Third Chinese National Consensus Report on the management of Helicobacter pylori infection

The Efficacy and Safety of Regimens for Helicobacter pylori Eradication Treatment in China: A Systemic Review and Network Meta-Analysis

BACKGROUND

With Helicobacter pylori's increasing antibiotic resistance, evidence of more effective treatments is lacking in China, where H. pylori prevalence is nearly 50%. Thus, we performed a network meta-analysis to compare therapeutic regimens.

METHODS

Data extracted from eligible randomized controlled trials from January 2000 to September 2021 were entered into a Bayesian hierarchical random-effects model to evaluate the efficacy and safety of H. pylori eradication regimens.

RESULTS

This study included 101 trials involving 21,745 patients. Vonoprazan-bismuth-containing quadruple therapy (VBQT) ranked the highest [surfaces under cumulative ranking curve (SUCRA), 83.64%], followed by high-dose amoxicillin dual therapy (HDDT) [SUCRA, 79.70%, odds ratio (OR)=1.31, 95% credible interval (CrI) (0.36, 4.72)] and proton pump inhibitor-based bismuth-containing quadruple therapy (BQT) [SUCRA, 63.59%, OR=1.59, 95% CrI (0.48, 5.24)]. HDDT [OR=2.47, 95% CrI (1.51, 4.06)], BQT [OR=2.04, 95% CrI (1.69, 2.47)], concomitant quadruple nonbismuth therapy (CT) [OR=1.93, 95% CrI (1.19, 3.15)], and sequential therapy (ST) [OR=1.86, 95% CrI (1.50, 2.32)] had higher eradication rates than standard triple therapy (TT). ST (SUCRA, 82.52%) and VBQT (SUCRA, 83.89%) had the highest eradication rate before and after 2010 in the effectiveness ranking, respectively. Furthermore, the H. pylori eradication rate of patients receiving 14-day BQT treatment was higher than that of 10-day BQT regimen [OR=2.55, 95% CI (1.84, 3.53)] and 7-day BQT regimen [OR=3.64, 95% CI (2.64, 5.01)].

CONCLUSIONS

The TT regimen was not an optimal choice in China for H. pylori eradication; VBQT, HDDT, and BQT showed better efficacy. After 2010, there is a trend toward significance that VBQT provided a higher H. pylori eradication rate in China, but with only 1 randomized controlled trial. Thus, more supportive real-world data are needed to confirm its effectiveness.

Is tailored therapy based on antibiotic susceptibility effective ? a multicenter, open-label, randomized trial

An effective eradication therapy of Helicobacter pylori (H. pylori) should be used for the first time. In this study, we assessed whether tailored therapy based on antibiotic susceptibility testing is more effective than traditional therapy. We also evaluated the factors that cause treatment failure in high-resistance areas. For this multicenter trial, we recruited 467 H. pylori-positive patients. The patients were randomly assigned to receive tailored triple therapy (TATT), tailored bismuth-containing quadruple therapy (TABQT), or traditional bismuth-containing quadruple therapy (TRBQT). For the TATT and TABQT groups, antibiotic selection proceeded via susceptibility testing using an agar-dilution test. The patients in the TRBQT group were given amoxicillin, clarithromycin, esomeprazole, and bismuth. Successful eradication was defined as a negative ¹³C-urea breath test at least eight weeks after the treatment ended. Susceptibility testing was conducted using an agar-dilution test. The eradication rate was examined via intention-to-treat (ITT) and per-protocol (PP) analyses. The clarithromycin, levofloxacin, and metronidazole resistance rates were 26.12%, 28.69%, and 96.79%, respectively. Resistance against amoxicillin and furazolidone was rare. The eradication rates for TATT, TRBQT, and TABQT were 67.32%, 63.69%, and 85.99% in the ITT analysis (P 0.001) and 74.64%, 68.49%, and 91.22% in the PP analysis (P 0.001), respectively. The efficacy of TABQT was affected by clarithromycin resistance, and bismuth exerted a direct influence on TATT failure. TABQT was the most efficacious regimen for use in high-resistance regions, especially among clarithromycin-susceptible patients.

Chinese Classical Formula Sijunzi Decoction and Chronic Atrophic Gastritis: Evidence for Treatment Approach?

