienced treatment failure underwent antibiotic susceptibility testing. RESULTS: Forty-two patients in RLC-1 group (both PP and ITT analysis: 84%; 95%CI: 71-93%) and 47 in RLC2 group (both PP and ITT analysis: 94%; 95% CI: 83-98%) became H. pylori negative. Clarithromycin resistance was detected in all of 8 (100%) RLC-1 failures and in 1 out of 3 (33%) RLC-2 failures. Side effects occurred in 8% of patients in RLC-1 group and in 12% in RLC-2. CONCLUSIONS: Regimens tested are competitive with other PPI-based treatments. One-week triple therapy containing rabeprazole plus, levofloxacin, and high-dose clarithromycin yielded a higher eradicating rate than the one containing low-dose clarithromycin and may be considered as a first-line therapy option.     

Pharmacological therapy used in the elimination of Helicobacter pylori infection:A review

The optimal therapy for Helicobacter pylori(H.pylori) infection should combine a high cure rate and a short treatment duration with a favorable side-effect profile and should maintain a low cost.Several strategies have been proposed to increase the H.pylori eradication rate,including the extension of the treatment duration to 14 d,the use of a four-drug regimen(quadruple,sequential,and concomitant treatments),and the use of novel antibiotics,such as levofloxacin.However,triple therapy remains the most widely accepted firstline treatment regimen in Brazil and the United Statesand throughout Europe.Because this therapy is limited by resistance to clarithromycin,other therapeutic regimens have been investigated worldwide.This review describes the current literature involving studies directly comparing these different therapies and their efficacies.     

Five-year sequential changes in secondary antibiotic resistance of Helicobacter pylori in Taiwan

AIM: To determine changes in the antibiotic resistance of Helicobacter pylori(H. pylori) in southern Taiwan after failure of first-line standard triple therapy.METHODS: We analyzed 137 H. pylori-infected isolates from patients who experienced eradication failure after standard first-line triple therapy from January2010 to December 2014. The H. pylori strains were tested for susceptibility to amoxicillin, clarithromycin,levofloxacin, metronidazole and tetracycline using the E-test method. The minimal inhibitory concentration(MIC) was determined by the agar dilution test.MIC values of ≥ 0.5, ≥ 1, ≥ 1, ≥ 4 and ≥ 8 mg/L were considered to be the resistance breakpoints for amoxicillin, clarithromycin, levofloxacin, tetracycline and metronidazole, respectively.RESULTS: A high resistance rate was found for clarithromycin(65%-75%) and metronidazole(30%-40%)among patients who failed first-line standard therapy.The resistance levels to amoxicillin and tetracycline remained very low; however, levofloxacin resistance was as high as 37.5% in 2010 but did not increase any further during the past 5 years. The rates of resistance to these antibiotics did not show a statistically significant upward or downward trend.CONCLUSION: Antibiotic resistance of H. pylori remains a problem for the effective eradication of this pathogen and its associated diseases in Taiwan. High clarithromycin resistance indicated that this antibiotic should not be prescribed as a second-line H. pylori eradication therapy. Moreover, levofloxacin-based second-line therapy should be used cautiously, and the local resistance rates should be carefully monitored.     

Prevalence of Helicobacter pylori resistance to clarithromycin and metronidazole determined by 23S ribosomal RNA and rdxA gene analyses in Hiroshima,Japan

BACKGROUND AND AIMS: Resistance to antibiotics in Helicobacter pylori is increasing and becoming a serious problem in eradication treatment of H. pylori. The prevalence of H. pylori infections that are resistant to clarithromycin, metronidazole, or both were determined in H. pylori isolates in Hiroshima, Japan. METHODS: Sixty Japanese patients with H. pylori infection were collected between 1999 and 2000. To detect the resistance to clarithromycin and metronidazole, mutations of the 23S ribosomal RNA (rRNA) and rdxA genes that are responsible for resistance in H. pylori, were examined by direct sequencing analysis. RESULTS: Resistance to clarithromycin and metronidazole was detected in 12 (20.0%) and nine (15.0%) of the patients, respectively. Dual resistance to clarithromycin and metronidazole was detected in five (8.3%) patients. CONCLUSION: These results indicate that the relatively high prevalence of the dual resistance in H. pylori isolates may need special attention and new therapeutic approaches in Japan.     

