Time trends of Helicobacter pylori resistance to antibiotics in children living in Vienna, Austria

Global prevalence of Helicobacter pylori antibiotic resistance among children in the world health organization regions between 2000 and 2023: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori infection causes gastritis, peptic ulcers, and gastric cancer. The infection is typically acquired in childhood and persists throughout life. The major impediment to successful therapy is antibiotic resistance. This systematic review and meta-analysis aimed to comprehensively assess the global prevalence of antibiotic resistance in pediatric H. pylori infection.

METHODS

We performed a systematic search of publication databases that assessed H. pylori resistance rates to clarithromycin, metronidazole, levofloxacin, amoxicillin, and tetracycline in children. The WHO region classification was used to group pooled primary and secondary resistance estimates along with 95% confidence interval (CI). H. pylori antibiotic resistance rates were retrieved and combined with odds ratios (95% CI) to investigate the global prevalence and temporal trends. Subgroup analysis of the prevalence of antibiotic resistance was conducted by country, age groups, and susceptibility testing methods.

RESULTS

Among 1417 records obtained initially, 152 studies were selected for eligibility assessment after applying exclusion criteria in multiple steps. Ultimately, 63 studies involving 15,953 individuals were included comprising data from 28 countries in 5 WHO regions. The primary resistance rates were metronidazole 35.3% (5482/15,529, 95% CI: 28.7-42.6), clarithromycin 32.6% (5071/15,555, 95% CI: 27.7-37.9), tetracycline 2.1% (148/7033, 95% CI: 1.3-3.6), levofloxacin 13.2% (1091/8271, 95% CI: 9.3-18.4), and amoxicillin 4.8% (495/10305, 95% CI: 2.5-8.8). Raising antibiotic resistance was detected in most WHO regions.

CONCLUSIONS

The escalating trend of H. pylori antibiotic resistance in children warrants urgent attention globally. National and regional surveillance networks are required for antibiotic stewardship in children infected with H. pylori.

Helicobacter pylori resistance to clarithromycin and fluoroquinolones in a pediatric population in Turkey: A cross-sectional study

BACKGROUND

Helicobacter pylori antimicrobial resistance is gradually increasing around the world. However, there are a limited number of studies reporting on this issue in the pediatric population. In this study, we aimed to determine H pylori resistance to clarithromycin and fluoroquinolones in the pediatric patients living in Kırıkkale province that were detected with H pylori in gastric biopsies. Moreover, we also aimed to investigate the concordance between the histopathologic and molecular methods used in the diagnosis of H pylori infection.

MATERIALS AND METHODS

Patients aged 2-18 years who had a history of epigastric pain and/or nausea persisting for longer than 1 month underwent upper gastrointestinal endoscopy. Biopsies were taken from the gastric antral mucosa. In the samples detected with H pylori in the histopathologic examination, the presence of H pylori and H pylori resistance to clarithromycin and fluoroquinolones was investigated using the GenoType HelicoDR test which allows the detection of wild-type and mutant genes. The strains detected with more than one mutant gene are defined as hetero-resistant strains.

RESULTS

The 93 patients that underwent DNA extraction and amplification included 68 (73.1%) girls and 25 (26.9%) boys with a median age of 15 ± 2.62 (range 6-17) years. The overall concordance for the diagnosis of H pylori infection between histopathology and PCR was 94%, and H pylori resistance to clarithromycin and fluoroquinolones was 27% and 15%, respectively.

CONCLUSIONS

The high H pylori resistance to clarithromycin and fluoroquinolones among the pediatric patients in our region implicates that the antibiotic sensitivity of strains should be studied prior to administration in accordance with the recommendations provided in the guidelines. Moreover, the presence of hetero-resistant strains in our patients may be a reason for treatment failure.

Helicobacter pylori antimicrobial resistance in a pediatric population

BACKGROUND

The increasing prevalence of Helicobacter pylori (H. pylori) antimicrobial resistance, primarily for clarithromycin decreases the success of treatment. The aim of this study is to determine the local pattern of first-line antimicrobials resistance and the eradication rate.

MATERIAL AND METHODS

Prospective cohort study of H. pylori infected patients (positive histological or cultural exams) treated at Centro Materno-Infantil do Norte from January of 2013 to October of 2017. Susceptibility to 4 antibiotics: amoxicilin, metronidazole, clarithromycin, and levofloxacin were analyzed by E-test (phenotypic resistance). The E-test was chosen because it is simple and cost-effective for routine susceptibility testing. Point mutations that confer clarithromycin resistance were surveyed (genotypic resistance). Eradication of H. pylori infection was defined by a negative urea breath test or fecal antigen 6-8 weeks after the end of treatment.