Objective

This aim is to evaluate the effect of Sijunzi decoction (SJZD) treating chronic atrophic gastritis (CAG).

Methods

We performed searches in seven databases. The randomized controlled trials (RCTs) comparing SJZD with standard medical care or inactive intervention for CAG were enrolled. Combined therapy of SJZD plus conventional therapies compared with conventional therapies alone was also retrieved. The primary outcome included the incidence of gastric cancer and the improvement of atrophy, intestinal metaplasia, and dysplasia based on the gastroscopy and pathology. The secondary outcomes were Helicobacter pylori clearance rate, quality of life, and adverse event/adverse drug reaction.

Results

Six RCTs met the inclusion criteria. The research quality was low in the trials. For the overall effect rate, pooled analysis from 4 trials showed that modified SJZD plus conventional medications exhibited a significant improvement (OR = 4.86; 95% CI: 2.80 to 8.44; P < 0.00001) and without significant heterogeneity compared with the conventional medications alone. None reported the adverse effect.

Conclusions

Modified SJZD combined with conventional western medicines appears to have benefits for CAG. Due to the limited number and methodological flaw, the beneficial and harmful effects of SJZD for CAG could not be identified. More high-quality clinical trials are needed to confirm the results.

Effectiveness of Helicobacter pylori eradication in the prevention of primary gastric cancer in healthy asymptomatic people: A systematic review and meta-analysis comparing risk ratio with risk difference

BACKGROUND

Helicobacter pylori infection is strongly associated with gastric cancer occurrence. However, it is unclear whether eradication therapy reduces the risk of gastric cancer occurrence. We evaluated whether H. pylori eradication reduces the risk of primary gastric cancer by using both risk ratio (RR) and risk difference (RD).

METHODS

Searches of PubMed, EMBASE, Google scholar, the Cochrane Library, and the Japan Medical Abstracts Society as well as those registered in databases of the Cochrane Central Register of Controlled Trials, metaRegister of Controlled Trials, ClinicalTrials.gov, controlled-trials.com, UMIN-CTR, JMACCT-CTR, and JAPIC-CTI between January 1965 and March 2017, supplemented with manual screening. Randomized controlled trials (RCTs) in which eradication therapy were implemented for the interventional group but not for the control group, and assessed the subsequent occurrence of primary gastric cancer as the main outcome. Two authors independently reviewed articles and extracted data. Integrated results for all data were presented as RR and RD.

RESULTS

Seven studies met inclusion criteria. The reductions in risk of primary gastric cancer occurrence in terms of overall RR and RD were 0.67 (95% CI: 0.48 to 0.95) and -0.00 ([95% CI: -0.01 to 0.00]; number needed to treat: 125.5 [95% CI: 70.0 to 800.9]), respectively.

CONCLUSIONS

The effectiveness of H. pylori eradication therapy in suppressing the occurrence of primary gastric cancer was significant and comparable to that of previous studies in terms of the estimated RR. However, the estimated RD was slight and not statistically significant.

Randomized clinical trial comparing 10-day sequential, 7-day concomitant and 7-day standard triple therapies for Helicobacter pylori eradication

OBJECTIVES

To compare triple therapy with sequential and concomitant therapies directly in a head-to-head comparison in Helicobacter pylori-infected patients.

DESIGN

Patients were allocated randomly as follows: a triple therapy with esomeprazole (20 mg), amoxicillin (1000 mg) and clarithromycin (500 mg) twice daily for 7 days; a sequential therapy with 5 days of esomeprazole (20 mg) and amoxicillin (1000 mg) twice daily, followed by 5 days of esomeprazole (20 mg), clarithromycin (500 mg) and metronidazole (400 mg) twice daily; or a concomitant therapy consisting of esomeprazole (20 mg), amoxicillin (1000 mg), clarithromycin (500 mg) and metronidazole (400 mg) twice daily for 7 days.

RESULTS

A total of 356 consecutive patients were included. The eradication rates for the triple, sequential and concomitant therapies were 83.6% [95% confidence interval (CI) 76.9-90.4%], 94.2% (95% CI 90.0-98.4%) and 91.7% (95% CI 86.7-96.6%), respectively, in the intention-to-treat population. The differences were significant only between triple and sequential therapies (P=0.01). The primary resistance rates to amoxicillin, clarithromycin and metronidazole were 0.6, 10.5 and 25.9%, respectively. Concomitant therapy was significantly better than triple therapy in cases with clarithromycin resistance (P=0.01).