幽门螺杆菌对克拉霉素耐药的分子机制研究

目的：研究幽门螺杆菌（Hp)对克拉霉素耐的分子机制。方法：用E－test进行克拉霉素药敏试验,选取治疗前敏感、治疗后耐药的配对菌株及原发耐药Hp菌株进行研究;应用随机扩增多态性DNA（RAPD）分析,确定治疗前后菌株的同一性;用PCR－限制性片段长度多态性（RFLP）分析探讨克拉霉素耐药机制。结果9株克拉霉素耐药菌23SrRNA基因功能区V PCR扩增片段,8株被BsaI酶切,9株均未被BbsI酶切,提示8株在2144位点有A→G突变。结论上海地区大多数克拉霉素耐药Hp菌株存在23SrRNA基因功能区V2144位点A→G突变。     

One-week once-daily triple therapy with esomeprazole, levofloxacin and azithromycin compared to a standard therapy for Helicobacter pylori eradication

BACKGROUND: Primary antibiotic-resistance and poor compliance are the main causes of Helicobacter pylori eradication failure of standard regimens. AIM: To investigate eradication rate, patient compliance and tolerability of a 1-week once-daily levofloxacin plus azithromycin triple therapy versus the standard twice-daily triple therapy. PATIENTS AND METHODS: A total of 164 H. pylori-positive patients were randomised to either esomeprazole 20mg, levofloxacin 500 mg and azithromycin 500 mg once-daily (ELAz) or esomeprazole 20mg, clarithromycin 500 mg and amoxycillin 1g twice-daily (ECA) for 1 week. H. pylori infection was defined at entry by histology and urea breath test; cure of infection was determined both by negative urea breath test and H. pylori stool antigens. RESULTS: H. pylori eradication rates of ELAz and ECA were similar at intention-to-treat (both 65%) and per-protocol analyses (70% versus 76%, respectively). Incidence of poor compliance was lower, although not significantly, in patients randomised to ELAz than to ECA (4% versus 10%); tolerability was significantly higher for ELAz than for ECA (88% versus 70%; P=0.01). CONCLUSIONS: Once-daily levofloxacin plus azithromycin-based triple therapy achieves an H. pylori eradication rate comparable to that of standard twice-daily triple therapy, but is associated with higher patient compliance and might even be better tolerated.     

Institutional difference of antibiotic resistance of Helicobacter pylori strains in Korea

GOALS: This study was performed to evaluate whether the prevalence rates of primary antibiotic resistance in Helicobacter pylori isolates could be different between 2 institutions, which are located in the different areas in Korea, and to evaluate the effect of antibiotic resistance on the eradication rate of H. pylori. STUDY: H. pylori were isolated from gastric mucosal biopsy specimens obtained from 113 Koreans, who did not have any eradication history. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin, and moxifloxacin were examined according to the agar dilution method by 1 technician. RESULTS: All of these patients were treated with the same regimen, proton pump inhibitor-amoxicillin-clarithromycin triple therapy. There was a statistical difference in resistance to metronidazole, levofloxacin, and moxifloxacin among 6 antibiotics between 2 institutions located in Seoul and Gyeonggi province. The rates of eradication were 94.2% for the clarithromycin and amoxicillin-susceptible strains, and 42.8% for the amoxicillin-susceptible and clarithromycin-resistant strains. In contrast, eradication rate was 100% for the amoxicillin-resistant strains. CONCLUSIONS: These results show that there is institutional difference of antibiotic resistance of H. pylori, explaining the institutional difference of eradication rate of H. pylori. The resistance to clarithromycin seems to be an important determinant for the eradication by proton pump inhibitor triple therapy but resistance to amoxicillin does not have any effect.     

Patterns of Helicobacter pylori isolate resistance to fluoroquinolones, amoxicillin, clarithromycin and metronidazoles

Helicobacter pylori eradication using the three antibiotic regimen of amoxicillin, clarithromycin and metronidazole often fails, making it imperative to find substitutes. The following study made use of 72 H. pylori isolates derived from pyloric antrum mucosa biopsies of gastritis and chronic dyspepsia patients treated at the Cipto Mangunkusumo National General Hospital and three private hospitals in Jakarta. Testing for H. pylori sensitivity to various antimicrobials was conducted using the disk diffusion method (Kirby Bauer) and procedures determined by the Clinical and Laboratory Standards Intitute (CLSI)/NCCLS. The resistance rates of the isolates were 100% for metronodazole, 27.8% for clarithromycin, 19.4% for amoxicillin, 6.9% for ciprofloxacin, norfloxacin and ofloxacin, 2.8% for sparfloxacin and gatifloxacin, and 1.4% for levofloxacin and moxifloxacin. Fluoroquinolons have the lowest resistance compared to amoxicillin, clarithromycin and metronidazole.     