RESULTS

Of a total of 74 H. pylori infected patients, 16 were excluded because they had previous H. pylori treatment or severe systemic disease. Median age of infection cases was 15 years (3-17 years). Eradication regimen used in all patients combined the use of 3 antibiotics (amoxicillin and metronidazole or clarithromycin) and proton pump inibhitor for 14 days and was tailored according antimicrobial susceptibility. 79.5% of the patients completed the treatment. The resistance rate for metronidazole and clarithromycin was 3.3% and 23.3%, respectively. There was no resistance for amoxicilin and levofloxacin. The rate of genotypic resistance to clarithromycin was 37.2%. The eradication rate was 97.8%.

CONCLUSIONS

The authors found a high resistance rate of H. pylori for clarithromycin in this northern portuguese pediatric center. This factor should determine a change in local current treatment, contraindicating the use of clarithromycin as a first-line treatment for H. pylori infection in children. The high eradication rate maybe explained for the eradication treatment tailored according antimicrobial susceptibility.

Antibiotic Resistance of Helicobacter pylori in Iranian Children: A Systematic Review and Meta-Analysis

Antibiotic therapy for children infected with Helicobacter pylori is important. However, resistance to antibiotics is one of the main causes of treatment failure. This study was designed to evaluate the prevalence pattern of antibiotic resistance of H. pylori in Iranian children using a systematic review and meta-analysis of literature. A computerized search (until June 10, 2017) using related keywords in the national and international databases was performed. A total of 261 original articles on antibiotic resistance of H. pylori in Iranian children were collected. After screening for inclusion and exclusion criteria, six eligible articles were included in the meta-analysis. Resistance rates of H. pylori to different antibiotics were as follows: metronidazole: 71%, clarithromycin: 12.2%, amoxicillin: 20.4%, tetracycline: 8.4%, ampicillin: 21.4%, rifampin: 28.6%, furazolidone: 8.4%, ciprofloxacin: 16.2%, azithromycin: 19%, erythromycin: 15.3%, and nitrofurantoin: 0%. The prevalence of H. pylori resistance to metronidazole, amoxicillin, ampicillin, and rifampin among Iranian children was high. Therefore, a careful monitoring of antibiotic resistance to select the best treatment options and prevent treatment failure is required. Although resistance to some antibiotics such as clarithromycin, tetracycline, furazolidone, and ciprofloxacin was less prevalent, frequent consumption of these drugs in children should be controlled owing to their known adverse events.

Antibacterial resistance and the success of tailored triple therapy in Helicobacter pylori strains isolated from Slovenian children

BACKGROUND

Primary Helicobacter pylori (H. pylori) infection occurs predominantly in childhood. Antimicrobial resistance is the leading cause for H. pylori eradication failure. The aims of this study were (i) to establish for the first time the antimicrobial resistance of H. pylori strains in infected Slovenian children not previously treated for H. pylori infection and (ii) to evaluate the effectiveness of tailored triple therapy, assuming that eradication rate with tailored triple therapy will be >90%.

METHODS

Data on all treatment-naive children 1-18 years old and treated for H. pylori infection according to susceptibility testing were retrospectively analyzed. All relevant clinical information and demographical information were retrospectively collected from the hospital information systems and/or patients' medical documentation.

RESULTS

The inclusion criteria were met by 107 children (64.5% girls) with a median age of 12.0 years (range 2.0-17.6 years). Primary antimicrobial resistance rates of H. pylori were 1.0% to amoxicillin (AMO), 23.4% to clarithromycin (CLA), 20.2% to metronidazole (MET), 2.8% to levofloxacin (LEV), and 0.0% to tetracycline (TET). Dual resistances were detected to CLA and MET in 11.5% (n=12) of strains, to CLA and LEV in 2.8% (n=3), and to MET and LEV in 2.9% (n=3). Results of treatment success were available for 71 patients (66.2% girls). Eradication of H. pylori was evaluated using the 13C-urea breath test, monoclonal stool antigen test or in some cases with repeated upper GI endoscopy with histology and cultivation/molecular tests. Eradication was achieved in 61 of 71 (85.9%) patients.