CONCLUSION

Ten-day sequential therapy was significantly better than 7-day triple therapy in a clinical setting with low rates of clarithromycin and dual resistance. Concomitant therapy was significantly better than standard triple therapy in the subgroup of patients with clarithromycin-resistant strains.

Effects of daily telephone-based re-education before taking medicine on Helicobacter pylori eradication: A prospective single-center study from China

AIM: To investigate the effects of daily telephone-based re-education (TRE) before taking medicine for the eradication of Helicobacter pylori (H. pylori) on the compliance and the eradication rate in a Chinese patient population.

METHODS: A prospective, physician-blinded, randomized, controlled clinical study was conducted. The patients were randomly assigned to receive TRE every day before taking medicine (TRE group) or no TRE (control group). The patients in the TRE group received regular instructions before taking medicine for the eradication of H. pylori during the entire course of treatment through telephone calls. The patients in the control group received detailed instructions at the time of seeing a doctor for the guidance. The primary outcome was the H. pylori eradication rate after treatment. The secondary outcomes included the clinical remissions after treatment, adverse events, compliance, and patients’ satisfaction.

RESULTS: A total of 140 patients were randomized, 70 to the TRE group and 70 to the control group. As the primary outcome, the H. pylori eradication rates in the TRE and control groups were 62.7% and 71.2% in per protocol analysis (P = 0.230), and 52.9% and 52.9% in intention-to-treat analysis (P = 0.567), respectively. As the secondary outcomes, there were no significant differences in the patients’ satisfaction between the two groups (good, 79.7% vs 76.9%; fair, 13.6% vs 19.2%; poor, 6.7% vs 3.9%, for the TRE group and control group, respectively; P > 0.05 for all); the rates of adverse effects were 15.2% and 63.5% in the TRE and control groups, respectively (P < 0.001); the compliance rates in the TRE and control groups were 85.7% and 74.3%, respectively (P = 0.069).

CONCLUSION: Daily TRE before taking medicine had no significant impact on the patients’ compliance, satisfaction, or H. pylori eradication, but reduced the rate of adverse events.

Review: clinical management of Helicobacter pylori infection in China

Helicobacter pylori (H. pylori) infection has been associated with gastric disorders. The situation of H. pylori infection in China-where a high prevalence of H. pylori infection, a high incidence of gastric cancer, and widespread resistance to clarithromycin, metronidazole, and levofloxacin exist-is quite different from that in Western countries. In order for Chinese clinicians to better manage H. pylori infection, a Chinese Study Group on H. pylori published four consensus reports regarding the management of H. pylori infection in China between 1999 and 2012. The eradication rate with standard triple therapy was <80% in most areas of China. Bismuth is available in China, and bismuth-containing quadruple therapy has been shown to produce a high eradication rate; thus, bismuth quadruple therapy could be recommended both as an initial and as a rescue therapy in China. There is no advantage of sequential therapy over triple therapy in Chinese patients, but the efficacy of concomitant therapy must be studied further. This review introduces the epidemiology, diagnosis, indicators, and therapies for the eradication of H. pylori in China in recent years.

Centralized isolation of Helicobacter pylori from multiple centers and transport condition influences

AIM: To evaluate the efficacy of centralized culture and possible influencing factors.

METHODS: From January 2010 to July 2012, 66452 patients with suspected Helicobacter pylori (H. pylori) infection from 26 hospitals in Zhejiang and Jiangsu Provinces in China underwent gastrointestinal endoscopy. Gastric mucosal biopsies were taken from the antrum for culture. These biopsies were transported under natural environmental temperature to the central laboratory in Hangzhou city and divided into three groups based on their transport time: 5, 24 and 48 h. The culture results were reported after 72 h and the positive culture rates were analyzed by a χ² test. An additional 5736 biopsies from H. pylori-positive patients (5646 rapid urease test-positive and 90 ¹⁴C-urease breath test-positive) were also cultured for quality control in the central laboratory setting.