Antimicrobial susceptibility of Canadian isolates of Helicobacter pylori in Northeastern Ontario

BACKGROUND:

Helicobacter pylori plays a significant role in gastritis and ulcers. It is a carcinogen as defined by the WHO, and infection can result in adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. In Canada, rates of antimicrobial resistance are relatively unknown, with very few studies conducted in the past 15 years.

OBJECTIVE:

To examine rates of resistance in Sudbury, Ontario, compare antimicrobial susceptibility methods and attempt to determine the molecular basis of antibiotic resistance.

METHODS:

Patients attending scheduled visits at Health Sciences North (Sudbury, Ontario) provided gastric biopsy samples on a volunteer basis. In total, 20 H pylori isolates were collected, and antimicrobial susceptibility testing (on amoxicillin, tetracycline, metronidazole, ciprofloxacin, levofloxacin and clarithromycin) was conducted using disk diffusion and E-test methods. Subsequently, genomic DNA from these isolates was sequenced to detect mutations associated with antimicrobial resistance.

RESULTS:

Sixty-five percent of the isolates were found to be resistant to at least one of the listed antibiotics according to E-test. Three isolates were found to be resistant to ≥3 of the above-mentioned antibiotics. Notably, 25% of the isolates were found to be resistant to both metronidazole and clarithromycin, two antibiotics that are normally prescribed as part of first-line regimens in the treatment of H pylori infections in Canada and most of the world. Among the resistant strains, the sequences of 23S ribosomal RNA and gyrA, which are linked to clarithromycin and ciprofloxacin/levofloxacin resistance, respectively, revealed the presence of known point mutations associated with antimicrobial resistance.

CONCLUSIONS:

In general, resistance to metronidazole, ciprofloxacin/levofloxacin and clarithromycin has increased since the studies in the early 2000s. These results suggest that surveillance programs of H pylori antibiotic resistance may need to be revisited or improved to prevent antimicrobial therapy failure.     

Levofloxacin-based triple therapy in first-line treatment for Helicobacter pylori eradication

BACKGROUND:  The standard first-line therapies for Helicobacter pylori eradication are based on clarithromycin and amoxicillin or metronidazole. Recent studies suggested levofloxacin as an alternative option for both first-and second-line H. pylori eradication treatment.
AIMS:  To compare efficacy and tolerability of two different 7-day standard triple therapies versus 7-day levofloxacin-based triple therapy in first-line treatment for H. pylori infection.
METHODS:  Three hundred consecutive H. pylori positive patients were randomized to receive: clarithromycin, amoxicillin, esomeprazole (Group A: N = 100); clarithromycin, metronidazole, esomeprazole (Group B: N = 100); or clarithromycin, levofloxacin, esomeprazole (Group C: N = 100). H. pylori status was rechecked by ¹³C urea breath test 6 wk after the end of therapy.
RESULTS:  Sixteen out of 300 patients discontinued treatment because of the occurrence of side effects (Group A, 5; Group B, 7; Group C, 4). The eradication rates in intention to treat (ITT) and per protocol (PP) analyses were: Group A, 75% and 79%; Group B, 72% and 77.4%; and Group C, 87% and 90.6%. The eradication rate achieved with levofloxacin-based triple therapy was significantly higher than that with standard therapies in either ITT (87% vs 75%, p <0.05; 87% vs 72%, p <0.01;) or PP analysis (90.6% vs 79%, p <0.05; 90.6 vs 77.4, p <0.05). No difference was found between standard triple therapies. The incidence of side effects was similar among groups.
CONCLUSIONS:  A 7-day levofloxacin-based triple therapy can achieve higher H. pylori eradication rates than standard regimens. These data suggest levofloxacin-based regimens can be the most effective in first-line anti- H. pylori therapy, at least in the Italian population.     