CONCLUSIONS

The primary resistance rates of H. pylori to CLA and MET in Slovenia are high. Our data strongly support the fact that in countries with high prevalence of resistant H. pylori strains susceptibility testing and tailored therapy is essential.

Helicobacter pylori from Peptic Ulcer Patients in Uganda Is Highly Resistant to Clarithromycin and Fluoroquinolones: Results of the GenoType HelicoDR Test Directly Applied on Stool

Background

Around 70–90% of peptic ulcer disease (PUD) is due to Helicobacter pylori and requires treatment with antimicrobials to which these bacteria are susceptible. Common H. pylori diagnostic tests do not provide drug susceptibility data. Using the GenoType HelicoDR PCR test designed for gastric biopsies for simultaneous detection of H. pylori and its resistance to clarithromycin (CLA)/fluoroquinolones (FLQ), we present evidence for stool as an optional test specimen and also provide data on prevalence of H. pylori resistance to CLA and FLQ in Uganda.

Methods

Stool from 142 symptomatic PUD patients at three hospitals in Kampala was screened for H. pylori using a rapid antigen test. The GenoType HelicoDR test was run on all H. pylori antigen positives to determine PCR positivity and resistance to CLA/FLQ.

Results

Thirty-one samples (22%) were H. pylori antigen positive, and 21 (68%) of these were H. pylori PCR positive. Six of the 21 (29%) were resistant to CLA and eight to FLQ (42%), while two gave invalid FLQ resistance results.

Conclusion

Stool is a possible specimen for the GenoType HelicoDR test for rapid detection of H. pylori and drug resistance. In Uganda, Helicobacter pylori is highly resistant to CLA and FLQ.

Increasing metronidazole and rifampicin resistance of Helicobacter pylori isolates obtained from children and adolescents between 2002 and 2015 in southwest Germany

BACKGROUND

Increasing antibiotic resistance has been reported for Helicobacter pylori, but data on the prevalence of antibiotic resistance of H. pylori in pediatric patients and the development of resistance over time are sparse.

METHODS

Data for 610 H. pylori isolates obtained between 2002 and 2015 from gastric biopsies of 582 (mainly treatment-naïve) pediatric patients from southwest Germany were analyzed retrospectively regarding the antibiotic susceptibility determined by Etest and patients' characteristics.

RESULTS

Overall resistance to metronidazole, clarithromycin, and rifampicin was 28.7%, 23.2%, and 13.3%, respectively, while resistance to amoxicillin was rare (0.8%). Simultaneous resistance to metronidazole and clarithromycin was observed for 7.7% of the isolates, and 2.3% were resistant to metronidazole, clarithromycin, and rifampicin. Differences between primary vs secondary resistance existed for metronidazole (24.7% vs 38.8%, P=.01) and clarithromycin (17.2% vs 54.1%, P=.0001). From 2002-2008 to 2009-2015, resistance to metronidazole increased from 20.8% to 34.4% (P=.003) and to rifampicin from 3.9% to 18.8% (P=.0001); this was not associated with increased numbers of patients previously treated for H. pylori infection in the second study period. In contrast, resistance to clarithromycin did not change significantly over time. Resistance was not associated with age, sex, or family origin in Europe.

CONCLUSIONS

The considerable antibiotic resistance of H. pylori isolates argues for standard antibiotic susceptibility testing of H. pylori in pediatric patients prior to the initiation of antibiotic therapy.

Primary Antibiotic Resistance to Helicobacter pylori Strains Isolated From Children in Northern Iran: A Single Center Study

Background:

Initial resistance to antibiotics is the main reason for the failure of Helicobacter pylori (H. pylori) eradication in children.

Objectives:

As we commonly face high antibiotic resistance rates in children, we aimed to determine the susceptibility of H. pylori to common antibiotics.

Patients and Methods:

In this cross-sectional in vitro study, 169 children younger than 14 years with clinical diagnosis of peptic ulcer underwent upper gastrointestinal endoscopy. Biopsy specimens from stomach and duodenum were cultured. In isolated colonies, tests of catalase, urease, and oxidase as well as gram staining were performed. After confirming the colonies as H. pylori, the antibiogram was obtained using disk diffusion method.

Results:

Culture for H. pylori was positive in 12.3% of the specimens, urease test in 21.3%, serological test in 18.9% and stool antigen test was positive in 21.9%. We could show high specificity but moderate sensitivity of both histological and H. pylori stool antigen tests to detect H. pylori. The overall susceptibility to metronidazole was 42.9%, amoxicillin 95.2%, clarithromycin 85.7%, furazolidone 61.9%, azithromycin 81.0%, and tetracycline 76.2% with the highest resistance to metronidazole and the lowest to clarithromycin.

