[Acquisition of secondary resistance after failure of a first treatment of Helicobacter pylori infection in children]

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.

Antimicrobial susceptibility testing for Helicobacter pylori isolates from Brazilian children and adolescents: comparing agar dilution, E-test, and disk diffusion

Antimicrobial susceptibility testing for Helicobacter pylori is increasingly important due to resistance to the most used antimicrobials agents. Only agar dilution method is approved by CLSI, but it is difficult to perform routinely. We evaluated the reliability of E-test and disk diffusion comparing to agar dilution method on Helicobacter pylori antimicrobial susceptibility testing. Susceptibility testing was performed for amoxicillin, clarithromycin, furazolidone, metronidazole and tetracycline using E-test, disk-diffusion and agar dilution method in 77 consecutive Helicobacter pylori strains from dyspeptic children and adolescents. Resistance rates were: amoxicillin - 10.4%, 9% and 68.8%; clarithromycin - 19.5%, 20.8%, 36.3%; metronidazole - 40.2%33.7%, 38.9%, respectively by agar dilution, E-test and disk diffusion method. Furazolidone and tetracycline showed no resistance rates. Metronidazole presented strong correlation to E-test (r = 0.7992, p < 0.0001) and disk diffusion method (r=-0.6962, p < 0.0001). Clarithromycin presented moderate correlation to E-test (r = 0.6369, p < 0.0001) and disk diffusion method (r=−0.5656, p < 0.0001). Amoxicillin presented weak correlation to E-test (r = 0.3565, p = 0.0015) and disk diffusion (r=−0.3565, p = 0.0015). Tetracycline presented weak correlation with E-test (r = 0.2346, p = 0.04) and furazolidone to disk diffusion (r=−0.0288, p = 0.8038). E-test presented better agreement with gold standard. It is an easy and reliable method for Helicobacter pylori susceptibility testing. Disk diffusion method presented high disagreement and high rates of major errors.

High Helicobacter pylori resistance to metronidazole and clarithromycin in Brazilian children and adolescents

OBJECTIVE

The aim of the present study was to assess the primary and secondary resistance of Helicobacter pylori strains to clarithromycin, amoxicillin, furazolidone, tetracycline, and metronidazole, the conventional antibiotics presently used in Brazilian children and adolescents.

METHODS

Seventy-seven consecutive H pylori strains, 71 of 77 strains obtained from patients without previous eradication treatment for H pylori infection, and 6 strains from patients in whom previous eradication treatment had failed.

RESULTS

Global rate of resistance was 49.3% (38/77): 40% of strains were resistant to metronidazole, 19.5% to clarithromycin, and 10.4% to amoxicillin. All of the tested H pylori strains were susceptible to furazolidone and tetracycline. Multiple resistance were detected in 18.2% (14/77 patients) of the strains: 6 of 14 (43%) simultaneously resistant to clarithromycin and metronidazole; 5 of 14 (36%) to amoxicillin and metronidazole; 2 of 14 (14%) to amoxicillin, clarithromycin, and metronidazole; and 1 of 14 (7%) to clarithromycin and amoxicillin.

CONCLUSIONS

The high resistance rate to metronidazole and clarithromycin observed in clinical H pylori isolates can exclude these antimicrobials in empirical eradication treatment in Brazil. Otherwise, furazolidone and tetracycline presented no resistance. Properly assessing the risks and benefits, these 2 antimicrobials and their derivatives could be used in empirical eradication schedules, both associated with amoxicillin, which showed a low resistance rate despite its wide use in pediatric patients.

Helicobacter pylori infection in children: management and pharmacotherapy

Helicobacter pylori infection is mainly acquired during childhood: it is recognised as a cause of gastritis and peptic ulcer and it has been classified as a group A carcinogen by the World Health Organisation. The exact mode of transmission is as yet unknown. The aim of this review was to analyse the literature about H. pylori infection in paediatric patients. The large diffusion of H. pylori infection in paediatric patients, the absence of a specific clinical feature, the new non-invasive methods for diagnosis and follow-up, which are still not validated and the different therapeutic schedules have led to the necessity of determining the real clinical outcome in affected children and adolescents. The scope of the review was to identify better eradication therapy and the most important factors in treatment failure. The international literature has shown the importance of culture, antibiograms, the compliance of families and patients and the use of probiotics during triple eradication therapy. The review paid attention to the management, diagnostic techniques and therapy of this infection in paediatric patients.

Antibiotic-resistant Helicobacter pylori strains in Portuguese children

BACKGROUND

Data concerning the effectiveness of Helicobacter pylori eradication regimens based in antibiotic susceptibility testing are scanty in children.

