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

Detection of A2143G, A2142C, and A2142G Point Mutations with Real-Time PCR in Stool Specimens from Children Infected with Helicobacter pylori

Reports have indicated an increasing prevalence of clarithromycin resistance in children relative to adults. Thus, it is important to investigate primary clarithromycin resistance before therapy to avoid treatment failure. A2142G, A2143G, and A2142C point mutations in the peptidyltransferase region of the 23S ribosomal RNA (rRNA) of Helicobacter pylori (H. pylori) strains isolated from children with gastrointestinal symptoms and asymptomatic children were evaluated via real-time polymerase chain reaction (RT-PCR) using fecal DNA samples. The presence of H. pylori was determined using a fecal H. pylori antigen enzyme-linked immunosorbent assay (ELISA) kit from the stools of children (n = 543). A2143G, A2142C, and A2142G point mutations were detected via RT-PCR and confirmed by sequencing the 23S rDNA. Fecal H. pylori antigen testing was positive in 101 symptomatic (49) and asymptomatic (52) children. A significant difference was found between the 0–5- and 5–18-year-old groups in terms of the A2143G and A2142G point mutations (p = 0.001). The A2142C mutation was not detected. There was a significant difference in the A2143G mutation between the symptomatic and asymptomatic 5–18-year-old children (p = 0.019). Macrolides are frequently used to treat upper respiratory tract infections in children due to their selective pressure effect. We suggest that H. pylori strains carrying mutations in the 23S RNA subunit conferring clarithromycin resistance may lead to an intense inflammatory response in the gastric epithelial cells, allowing them to proliferate more rapidly and causing possible diarrhea, halitosis, or abdominal pain in children.

Helicobacter pylori-Clarithromycin Resistance in Symptomatic Pediatric Patients in a High Prevalence Country

INTRODUCTION

Failure to eradicate Helicobacter pylori despite antibiotic treatment is generally attributed to increasing clarithromycin resistance conferred by point mutations in the 23S-rRNA gene or metronidazole resistance attributed to rdxA gene (HP0954) deletion in patients. Scarce data for pediatric population are available from developing countries.

OBJECTIVES

The aim of the present study was to determine the presence of A2142G/C and A2143G mutations in the 23S-rRNA gene and/or rdxA gene (HP0954) deletion in a group of symptomatic H pylori-infected children recruited from an area with high infection rate and risk of gastric cancer.

PATIENTS AND METHODS

We recruited 118 patients referred for upper endoscopy for gastrointestinal symptoms. The presence of H pylori was determined by urease test and histological staining. The rdxA gene (HP0954) deletion, and 2142G/C and A2143G mutations were determined by polymerase chain reaction-restriction fragment length polymorphism. A subgroup of infected patients received a 14-day regimen of omeprazole, amoxicillin, and clarithromycin. The effectiveness of this regime was determined by stool antigen determination 8 weeks after treatment.

RESULTS

About 21% of the analyzed infected patients showed mutation in the 23S-rRNA gene, with the A2143G transition as the more frequent mutation, and 2% of the patients showed rdxA gene (HP0954) deletion. After treatment, 25% of the patients continued to harbor the bacteria; of these, 67% carried the A2143G mutation.

CONCLUSIONS

H pylori-infected pediatric patients from Chile show high prevalence of the mutation responsible for clarithromycin resistance. The failure to eradicate H pylori can be attributed to the presence of the A2143G mutation.

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.

Sequential Therapy is Superior to Triple Therapy for Helicobacter pylori Infection in Children: A Meta-Analysis

OBJECTIVES

To assess the efficacy and safety of 10-d sequential therapy compared to 5 to 14-d triple therapy for treating Helicobacter pylori infections in children according to the eradication rates.

METHODS

The Cochrane Library, MEDLINE, EMBASE, China National Knowledge Infrastructure databases, and other sources were searched in November 2014 without language restrictions. Randomized controlled trials (RCTs) that compared sequential therapy with triple therapy for H. pylori eradication in children were included. Dichotomous data were pooled to obtain the relative risk (RR) of the eradication rate with a 95% confidence interval (CI).

RESULTS

Fourteen RCTs with 1698 participants (718 and 980 for sequential and triple therapy, respectively) were included. The intention-to-treat eradication rates were 73% (95% CI: 70-76) and 66% (95% CI: 64-70) for sequential and triple therapy, respectively. The pooled RR was 1.16 (95% CI: 1.09-1.23), resulting in a number needed to treat of 16 (95% CI: 10-48), favoring sequential therapy. Sequential therapy was superior to 7- and 10-d triple therapy. Sequential and triple therapy did not differ significantly in the overall risk of adverse effects.

CONCLUSIONS

In children, sequential therapy appears to be superior to triple therapy for H. pylori eradication, although the eradication rates remain lower than the expected goal with both treatments. Factors-associated with a higher risk of eradication failure, such as compliance and antimicrobial resistance, remain insufficiently investigated. Therefore, further high-quality RCTs are needed to compare these different eradication treatment approaches.

Helicobacter pylori colonization of the oral cavity: A milestone discovery

Over the past several years, the severity of Helicobacter pylori (H. pylori) infections has not significantly diminished. After successful eradication, the annual H. pylori recurrence rate is approximately 13% due to oral H. pylori infection. Established clinical diagnostic techniques do not identify an oral etiologic basis of H. pylori prior to gastric infection. There has been disagreement as to whether oral infection of H. pylori exists or not, with no definite conclusion. In medical practice, negative results with the urea breath test suggest that the stomach infection of H. pylori is cured in these patients. In fact, patients can present negative urea breath test results and yet exhibit H. pylori infection due to oral infection. The present paper provides evidence that H. pylori oral infection is nonetheless present, and the oral cavity represents a secondary site for H. pylori colonization.

Helicobacter pylori Eradication in Patients with Immune Thrombocytopenic Purpura: A Review and the Role of Biogeography

Idiopathic thrombocytopenic purpura (ITP) is typically a diagnosis of exclusion, assigned by clinicians after ruling out other identifiable etiologies. Since a report by Gasbarrini et al. in 1998, an accumulating body of evidence has proposed a pathophysiological link between ITP and chronic Helicobacter pylori (H. pylori) infection. Clinical reports have described a spontaneous resolution of ITP symptoms in about 50% of chronic ITP patients following empirical treatment of H. pylori infection, but response appears to be geography dependent. Studies have also documented that ITP patients in East Asian countries are more likely to express positive antibody titers against H. pylori-specific cytotoxic-associated gene A (CagA), a virulence factor that is associated with an increased risk for gastric diseases including carcinoma. While a definitive mechanism by which H. pylori may induce thrombocytopenia remains elusive, proposed pathways include molecular mimicry of CagA by host autoantibodies against platelet surface glycoproteins, as well as perturbations in the phagocytic activity of monocytes. Traditional treatments of ITP have been largely empirical, involving the use of immunosuppressive agents and immunoglobulin therapy. However, based on the findings of clinical reports emerging over the past 20 years, health organizations around the world increasingly suggest the detection and eradication of H. pylori as a treatment for ITP. Elucidating the exact molecular mechanisms of platelet activation in H. pylori-positive ITP patients, while considering biogeographical differences in response rates, could offer insight into how best to use clinical H. pylori eradication to treat ITP, but will require well-designed studies to confirm the suggested causative relationship between bacterial infection and an autoimmune disease state.