Conclusions:

In our region, there is high resistance of H. pylori to some antibiotics including metronidazole and furazolidone among affected children. To reduce the prevalence of this antibiotic resistance, more controlled use of antibiotics should be considered in children.

Helicobacter pylori Infection in Children. Antimicrobial Resistance and Treatment Response

BACKGROUND

The aim of this study was to determine the appropriateness of the recent recommendations for managing Helicobacter pylori infection in children in a university hospital in Southern Europe. Antimicrobial resistance and response to eradication therapy were also determined.

MATERIALS AND METHODS

The presence of H. pylori was studied in 143 children: by gastric biopsy culture (GBC), (13)C-urea breath test (UBT) and stool antigen immunochromatography test (SAIT) in 56 children; by GBC and UBT in 20, by GBC and SAIT in 18, and by GBC alone in 49. Antimicrobial susceptibility was determined by E-test. Infection was defined as a positive culture or positivity in both UBT and SAIT. Disease progression was studied in 118 patients. First evaluation of symptoms was carried out at 3-6 months after diagnosis and/or after treatment of the infection.

RESULTS

H. pylori was detected in 74 from the 143 children analyzed (100% GBC positive, 98.1% UBT positive, and 58.1% SAIT positive). The main symptom was chronic abdominal pain (n = 121). Macroscopic antral nodularity was observed in 29.7% of infected patients and in 5.8% of uninfected patients, respectively. Resistance to clarithromycin and metronidazole was found in 34.7 and 16.7%, respectively. Eradication when susceptible antimicrobials were used occurred in 78.7% (48/61) versus 37.5% (3/8) when the treatment included a drug with resistance (p = .024). In patients with recurrent abdominal pain, symptoms resolved in 92.9% (39/42) patients with HP eradication versus 42.9% (6/14) without HP eradication (p < .001).

CONCLUSION

Treated patients often failed to meet the criteria established in the guidelines for H. pylori diagnostic screening and treatment because most of them had only recurrent abdominal pain, but remission of their symptoms was associated with H. pylori eradication.

Primary Antimicrobial Susceptibility Changes in Children with Helicobacter pylori Infection over 13 Years in Northern Italy

The eradication therapy of Helicobacter pylori (H. pylori) infection is still a challenge for gastroenterologists. One of the main causes of failure in H. pylori eradication is the antibiotic resistance mainly to clarithromycin. Culture from biopsies is maybe the most used method among the antimicrobial susceptibility techniques. In this study, we compared the antimicrobial susceptibility changes in children with H. pylori infection over 13 years and we confirmed that clarithromycin resistance has been increased (16% versus 26%) though with no statistically signficant value. Therefore, clarithromycin should not be used in empiric treatment of H. pylori eradication therapy in children, but its use should be limited only to children with known antimicrobial susceptibility. On the other hand, metronidazole resistance has decreased over this time period in statistically significant manner (56% versus 33%, p = 0.014). Furthermore, ampicillin resistance has been confirmed to be very rare (3% versus 0%) in children with H. pylori infection. In conclusion, in H. pylori infection, if we do not know the antibiotic susceptibility of patients, we should recommend an eradication therapy based on the local distribution of antibiotic resistance rates trying to limit the therapeutic failures.

Sequential therapy versus standard triple therapy for Helicobacter pylori eradication in children: any advantage in clarithromycin-resistant strains?

OBJECTIVE

There has been a marked decrease in the eradication rates of Helicobacter pylori infection with standard triple therapy worldwide. Hence, sequential therapy has gained attention as a promising treatment during the last few years. This study was carried out to compare the efficacy of sequential versus standard triple therapy in the context of clarithromycin (CLA) resistance.

MATERIALS AND METHODS

In this study, children between 3 and 18 years of age, who had documented H. pylori infection, were randomized to receive either standard triple or sequential therapy. H. pylori eradication was ascertained using the C-urea breath test 4-6 weeks after the completion of the treatment. Real-time PCR was performed on gastric biopsy samples for assessment of CLA resistance.