Concomitant therapy achieved the best eradication rate for Helicobacter pylori among various treatment strategies

AIM: To compare the Helicobacter pylori(H.pylori) eradication rate of clarithromycin-based triple therapy,metronidazole-based triple therapy,sequential therapy and concomitant therapy.METHODS: A total of 680 patients infected with H.pylori were divided into 4 groups and each group was treated with a different eradication therapy.Clarithromycin-based triple therapy was applied to the first group [rabeprazole,amoxicillin and clarithromycin(PAC) group: proton pump inhibitor(PPI),amoxicillin,clarithromycin],whereas the second group was treated with metronidazole-based triple therapy [rabeprazole,amoxicillin and metronidazole(PAM) group: PPI,amoxicillin,metronidazole].The third group was treated with rabeprazole and amoxicillin,followed by rabeprazole,clarithromycin and metronidazole(sequential group).The final group was simultaneously treated with rabeprazole,amoxicillin clarithromycin and metronidazole(concomitant therapy group).In the case of a failure to eradicate H.pylori,second-line quadruple and third-line eradication therapies were administered.RESULTS: The per protocol(PP) analysis was performed on 143,139,141 and 143 patients in the PAC,PAM,sequential and concomitant groups,respectively.We excluded patients who did not receive a C13-urea breath test(22,20,23 and 22 patients,respectively) and patients with less than an 80% compliance level(5,11,6 and 5 patients,respectively).The eradication rates were 76.2%(109/143) in the PAC group,84.2%(117/139) in the PAM group,84.4%(119/141) in the sequential group and 94.4%(135/143) in the concomitant group(P = 0.0002).All 14 patients who failed second-line therapy were treated with thirdline eradication therapy.Among these 14 patients,6 infections were successfully eradicated with the thirdline therapy.Both PP and intention-to-treat analysis showed an eradication rate of 42.9%(6/14).In the PAC group,3 of 4 patients were successfully cured(3/4,75%); 2 of 2 patients in the PAM group(2/2,100%) and 1 of 5 patients in the sequential group(1/5,20%) were also cured.In the concomitant group,all 3 patients failed(0/3,0%).CONCLUSION: The eradication rate for the concomitant therapy was much higher than those of the standard triple therapy or sequential therapy(Clinical Trials.gov number NCT01922765).     

New mutation points in 23S rRNA gene associated with Helicobacter pylori resistance to clarithromycin in northeast China

AIM: To investigate the resistance rate of Helicobacter pylori (H pylori ) to clarithromycin, metronidazole, amoxicillin and tetracycline to guide clinical practice, and to study the mechanism of H pylori resistant to clarithromycin. METHODS: Thirty H pylori strains were isolated from the mucosa of peptic ulcer, gastric tumor and chronic gastritis patients, then the minimal inhibitory concentration (MIC) to clarithromycin, metronidazole, amoxicillin and tetracycline was evaluated by E-test method. The sequence analysis of PCR fragments was conducted in 23S rRNA gene of H pylori resistant to clarithromycin to get the resistance mechanism of the bacteria. RESULTS: Among 30 H pylori strains, 7 cases were resistant to clarithromycin, 12 to metronidazole, 2 to tetracycline and no strain was found to be resistant to amoxicillin. The resistance rates were 23.3%, 40%, 6.7% and 0%, respectively. Three new mutation points were found to be related to the clarithromycin resistance in H pylori isolates, which were G2224A, C2245T and T2289C. CONCLUSION: In northeast China, H pylori shows high resistance to metronidazole, while sensitive to amoxicillin. The mechanism of resistance to clarithromycin may be related to the mutation of G2224A, C2245T and T2289C in the 23S rRNA gene.     

Antibiotic resistance of Helicobacter pylori isolated from Korean patients]

The distribution of minimal inhibitory concentrations (MIC) for amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, and fluoroquinolone (ciprofloxacin, levofloxacin, and moxifloxacin) have shifted to higher concentrations from 1987 to 2003 in Helicobacter pylori (H. pylori) strains isolated from Korean patients. MIC values of secondary isolates were higher than those of primary isolates. Of treatment-failure patients, 16.4% showed mixed infections with both antibiotic-susceptible and -resistant H. pylori strains. A total of 89.6% of patients with treatment failure and 52.3% of patients without antibiotic treatment had H. pylori strains resistant to two or more antimicrobial agents (multi-drug resistance, MDR). The most common antibiotics showing MDR were clarithromycin, metronidazole, and azithromycin. The resistance rates to both amoxicillin and clarithromycin were 34.3% in secondary isolates and 6.2% in primary isolates. The resistance rates to both clarithromycin and metronidazole were 73.1% in secondary isolates and 7.7% in primary isolates. In addition, there was a significant difference in antibiotic resistance between two institutions located at Seoul and Gyeonggi provinces. To provide adequate informations about susceptible antibiotics to clinicians, continuous surveillance of antibiotic susceptibilities is needed in Korea.     