RESULTS: The positive culture rate was 31.66% (21036/66452) for the patient samples and 71.72% (4114/5736) for the H. pylori-positive quality control specimens. In the 5 h transport group, the positive culture rate was 30.99% (3865/12471), and 32.84% (14960/45553) in the 24 h transport group. In contrast, the positive culture rate declined significantly in the 48 h transport group (26.25%; P < 0.001). During transportation, the average natural temperature increased from 4.67 to 29.14 °C, while the positive culture rate declined from 36.67% (1462/3987) to 24.12% (1799/7459). When the temperature exceeded 24 °C, the positive culture rate decreased significantly, especially in the 48 h transport group (23.17%).

CONCLUSION: Transportation of specimens within 24 h and below 24 °C is reasonable and acceptable for centralized culture of multicenter H. pylori samples.

Hematologic manifestations of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is the most common infection in humans, with a marked disparity between developed and developing countries. Although H. pylori infections are asymptomatic in most infected individuals, they are intimately related to malignant gastric conditions such as gastric cancer and gastric mucosa-associated lymphoid tissue (MALT) lymphoma and to benign diseases such as gastritis and duodenal and gastric peptic ulcers. Since it was learned that bacteria could colonize the gastric mucosa, there have been reports in the medical literature of over 50 extragastric manifestations involving a variety medical areas of specialization. These areas include cardiology, dermatology, endocrinology, gynecology and obstetrics, hematology, pneumology, odontology, ophthalmology, otorhinolaryngology and pediatrics, and they encompass conditions with a range of clear evidence between the H. pylori infection and development of the disease. This literature review covers extragastric manifestations of H. pylori infection in the hematology field. It focuses on conditions that are included in international consensus and management guides for H. pylori infection, specifically iron deficiency, vitamin B₁₂ (cobalamin) deficiency, immune thrombocytopenia, and MALT lymphoma. In addition, there is discussion of other conditions that are not included in international consensus and management guides on H. pylori, including auto-immune neutropenia, antiphospholipid syndrome, plasma cell dyscrasias, and other hematologic diseases.

Current progress toward eradicating Helicobacter pylori in East Asian countries: Differences in the 2013 revised guidelines between China, Japan, and South Korea

New 2013 guidelines on Helicobacter pylori (H. pylori) infection have been published in China, Japan, and South Korea. Like the previous ones, these new guidelines differ between the three countries with regard to the indications for H. pylori eradication, diagnostic methods, and treatment regimens. The most profound change among all of the guidelines is that the Japanese national health insurance system now covers the expenses for all infected subjects up to second-line treatment. This makes the Japanese indications for eradication much wider than those in China and South Korea. With regard to the diagnosis, a serum H. pylori antibody test is not recommended in China, whereas it is considered to be the most reliable method in Japan. A decrease relative to the initial antibody titer of more than 50% after 6-12 mo is considered to be the most accurate method for determining successful eradication in Japan. In contrast, only the urea breath test is recommended after eradication in China, while either noninvasive or invasive methods (except the bacterial culture) are recommended in South Korea. Due to the increased rate of antibiotics resistance, first-line treatment is omitted in China and South Korea in cases of clarithromycin resistance. Notably, the Japanese regimen consists of a lower dose of antibiotics for a shorter duration (7 d) than in the other countries. There is neither 14 d nor bismuth-based regimen in the first-line and second-line treatment in Japan. Such differences among countries might be due to differences in the approvals granted by the governments and national health insurance system in each country. Further studies are required to achieve the best results in the diagnosis and treatment of H. pylori infection based on cost-effectiveness in East Asian countries.

Randomised clinical trial comparing sequential and concomitant therapies for Helicobacter pylori eradication in routine clinical practice

OBJECTIVES

No trial has compared non-bismuth quadruple 'sequential' and 'concomitant' regimens in settings with increasing clarithromycin rates. The study aims to compare the effectiveness and safety of these therapies for Helicobacter pylori treatment.

DESIGN

Prospective randomised clinical trial in 11 Spanish hospitals. Patients naïve to eradication therapy with non-investigated/functional dyspepsia or peptic ulcer disease were included. Randomised (1:1) to sequential (omeprazole (20 mg/12 h) and amoxicillin (1 g/12 h) for 5 days, followed by 5 days of omeprazole (20 mg/12 h), clarithromycin (500 mg/12 h) and metronidazole (500 mg/12 h)), or concomitant treatment (same drugs taken concomitantly for 10 days). Eradication was confirmed with (13)C-urea breath test or histology 4 weeks after treatment. Adverse events (AEs) and compliance were evaluated with questionnaires and residual medication count.