RESULTS

In all, 148 children (median age: 12.18±3.51 years) were recruited randomly into the study. The intention-to-treat eradication rates were 50% (37/74) for the sequential treatment group and 52.7% (39/74) for the standard triple treatment group (P=0.87). A total of 136 children completed the study. The per-protocol eradication rates were 56% (37/66) and 55.7% (39/70) for sequential and standard triple therapy groups, respectively. CLA resistance was assessed and 113 children were included in the final analysis. Of 113 participants, 53 were in the sequential treatment group and 60 were in the standard triple treatment group. The success rates of the respective therapies (29/53=54.7% in sequential, 33/60=55% in standard therapy) were similar (P=0.98). CLA resistance was detected in 29 (25.7%) of the patients. Eradication rates with sequential therapy in CLA susceptible and resistant cases were 60.5% (23/38) and 40% (6/15), respectively (P=0.23). The corresponding figures for the standard triple treatment group were 63% (29/46) and 28.6% (4/14) (P=0.033). Although a higher eradication rate was observed in CLA-resistant cases with sequential therapy, the difference did not reach statistical significance (P=0.69).

CONCLUSION

In this study, standard triple treatment failed to eradicate H. pylori infection in the majority of the children, and sequential therapy offered only a small advantage over standard triple therapy in the eradication of CLA-resistant strains.

Antibiotics resistance of Helicobacter pylori and treatment modalities in children with H. pylori infection

Pediatric infection with Helicobacter pylori may occur early in childhood and persist lifelong. Global pediatric clinical studies have reported a decreasing tendency in the overall rate of H. pylori eradication. In pediatric patients with H. pylori infection, pediatric patients with peptic ulcer, and the first-degree relatives of patients with a history of gastric cancer, it is commonly recommended that H. pylori strains be eradicated. Antibiotic drug resistance to H. pylori, which has been reported to vary widely between geographic regions, is mainly associated with treatment failure in these patients. It is therefore imperative that the antibiotic resistance rates of H. pylori in children and adolescents be meticulously monitored across countries and throughout geographic regions. This paper particularly focuses on the antibiotic drug resistance of H. pylori and the thearpy of pediatric H. pylori infection cases.

Second and third line treatment options for Helicobacter pylori eradication

Helicobacter pylori is a highly successful bacterium with a high global prevalence and the infection carries significant disease burden. It is also becoming increasingly difficult to eradicate and the main reason for this is growing primary antibiotic resistance rates in a world where antibiotics are frequently prescribed and readily available. Despite knowing much more about the bacterium since its discovery, such as its genomic makeup and pathogenesis, we have seen declining treatment success. Therefore, clinicians today must be prepared to face one, two or even multiple treatment failures, and should be equipped with sufficient knowledge to decide on the appropriate salvage therapy when this happens. This article discusses the factors contributing to treatment failure and reviews the second and third-line treatment strategies that have been investigated. Established empiric second line treatment options include both bismuth based quadruple therapy and levofloxacin based triple therapy. Antibiotic testing is recommended prior to initiating third line treatment. In the event that antibiotic susceptibility testing is unavailable, third line treatment options include rifabutin, rifaximin and sitafloxacin based therapies.

Changing pattern of antibiotic resistance of Helicobacter pylori in children during 20 years in Jinju, South Korea

BACKGROUND

The antimicrobial resistance capability of Helicobacter pylori is one of the critical factors in the failure to treat this pathogen. The purpose of this study was to investigate the changing pattern of primary antibiotic resistance rates in children in the southern central part of South Korea from 1990 to 2009.

METHODS

H. pylori strains were isolated from children who had undergone upper endoscopy at Gyeongsang National University Hospital, including 58 children from 1990-1994 and 33 children from 2005-2009. The susceptibility of H. pylori strains to erythromycin, clarithromycin, azithromycin, amoxicillin, tetracycline, metronidazole, furazolidone, levofloxacin, ciprofloxacin, moxifloxacin, and rifabutin was tested using the serial twofold agar dilution method.

RESULTS

The resistance rate to erythromycin increased significantly from 13.8% in 1990-1994 to 33.3% in 2005-2009 (P = 0.032). Clarithromycin resistance increased from 6.9% to 18.2%. Metronidazole resistance decreased from 32.8% to 27.3%. The minimum inhibitory concentration of azithromycin and erythromycin showed definite shifts to higher concentrations in 2005-2009 compared with the strains sampled in 1990-1994 (P = 0.021 and P = 0.025, respectively). The frequency of both macrolide- and metronidazole-resistant strains was 13.8% in 1990-1994 and 15.2% in 2005-2009. No associations were detected between multidrug-resistant strains and the two study periods.