山西省243株幽门螺杆菌药物敏感性及克拉霉素耐药基因突变特征分析

目的 了解山西幽门螺杆菌（Helicobacter pylori,H.pylori）对5种抗生素药物敏感性及其克拉霉素耐药相关基因突变特征.方法 收集临床分离的H.pylori243株,采用纸片扩散法检测H.pylori对5种抗菌药物的敏感性.选取所有耐克拉霉素及相当数量的敏感菌株,提取基因组DNA,PCR法扩增23SrRNA基因功能区并测序,测序结果采用DNAStar软件包分析.统计结果分析采用x2检验和Fisher精确概率法.结果 临床分离的243株H.pylori,药敏结果显示对甲硝唑,克拉霉素,阿莫西林,左氧氟沙星和呋喃唑酮5种药物的耐药率分别为：75.3％（183/243）,7.4％（18/243）,7.4％（18/243）,12.4％（30/243）,8.6％（21/243）,5种药物的耐药率有统计学意义（P＜0.05）.结论 H.pylori临床菌株对甲硝唑,左氧氟沙星,克拉霉素、阿莫西林及呋喃唑酮存在不同程度的耐药,以对甲硝唑耐药率最高.克拉霉素耐药菌株23SrRNA基因突变以A2143C为主,此突变可能与该地区H.pylori耐药性有关,此外,还发现了A2214G位点的突变.     

Seven-day triple therapy is a better choice for Helicobacter pylori eradication in regions with low antibiotic resistance

AIM: To investigate whether 7-d triple therapies are still valid in populations with low levels of resistance.METHODS: A total of 1106 Helicobacter pylori(H. pylori)-positive patients were divided into three groups,each of which received one type of 7-d triple therapy. Therapeutic outcomes of the patients were assessed by the 13C-urea breath test at 8 wk after treatment. The susceptibility of H. pylori to antibiotics was determined by an agar-dilution method. Data analysis was performed by χ2 tests.RESULTS: The eradication rates in groups A,B and C were 90.71%(332/366),90.46%(313/346) and 90.87%(189/208),respectively(P = 0.986). The resistance rates were 8.91% for clarithromycin,14.78% for levofloxacin and 0% for amoxicillin. The eradication rate was significantly different between clarithromycin-and levofloxacin-resistant patients(P 0.05) in group A. Patients whose treatment failed in group A also had a higher clarithromycin resistance rate than did successive patients(P = 0.034). However,levofloxacin resistance had no obvious influence on the eradication rate. Furthermore,three main antibiotics(clarithromycin,levofloxacin and amoxicillin) had lower DID(defined daily dose per 1000 inhabitants per day) in this city.CONCLUSION: Clarithromycin resistance is the main reason for the failure of 7-d triple therapy. In populations with low levels of resistance,a 7-d triple therapy is a viable choice. The choice of therapy should not be influenced by conditions in high antibiotic resistance regions.     

High Helicobacter pylori resistance rate to clarithromycin in Turkey

GOALS: To assess the resistance of Helicobacter pylori to clarithromycin in Turkey. BACKGROUND: Recent studies have emphasized the remarkable reduction in H. pylori eradication rates. Resistance to clarithromycin is the most important factor affecting the success of H. pylori eradication therapies. STUDY: The study involved 110 consecutive adult dyspeptic patients infected with H. pylori. Resistance to clarithromycin was studied by real-time polymerase chain reaction method on gastric biopsy specimens. RESULTS: Of the 110 patients, 56 (50.9%) were male and mean age (+/-SD) was 45.1+/-13.1 years. Overall, 53 (48.2%) patients were found to be resistant to clarithromycin. Resistance to clarithromycin was not statistically associated with age, sex, previous macrolide use, residence (urban/rural), education status, and presence of peptic ulcer. CONCLUSIONS: The rate of resistance to clarithromycin was found to be markedly high. This result may explain the recently reported low success rates of H. pylori eradication therapies with clarithromycin.