RESULTS

338 consecutive patients were randomised. Mean age was 47 years, 60% were women, 22% smokers and 20% had peptic ulcer. Concomitant and sequential eradication rates were, respectively, 87% vs 81% by intention-to-treat (p=0.15) and 91% vs 86% (p=0.131) per protocol. Respective compliances were 83% vs 82%. Treatment-emergent AEs were reported in 59% of patients (no differences found between treatments). AEs were mostly mild (60%), and average length was 6.1 days, causing discontinuation only in 12 patients. Multivariate analysis: 'concomitant' treatment showed an OR of 1.5 towards better eradication rate in a borderline significance CI (95% CI 0.9 to 2.8).

CONCLUSIONS

Concomitant therapy led to a non-statistically significant advantage (5%) over sequential therapy, coming closer to 90% cure rates. Both therapies showed an acceptable safety profile. ClincialTrials.gov: NCT01273441.

Antibiotic resistance of Helicobacter pylori isolated in the Southeast Coastal Region of China

BACKGROUND

The resistance of Helicobacter pylori (H. pylori) to antibiotics is increasing worldwide, lowering its efficacy in current eradication therapies. This study evaluated H. pylori resistance to antibiotics in the southeast coastal region of China and suggests appropriate alternatives.

MATERIALS AND METHODS

Seventeen thousand seven hundred and thirty one H. pylori strains were collected from eight areas of two provinces in coastal southeast China from 2010 to 2012. The resistance of these strains to six antibiotics was tested using the agar dilution method.

RESULTS

The resistance rates to clarithromycin, metronidazole, levofloxacin, amoxicillin, gentamicin and furazolidone were 21.5, 95.4, 20.6, 0.1, 0.1 and 0.1%, respectively. Double, triple and quadruple antibacterial resistant percentages were 25.5, 7.5 and 0.1%, respectively. A positive association between the resistance to levofloxacin and to clarithromycin was found, but there was a negative correlation in the resistances to levofloxacin and to metronidazole.

CONCLUSIONS

The prevalence of H. pylori resistance to clarithromycin, metronidazole, levofloxacin and multiple antibiotics in coastal southeast China is high. Choice of therapy should be individualized based on a susceptibility test in this region of the country.

Future candidates for indications of Helicobacter pylori eradication: do the indications need to be revised?

Since the discovery of Helicobacter pylori in 1982, the development of several treatment guidelines has allowed a consensus on the indications for H. pylori eradication. Beyond these currently accepted indications, including various upper gastrointestinal disorders and extragastric diseases, a significant amount of new information regarding H. pylori eradication is emerging. Certain types of acute gastritis, such as nodular gastritis, hypertrophic gastritis, Ménétrier's disease, hemorrhagic gastritis, and granulomatous gastritis are reversible after H. pylori eradication. Further, for chronic gastritis, closed-type atrophic gastritis and complete-type intestinal metaplasia appear to be more reversible after H. pylori eradication than open-type atrophic gastritis and incomplete-type intestinal metaplasia. Eradication can also be considered in subjects younger than 40 years who have a family history of gastric cancer and in subjects with long-term medications that might lead to bleeding (antiplatelet agents) or atrophy (proton pump inhibitors). Emerging evidence indicates that H. pylori eradication could be an effective treatment for some extragastric diseases that are unresponsive to conventional therapy. In such conditions, routine screening for eradication of H. pylori has not previously been recommended; a "test-and-treat" approach is suggested in the aforementioned situations. Given that H. pylori eradication is effective when the gastritis is reversible, future indications should be expanded to include acute gastric lesions that show marked improvement upon H. pylori eradication rather than just focusing on chronic gastric lesions. Future indications for H. pylori eradication should focus more on reversible lesions before preneoplastic conditions develop.

Primary antibiotic resistance of Helicobacter pylori isolated from Beijing children

BACKGROUND

The antimicrobials resistance of Helicobacter pylori (H. pylori) was able to sharply decline the eradication rate of H. pylori both in adults and children, but there are limited studies about the primary antibiotic resistance and the related gene mutations, specifically in China.