CONCLUSIONS

The antibiotic resistance rates of H. pylori in Jinju had a different pattern to other regions. The antibiotic resistance rates of H. pylori showed geographic variation, and local data should be provided as a guideline for treating H. pylori infection.

Evolution of Helicobacter pylori susceptibility to antibiotics during a 10-year period in Lithuania

The study evaluated the changes in the prevalence of Helicobacter pylori strains with primary resistance to antibiotics during the last 10 years in Lithuania. H. pylori susceptibilities to antibiotics were tested in 89 patients in 1998, in 81 patients in 2001 and in 90 patients in 2007/2008. Susceptibility to metronidazole, clarithromycin, amoxicillin and tetracycline was tested using E-test or agar dilution method. Susceptibility to ciprofloxacin was only tested in 2007/2008. Data about utilization of all authorized and available on market macrolides and clindamycin in Lithuania during 2003-2007 were evaluated using WHO ATC/DDD methodology. A total of 260 H. pylori strains cultured from untreated adult patients were investigated. Primary resistance rates (1998, 2001 and 2007/2008) for metronidazole were 24.7%, 33.3%, and 35.6%, for clarithromycin 1.1%, 3.7%, and 3.3% and for tetracycline 0%, 2.5% and 0% respectively. No cases of amoxicillin resistance have been detected. The resistance rate for ciprofloxacin was 5.6% in 2007/2008. Data of total macrolides and clarithromycin utilization in Lithuania revealed that despite an increase of consumption of these drugs in Lithuania during 2003-2007 in 1.5 times, the total macrolide consumption remains one of the lowest in Europe. We have not observed any significant changes in the susceptibility of H. pylori to the most widely used antibiotics during the recent 10-year period. The low resistance rate to clarithromycin might be related to the policy to avoid use of macrolides as first-line treatment for pulmonary and other infections.

Levofloxacin/amoxicillin-based schemes vs quadruple therapy for Helicobacter pylori eradication in second-line

Worldwide prevalence of Helicobacter pylori (H. pylori) infection is approximately 50%, with the highest being in developing countries. We compared cure rates and tolerability (SE) of second-line anti-H. pylori levofloxacin/amoxicillin (LA)-based triple regimens vs standard quadruple therapy (QT). An English language literature search was performed up to October 2010. A meta-analysis was performed including randomized clinical trials comparing 7- or 10-d LA with 7-d QT. In total, 10 articles and four abstracts were identified. Overall eradication rate in LA was 76.5% (95% CI: 64.4%-97.6%). When only 7-d regimens were included, cure rate was 70.6% (95% CI: 40.2%-99.1%), whereas for 10-d combinations, cure rate was significantly higher (88.7%; 95% CI: 56.1%-109.9%; P < 0.05). Main eradication rate for QT was 67.4% (95% CI: 49.7%-67.9%). The 7-d LA and QT showed comparable efficacy [odds ratio (OR): 1.09; 95% CI: 0.63-1.87], whereas the 10-d LA regimen was significantly more effective than QT (OR: 5.05; 95% CI: 2.74-9.31; P < 0.001; I(2) = 75%). No differences were reported in QT eradication rates among Asian and European studies, whereas LA regimens were more effective in European populations (78.3% vs 67.7%; P = 0.05). Incidence of SE was lower in LA therapy than QT (OR: 0.39; 95% CI: 0.18-0.85; P = 0.02). A higher rate of side effects was reported in Asian patients who received QT. Our findings support the use of 10-d LA as a simple second-line treatment for H. pylori eradication with an excellent eradication rate and tolerability. The optimal second-line alternative scheme might differ among countries depending on quinolone resistance.

Antibiotic resistance of Helicobacter pylori in pediatric patients -- 10 years' experience

The aim of this study was to assess the pattern of evolution of resistance to antibiotics in Helicobacter pylori isolated from children who underwent upper endoscopy with antral biopsy during a 10-year period (2001-2010). We retrospectively analyzed data of all children (n = 3,008) who underwent upper endoscopy during the observed period at the Children's Hospital Zagreb, a university tertiary medical center. We calculated the rate, antibiotic susceptibility and risk factors for the H. pylori infection in our cohort. Antral biopsy was performed in 2,313 (76.89%) patients. Altogether, 382 (16.51%) children had positive biopsy for H. pylori (histology and/or culture). There was no significant difference in the incidence of H. pylori during 10 years of observation (p = 0.21). Infected children compared to non-infected group were older (p = 0.005), and had more often antral nodularity (p < 0.0001), and duodenal ulcer (p = 0.002). Altogether, 22.4% of treatment-naïve patients had strains resistant to tested antibiotics: majority to azithromycin (17.9%), followed by clarithromycin (11.9%), metronidazole (10.1%) and amoxicillin (0.6%). In the eradication failure group, 9/11 of children had strains resistant to tested antibiotics, mostly to metronidazole (7/11), followed by azithromycin (3/11) and clarithromycin (1/11). No correlation was found between age or gender and antibiotic resistance (p = 0.32, for both). In conclusion, our data strongly support current guidelines which recommend antibiotic susceptibility testing prior to eradication therapy. Based on our results we recommend the use of amoxicillin-metronidazole-based regimen as the first-line therapy in our study population.