AIMS

To identify the prevalence of antibiotic resistance in H. pylori strains isolated from Portuguese children in 1999-2003; to evaluate eradication rate after antibiotic susceptibility testing-based treatment; and to identify factors associated with resistance and eradication outcome.

METHODS

Included were 109 children with a gastric biopsy culture positive for H. pylori. First treatment (amoxicillin, omeprazole and clarithromycin or metronidazole) was guided by susceptibility testing (E test), and eradication was assessed by [C]urea breath test.

RESULTS

Strains were susceptible to amoxicillin and tetracycline; 39.4% were resistant to clarithromycin, 16.5% to metronidazole and 4.5% to ciprofloxacin. No significant association was found between resistance and sex, age, clinical status, gastritis scores, H. pylori density scores and genotype. Clarithromycin resistance was significantly associated with European origin [odds ratio (OR), 3.9], previous H. pylori empiric therapy (OR 2.8) and amoxicillin minimal inhibitory concentration, > or =0.016 (OR 6.0). Eradication rate after susceptibility-based treatment was 74.7% (59 of 79; 95% confidence interval, 65.9-82.9), and a significant association was found between eradication failure and presence of resistance to 1 or more antibiotics (P < 0.05).

CONCLUSIONS

The prevalence of H. pylori antibiotic resistance was high in the studied population. The modest therapeutic success of clarithromycin and metronidazole susceptibility-based regimens suggests that in addition to resistance, other factors may be involved. The need of susceptibility-based treatment studies in children and of antimicrobial resistance surveillance in high prevalence areas for H. pylori are emphasized.

Inhibidores de la bomba de protones en pediatría

In last years the use in the pediatric area of proton pump inhibitors (omeprazole, lansoprazole, pantoprazole, rabeprazole and esomeprazole) is more often, nevertheless the clinical trials carried out are poor. The aim of this work is to analyse the bibliography published about this kind of drugs in children and to make a revision of its use in the last seven years. More studies with omeprazole and lansoprazole have been developed, to be exact omeprazole and lansoprazole is present in 122 bibliographic appointments and 34 for lansoprazole, which include studies that demonstrate a good tolerance and efficacy. The remaining proton pump inhibitors count with very few studies. The main therapeutic indications were the eradication of Helicobacter pylori, gastroesophageal reflux disease and esophagitis. The number of patients included in the reviewed studies is quite heterogeneous, from 8 to 122 and the age range between 8 days and 17 years. On the other hand, it could be highlighted the non-existence of formulations adapted to the pediatric population and the difficulty of administration specially in the youngest patients. As in many other drugs, it would be necessary to carry out clinical trials in order to determinate the pharmacologic parameters at difference ages, which will allow a safe and effective administration, and its authorization by all Health Authorities.

Infection à Helicobacter pylori et résistance aux antibiotiques

PURPOSE

Seven days triple therapies combining a proton pump inhibitor (PPI) and 2 antimicrobial agents (clarithromycin [C], amoxicillin [A], metronidazole [M]), are recommended for the treatment of Helicobacter pylori infection. The eradication failures have increased these last years, particularly in France (about 30%). They are essentially related to the development of antimicrobial agents resistance, mainly concerning macrolides and nitro-imidazoles.

CURRENT KNOWLEDGE AND KEY POINTS

Primary resistance to clarithromycin is variable, but reaching now about 10% throughout the world and about 20% in France. It reduces the eradication success rate at 25%. The secondary resistance is very high, contra-indicating the use of clarithromycin in second line regimens. Primary resistance to amoxicillin has recently appeared, but remains very low until now, less than 2%, as the tetracyclin (T) resistance. Primary resistance to metronidazole is 3 times higher than macrolides resistance, but its determination is less accurate. Metronidazole resistance reduces eradication rate of about 25%, leading to the use of metronidazole in second line therapy, in increasing the triple therapy duration at 14 days (PPI-A-M), or in combination with quadruple therapy (Bismuth-PPI-T-M). Other rescue-treatments are efficacious, based on ranitidine bismuth citrate combined regimens or on rifabutine (R) based regimens (PPI-A-R).

FUTURE PROSPECTS AND PROJECTS

The recent knowledge of the mutations mainly responsible for H. pylori resistance to antimicrobial agents now allows the development of detection methods based on the study of bacterial DNA. These methods have been validated for clarithromycin and should favour in the near future the determination of resistance by the use of biopsy culture or directly on the gastric biopsy.

Helicobacter pylori infection in pediatrics

In the past year the main interest was focused on the role of family for transmission of Helicobacter pylori to children; the evaluation of noninvasive diagnostic tests, especially in young children; extra-intestinal clinical manifestations; the lack of consensus on treatment; and the problem of high resistance of the microorganism to antibiotics.