MATERIALS AND METHODS

The primary resistance to 9 antibiotics of 73 H. pylori strains isolated from gastric biopsies of children recruited at Beijing Children's Hospital was assessed, and the mutations in 23S rRNA gene of 65 macrolide-resistant strains and in gyrA and gyrB of 12 quinolone-resistant strains were investigated.

RESULTS

The resistance rate to clarithromycin, azithromycin, metronidazole, levofloxacin, moxifloxacin, and rifampicin was 84.9%, 87.7%, 61.6%, 13.7%, 15.1%, and 6.8%, respectively. No resistance to amoxicillin, gentamicin, and tetracycline was observed. Dual, triple, and quadruple antibacterial resistant percentage was 46.6% (34/73), 15.1% (11/73), and 2.7% (2/73), respectively. The gene mutation rate of A2142C, A2142G, and A2143G in 23S rRNA gene was 1.5% (1/65), 6.2% (4/65), and 84.6% (55/65), respectively. The detection rate of mutations of Asn87, Asp91, and Met191 in GyrA was 41.7% (5/12), 25% (3/12), and 25% (3/12), respectively.

CONCLUSION

The high prevalence of primary antibiotic resistance was out of expectation in H. pylori strains isolated from the children in Beijing. Antibiotic susceptibility should be made clear before the antibiotic was used in the anti-H. pylori therapy in this population. The A2143G was the most populated mutation in macrolide-resistant strains, and Asn87 and Asp91 of GyrA were the most common mutation points in quinolone resistance strains.

The evolution of Helicobacter pylori antibiotics resistance over 10 years in Beijing, China

OBJECTIVES

To evaluate Helicobacter pylori antibiotics resistance evolution from 2000 to 2009 to amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin and moxifloxacin in Beijing, China.

METHODS

A total of 374 H. pylori strains isolated from 374 subjects who had undergone upper gastrointestinal endoscopy from 2000 to 2009 were collected and examined by E-test method for antibiotics susceptibility.

RESULTS

The average antibiotics resistance rates were 0.3% (amoxicillin), 37.2% (clarithromycin), 63.9% (metronidazole), 1.2% (tetracycline), 50.3% (levofloxacin) and 61.9% (moxifloxacin). Overall resistance to clarithromycin, metronidazole, and fluoroquinolone increased annually (from 14.8 to 65.4%, 38.9 to 78.8%, and 27.1 to 63.5%, in 2000 or 2006-2007 to 2009, respectively). The secondary resistance rates were much higher than primary rates to these antibiotics, which also increased annually in recent 10 years.

CONCLUSIONS

The trend of clarithromycin, metronidazole, and fluoroquinolone resistance of H. pylori increased over time and the resistance to amoxicillin and tetracycline was infrequent and stable in Beijing. Clarithromycin, metronidazole, and fluoroquinolone should be used with caution for H. pylori eradication treatment.

Distribution of gyrA mutations in fluoroquinolone-resistant Helicobacter pylori strains

AIM: To investigate the resistance of Helicobacter pylori (H. pylori) to ciprofloxacin (CIP), levofloxacin (LVX) and moxifloxacin (MOX) in the Beijing area and to elucidate the resistance mechanisms.

METHODS: Seventy-nine H. pylori clinical strains, isolated from patients who had undergone upper gastrointestinal endoscopy in Peking University First Hospital from 2007 to 2009, were tested for their susceptibility to CIP, LVX and MOX using the E-test method. H. pylori strain 26695 was included in the susceptibility testing as a control strain. According to the minimal inhibitory concentration (MIC) values, a strain was classified as resistant to CIP, LVX or MOX when the MIC was > 1 μg/mL. We amplified by polymerase chain reaction (PCR) and sequenced the quinolone resistance-determining regions of the gyrA and gyrB genes from 29 quinolone-resistant and 16 quinolone-susceptible H. pylori strains selected at random.