Monitoring of antibiotic resistance rates of Helicobacter pylori in Austrian children, 2002-2009

We retrospectively studied antibiotic resistance rates of H. pylori and their temporal changes in children. Resistance rates were 21.6% for both clarithromycin and metronidazole. There was no overall difference between children with or without migrational background. Resistance rates increased over time, and patients without migrational background showed a significant increase in metronidazole resistance. Our study emphasizes antibiotic resistance monitoring of H. pylori in children.

Helicobacter pylori in pediatrics

This article reviewed the important publications on Helicobacter pylori research with children between April 2010 and March 2011. The most interesting studies in the last year lend further weight to the evidence for vertical transmission of H. pylori. The discovery of a potential role for jhp0562, the gene which encodes for the cell envelope protein glycosyltransferase, in the progression to peptic ulcer disease is also very interesting as it may provide a novel way to distinguish children at risk of peptic ulcer disease from those who are not, and so determine those who requires treatment to eradicate H. pylori. The rise in non-H. pylori-associated ulcers and erosions continues to be reported with no apparent risk factors for these ulcers identified to date. High levels of treatment failure continue to be reported, and there remains an urgent need for more effective treatment regimes for children.

Helicobacter pylori eradication rates in children upon susceptibility testing based on noninvasive stool polymerase chain reaction versus gastric tissue culture

BACKGROUND AND OBJECTIVES

In children with clarithromycin-resistant Helicobacter pylori, clarithromycin-containing therapies often fail. The present study aimed to assess the outcome of tailored therapy upon noninvasive versus invasive H pylori susceptibility testing.

PATIENTS AND METHODS

A retrospective cohort study was conducted in a pediatric outpatient clinic located in a region where H pylori clarithromycin resistance is highly prevalent. Between June 2007 and September 2009, 96 infected children (mean age 10.8 years), naïve to H pylori eradication treatment, were prescribed triple eradication therapies. These therapies were individually tailored upon susceptibility testing performed either noninvasively using stool polymerase chain reaction (stool PCR group) or invasively using endoscopy, biopsy, and culturing of gastric biopsies (gastric biopsy group). Eradication was defined by negative results upon noninvasive testing including stool PCR at least 5 weeks after the end of treatment.

RESULTS

H pylori was eradicated in 43 of 55 stool PCR group versus 30 of 41 gastric biopsy group children (78.2% vs 73.2%, P = 0.63). Of those H pylori strains with pretherapeutic clarithromycin susceptibility, 78.8% were eradicated in the stool PCR group and 69.2% in the gastric biopsy group (P = 0.41) following clarithromycin-containing therapy; clarithromycin resistance was acquired by 4.1% of strains in the former group versus 12% in the latter (P = 0.33).

CONCLUSIONS

Stool PCR is as effective as the invasive approach of H pylori susceptibility testing for targeting resistance-guided eradication treatments in children. Furthermore, stool PCR is a useful tool for tracking the emergence of clarithromycin resistance following eradication treatment.

High Helicobacter pylori resistance to metronidazole but zero or low resistance to clarithromycin, levofloxacin, and other antibiotics in Malaysia

OBJECTIVE

Bacterial resistance to antibiotics is the single most important determinant of treatment success. The objective of this study was to determine the prevalence of Helicobacter pylori resistance to clarithromycin, amoxicillin, metronidazole, tetracycline, levofloxacin, rifabutin, and furazolidone in our local bacterial strains.

METHODS

Samples from consecutive ninety patients were obtained for culture and sensitivity testing. Resistance to individual antibiotics were tested using the E-test and MIC(90) read from the strips. Resistance to rifampicin and nitrofurantoin were used as a surrogate for rifabutin and furazolidine.

