Primary and Acquired Helicobacter pylori Resistance to Clarithromycin, Metronidazole, and Amoxicillin--Influence on Treatment Outcome

Adamek, R. J.

doi:10.1016/s0002-9270(97)00110-x

Cited by 80 publications

(110 citation statements)

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“…These ratios of resistance are higher than those published by most authors. Metronidazole resistance has been reported in up to 50% of isolates,3 7 9-11clarithromycin resistance in 1–15%,3 5-7 9-11 13amoxycillin resistance in 0.3–6%,10 11 13 but resistance to tetracycline has not generally been reported 10. However, our results are comparable with those recently reported in adults with gastric ulcers 22…”

Section: Discussionmentioning

confidence: 99%

Antibiotic resistance and antibiotic sensitivity based treatment in Helicobacter pylori infection: advantages and outcome

Street

2001

Archives of Disease in Childhood

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Aims-To compare two strategies for the eradication of Helicobacter pylori infection. Methods-Groups 1 and 2 each consisted of 75 consecutive patients. Patients in group 1 were treated with two antibiotics based on antibiotic susceptibility testing; those in group 2 received amoxycillin and clarithromycin for eight days, together with either ranitidine or omeprazole. Eradication rate was assessed in both groups six months after treatment. Results-In group 1, H pylori grew in culture in 63/75 cases. Susceptibility testing showed that 35/63 isolates were resistant to metronidazole, 10/63 to clarithromycin, 2/63 to ampicillin, 1/63 to tetracycline, and 5/63 to both clarithromycin and metronidazole. In group 1 the infection was eradicated in 96% of the initial 75 subjects, and in 98% of the subjects treated according to the antibiotic assay (62/63). As two patients were lost at follow up the overall eradication rate was 99%. In group 2, eradication was achieved in 61/75 subjects (81%). This was significantly lower than the percentage of eradication observed in group 1 (81% versus 99%). Conclusions-Antibiotic susceptibility tests are useful in childhood as a very high percentage of subjects are cured. This approach is costly, but selective antibiotic treatment contributes to limit further development of antibiotic resistance, and money is saved in terms of reinvestigation and further repeated treatments.

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Section: Discussionmentioning

confidence: 99%

Antibiotic resistance and antibiotic sensitivity based treatment in Helicobacter pylori infection: advantages and outcome

Street

2001

Archives of Disease in Childhood

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“…Emerging resistance of H. pylori strains to several classes of commonly used, widely available antibiotics is the major factor contributing toward the failure of eradication therapy. Wide variations in antibiotic resistance patterns have been described according to differing geographic regions [2,3]. Antibiotic resistance has been attributed to key mutations in a relatively small number of nucleotide and amino acid sequences.…”

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confidence: 99%

Analysis of Clinical Isolates of Helicobacter pylori in Pakistan Reveals High Degrees of Pathogenicity and High Frequencies of Antibiotic Resistance

et al. 2014

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Background Antibiotic resistance in Helicobacter pylori contributes to failure in eradicating the infection and is most often due to point and missense mutations in a few key genes. Methods The antibiotic susceptibility profiles of H. pylori isolates from 46 Pakistani patients were determined by Etest. Resistance and pathogenicity genes were amplified, and sequences were analyzed to determine the presence of mutations. Results A high percentage of isolates (73.9%) were resistant to metronidazole (MTZ), with considerable resistance to clarithromycin (CLR; 47.8%) and amoxicillin (AML; 54.3%) also observed. Relatively few isolates were resistant to tetracycline (TET; 4.3%) or to ciprofloxacin (CIP; 13%). However, most isolates (n = 43) exhibited resistance to one or more antibiotics. MTZ-resistant isolates contained missense mutations in oxygen-independent NADPH nitroreductase (RdxA; 8 mutations found) and NADH flavin oxidoreductase (FrxA; 4 mutations found). In the 23S rRNA gene, responsible for CLR resistance, a new point mutation (A2181G) and 4 previously reported mutations were identified. Pathogenicity genes cagA, dupA, and vacA s1a/m1 were detected frequently in isolates which were also found to be resistant to MTZ, CLR, and AML. A high percentage of CagA and VacA seropositivity was also observed in these patients. Phylogenetic analysis of partial sequences showed uniform distribution of the 3′ region of cagA throughout the tree. Conclusions We have identified H. pylori isolates in Pakistan which harbor pathogenicity genes and worrying antibiotic resistance profiles as a result of having acquired multiple point and missense mutations. H. pylori eradication regimens should therefore be reevaluated in this setting.

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Section: Discussionmentioning

confidence: 99%

“…The strong antisecretory activity of PPIs has been thought to play an important role in the eradication of H. pylori , as PPI-induced high gastric pH has been reported to increase the sensitivity of H. pylori to antimicrobial agents [24,28–32]. Therefore, pretreatment with PPI or H2RA has been advocated based on the assumption that elevation of the gastric pH prior to the start of antibiotic administration would increase the cure rate [31,32]. While this issue concerning pretreatment with PPIs has remained controversial, a meta-analysis investigating the influence of PPI pretreatment on the efficacy of triple and quadruple H. pylori eradication therapies did not reveal any difference in the eradication rates between patients with and without PPI pretreatment [25].…”

Section: Discussionmentioning

confidence: 99%

Influence of pretreatment with H2 receptor antagonists on the cure rates of Helicobacter pylori eradication

et al. 2011

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SummaryBackgroundPretreatment with a proton pump inhibitor (PPI) reportedly decreases the efficacy of Helicobacter pylori (H. pylori) eradication, however, the effect of pretreatment with an H2 receptor antagonist (H2RA) on H. pylori eradication has not yet been studied. We compared the efficacy of eradication regimen (lansoprazole/amoxicillin/clarithromycin) in patients with H. pylori infection with or without H2RA pretreatment.Material/MethodsIn this retrospective study conducted at three centers, 310 patients with H. pylori infection were treated. The diagnosis of H. pylori infection was made using the rapid urease test, bacterial cultures and histological examination of endoscopic biopsy specimens. The patients were assigned to receive an eradication regimen first or following pretreatment with H2RA. Eradication was assessed using the 13C-urea breath test more than 4 weeks after the completion of therapy.ResultsOverall, H. pylori was eradicated in 79.7% of the cases: the eradication rate was 81.6% in the pretreatment group, and 77.6% in the eradication first group (p=0.3799, chi-square test). No significant difference in the eradication rate was observed between the two groups.ConclusionsPretreatment with H2RA had no significant influence on the efficacy of H. pylori eradication therapy.

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Primary and Acquired Helicobacter pylori Resistance to Clarithromycin, Metronidazole, and Amoxicillin--Influence on Treatment Outcome

Cited by 80 publications

References 0 publications

Antibiotic resistance and antibiotic sensitivity based treatment in Helicobacter pylori infection: advantages and outcome

Antibiotic resistance and antibiotic sensitivity based treatment in Helicobacter pylori infection: advantages and outcome

Analysis of Clinical Isolates of Helicobacter pylori in Pakistan Reveals High Degrees of Pathogenicity and High Frequencies of Antibiotic Resistance

Influence of pretreatment with H2 receptor antagonists on the cure rates of Helicobacter pylori eradication

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