RESULTS: In this study, the resistance rates of H. pylori to CIP, LVX or MOX were 55.7% (44/79), and the primary resistance rates were 26.6% (21/79). Patients with secondary resistance had received LVX in previous eradication treatments, but not MOX or CIP. Forty-five strains, including 29 CIP, LVX or MOX-resistant strains (MIC: 1.5-32 μg/mL) and 16 susceptible strains, were selected randomly from the 79 strains and used in PCR analysis. Among these 45 strains, 27 resistant strains had mutations in the gyrA gene, including 11 strains with mutations corresponding to Asp-91 (MIC: 2-32 μg/mL), one of which also had a mutation corresponding to Val-150, and 16 strains had mutations at Asn-87 (MIC: 4-32 μg/mL), three of which also had mutations corresponding to Arg-140 or Val-150. In addition, Arg-140, Val-150 or Ala-97 mutations were separately detected in three susceptible strains. Analysis of the gyrB gene showed that one strain of low resistance had a mutation corresponding to Ser-457 that coexisted with an Asp-91 mutation. There was a significant difference in the occurrence of mutations in the gyrA gene between CIP, LVX and MOX-resistant and -susceptible strains (P < 0.05), but 2 resistant strains were found to possess no quinolone resistance-determining region mutations.

CONCLUSION: Resistance is primarily mediated through point mutations in gyrA. Whether other mechanisms are responsible for resistance in strains without mutations in the QRDR should be detected.

Clarithromycin resistance and point mutations in the 23S rRNA gene in Helicobacter pylori isolates from Malaysia

OBJECTIVE

To determine the prevalence of primary clarithromycin resistance amongst Helicobacter pylori (H. pylori) strains in Malaysian patients with gastroduodenal diseases, by using restriction fragment length polymorphism (RFLP) in domain V of 23S rRNA.

METHODS

Gastric biopsies were obtained from H. pylori positive patients undergoing gastroscopy. DNA extraction was followed by PCR amplification using the primers Hp23-1 and Hp23-2 flanking a region of 425bp within the bacterial 23S rRNA peptidyltranferase (Hp23S fragment). Analysis of the 23S rRNA gene mutations is based on the generation of restriction sites for two restriction enzymes: BbsI and BsaI, which correspond to the base substitutions characteristic of clarithromycin resistance from A to G at positions 2142 and 2143, respectively.

RESULTS

Gastric biopsy samples were obtained from 107 patients. A fragment of size 425bp corresponding to that expected from amplification of domain V of 23S rRNA was PCR-amplified from only 105 samples. The amplicon was subsequently subjected to restriction by BbsI and BsaI. Only 1 sample (0.95%) had the BbsI mutation (base substitution at A2142G) and 2 samples (1.90%) the BsaI mutation (base substitution at A2143G). Thus 3 of 105 (2.9%) samples harbored clarithromycin resistant strains.

CONCLUSION

In our experience, PCR-RFLP is a rapid and precise method to detect the resistance of H. pylori to clarithromycin. Using this method, a low prevalence of clarithromycin resistance was detected in our local Malaysian strains. This augurs well for the continued use of clarithromycin as a first line drug in the treatment and eradication of H. pylori infection.

Furazolidone, amoxicillin, bismuth and rabeprazole quadruple rescue therapy for the eradication of Helicobacter pylori

AIM

To compare the efficacy and side effect profiles of three furazolidone and amoxicillin-based quadruple rescue therapies for the eradication of Helicobacter pylori (H pylori).

METHODS

Patients who failed in the H pylori eradication therapy for at least one course were randomly allocated into three groups. Group A received rebaprazole 10 mg + amoxicillin 1 g + furazolidone 100 mg, and bismuth subcitrate 220 mg, twice daily for 1 wk; group B received the same regimen of group A but for 2 wk; and group C received the same regimen of group B, but furazolidone was replaced by furazolidone 100 mg three times daily. To record the side effect profiles at the end of the treatment, H pylori eradication was assessed with (13)C-urea breath test 4 wk after therapy.

RESULTS

Sixty patients were enrolled including 28 males, and 20 patients in each group. The average age of the patients was 49.2 years, ranging from 18 to 84 years. H pylori eradication rates with per-protocol analysis were 82%, 89% and 90% in the three groups, respectively. Side effects were found in 11 patients, including mild dizziness, nausea, diarrhea and increased bowel movement. None of the 11 patients needed treatment for their side effects.

CONCLUSION

One- or two-week furazolidone and amoxicillin-based quadruple rescue therapy with a low dose furazolidone (100 mg bid) for the eradication of H pylori is effective. Extending the antibiotic course to 14 d could improve the eradication rates.