RESULTS

There was a high prevalence of resistance to metronidazole 68/90 (75.5%). No male (34/45 (75.5%) versus female (35/45 (77.7%) difference in frequency of metronidazole resistance was noted (p = 1.000). There was zero resistance (0) to clarithromycin, levofloxacin, amoxicillin, and nitrofurantoin/furazolidone. Resistance to rifampicin/rifabutin was for breakpoints of 1 and 4 μg/mL of 14.4 and 2.2% respectively.

CONCLUSIONS

Although there was high bacterial resistance to metronidazole, the absence of resistance particularly to the key antibiotics used in H. pylori eradication therapy: clarithromycin and levofloxacin is reassuring to note. Continued monitoring of antibiotic resistance should be carried out.

Multicenter survey of routine determinations of resistance of Helicobacter pylori to antimicrobials over the last 20 years (1990 to 2009) in Belgium

We analyzed the rates of antimicrobial resistance of Helicobacter pylori strains isolated from patients from 1990 to 2009 and identified risk factors associated with resistance. Gastric biopsy specimens were collected from several digestive disease centers in Brussels, Belgium. We routinely performed antimicrobial susceptibility testing for clarithromycin (CLR), metronidazole, amoxicillin, tetracycline, and ciprofloxacin. Evaluable susceptibility testing was obtained for 9,430 strains isolated from patients who were not previously treated for Helicobacter pylori infection (1,527 isolates from children and 7,903 from adults) and 1,371 strains from patients who were previously treated (162 isolates from children and 1,209 from adults). No resistance to amoxicillin was observed, and tetracycline resistance was very rare (<0.01%). Primary metronidazole resistance remained stable over the years, with significantly lower rates for isolates from children (23.4%) than for isolates from adults (30.6%). Ciprofloxacin resistance remained rare in children, while it increased significantly over the last years in adults. Primary clarithromycin resistance increased significantly, reaching peaks in 2000 for children (16.9%) and in 2003 for adults (23.7%). A subsequent decrease of resistance rates down to 10% in both groups corresponded to a parallel decrease in macrolide consumption during the same period. Multivariate logistic regression revealed that female gender, age of the patient of 40 to 64 years, ethnic background, the number of previously unsuccessful eradication attempts, and the different time periods studied were independent risk factors of resistance to clarithromycin, metronidazole, and ciprofloxacin. Our study highlights the need to update local epidemiological data. Thus, the empirical CLR-based triple therapy proposed by the Maastricht III consensus report remains currently applicable to our population.

Antibiotic resistance of Helicobacter pylori in Mazandaran, North of Iran

BACKGROUND

The aim of this study was to investigate the prevalence of resistances in Helicobacter pylori against commonly used antibiotics including metronidazole, clarithromycin, amoxicillin, and tetracycline in Iranian patients.

METHODS

H. pylori isolates were collected from gastric biopsies from patients referred for upper gastrointestinal endoscopy at Tooba Medical Center, Sari, Iran, from 2007 to 2010. None of them had been using antibiotics for at least 8 months. H. pylori was identified based on morphological shape and positive biochemical tests for catalase, oxidase, and urease activity. Antibiotic resistance for metronidazole, clarithromycin, amoxicillin, and tetracycline was investigated by using epsilometer test. Resistance was defined by minimal inhibitory concentration (MIC) > 0.5 mg/L for amoxicillin (AMX), >4 mg/L for tetracycline (TET), >8 mg/L for metronidazole (MTZ), and >1 mg/L for clarithromycin (CLR).

RESULTS

Strains were collected from 132 patients, mean age 45.8 years, 52 (39%) were women. Patients had diverse diagnoses: gastritis 42 (31.8%), duodenal ulcer 45 (34%), gastric cancer 15 (11.3%), or gastric ulcer 30 (22.7%). The prevalences of resistance of H. pylori strains isolated from the patients were 73.4% for metronidazole, 30% for clarithromycin, 6.8% for amoxicillin, and 9% for tetracycline. Twenty-eight (21.2%) were double resistant to MTZ-CLR, 16 (12.1%) showed triple resistance to MTZ-CLR-AMX, and 8 (6%) were resistant to all four tested antibiotics (MTZ-CLR-AMX-TET). No associations were detected between multiple resistant strains and clinical manifestations (p > .05).

CONCLUSIONS

The prevalence of H. pylori antibiotic resistance to metronidazole and clarithromycin was high in Iran consistent with the reported low success rates for H. pylori treatment in this country.