OBJECTIVEThis article aimed to review the incidence of Helicobacter pylori (H. pylori) infection and its therapy.

DATA SOURCESRelevant articles published in English were identified by searching in PubMed from 2000 to 2013, with keywords "H. pylori". Important references from selected articles were also retrieved from Elsevier, Wiley, EBSCO, and SPRINGER. The Chinese articles published were searched from China National Knowledge Infrastructure (CNKI).

STUDY SELECTIONArticles about "prevalence", "gastric carcinoma", "peptic ulcer", "gastroesophageal reflux disease", "functional dyspepsia", "pathogenic mechanism", "therapy", "eradication rate", "antibiotic resistance", and "gene polymorphisms" were selected.

RESULTSThe decreased infection rates of H. pylori could also be linked to the changed disease spectrum, such as the decreased morbidity and recurrence rate of H. pylori-related peptic ulcer, and the increased morbidity of gastroesophageal reflux. Although different treatment regimens have been used for H. pylori infection, the H. pylori eradication rate declined gradually. Due to primary resistance to antibiotics, the gene polymorphism of host and infected strain, and the therapy regimes, H. pylori eradication became even more difficult.

CONCLUSIONSThe prevalence of H. pylori infection had been decreasing, but the rate of eradication failure has dramatically risen in many countries due to resistance to antibiotic. H. pylori therapy in clinical practice is becoming progressively more difficult.

Drug Resistance, Bacterial ; genetics ; Helicobacter Infections ; drug therapy ; epidemiology ; Helicobacter pylori ; drug effects ; genetics ; pathogenicity ; Humans

No abstract available.
Adenoma ; Gastric Mucosa ; Helicobacter Infections ; Helicobacter pylori/*drug effects ; Humans ; *Time

BACKGROUND/AIMS: We can expect to reduce costs and decrease adverse events by using low-dose triple therapy for H. pylori eradication. However, the efficacy of low-dose triple therapy for Koreans is questionable. In this study, we compared the efficacy of low-dose triple therapy with standard-dose triple therapy. METHODS: We enrolled 480 patients who were diagnosed as suffering with H. pylori infection via endoscopy with biopsy or CLO testing. Thirty patients were excluded due to malignancy or having undergone previous antibiotics medication. Two hundred and eighty patients received standard-dose triple therapy (pantoprazole 40 mg b.d, amoxicillin 1,000 mg b.d., and clarithromycin 500 mg b.d.), and 170 patients received low-dose triple therapy (pantoprazole 40 mg b.d., amoxicillin 750 mg b.d., and clarithromycin 250 mg b.d.). Eradication was evaluated 4~6 weeks after administering the medication. RESULTS: The H. pylori eradication rate was 77.9% in the standard-dose group, and 74.7% in the low-dose group. There was no significant difference in the H. pylori eradication rate between the two groups (p=0.444). The adverse events were significantly more frequent in the standard-dose group. One patient each in both groups discontinued medication because of an adverse event. CONCLUSIONS: The efficacy of low-dose therapy is similar to standard-dose therapy, and the adverse events are less frequent with low-dose therapy. This suggests that low-dose therapy would be preferred when considering the cost- benefit and low rate of adverse drug events.
Amoxicillin ; Anti-Bacterial Agents ; Biopsy ; Clarithromycin ; Drug-Related Side Effects and Adverse Reactions ; Endoscopy ; Helicobacter pylori* ; Helicobacter* ; Humans

No abstract availble.
Anti-Bacterial Agents/*therapeutic use ; Drug Resistance, Bacterial ; Helicobacter Infections/*drug therapy/microbiology ; *Helicobacter pylori/drug effects ; Humans ; Proton Pumps/adverse effects

The distribution of minimal inhibitory concentrations (MIC) for amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, and fluoroquinolone (ciprofloxacin, levofloxacin, and moxifloxacin) have shifted to higher concentrations from 1987 to 2003 in Helicobacter pylori (H. pylori) strains isolated from Korean patients. MIC values of secondary isolates were higher than those of primary isolates. Of treatment-failure patients, 16.4% showed mixed infections with both antibiotic-susceptible and -resistant H. pylori strains. A total of 89.6% of patients with treatment failure and 52.3% of patients without antibiotic treatment had H. pylori strains resistant to two or more antimicrobial agents (multi-drug resistance, MDR). The most common antibiotics showing MDR were clarithromycin, metronidazole, and azithromycin. The resistance rates to both amoxicillin and clarithromycin were 34.3% in secondary isolates and 6.2% in primary isolates. The resistance rates to both clarithromycin and metronidazole were 73.1% in secondary isolates and 7.7% in primary isolates. In addition, there was a significant difference in antibiotic resistance between two institutions located at Seoul and Gyeonggi provinces. To provide adequate informations about susceptible antibiotics to clinicians, continuous surveillance of antibiotic susceptibilities is needed in Korea.
*Drug Resistance, Bacterial ; Drug Resistance, Multiple, Bacterial ; Helicobacter pylori/*drug effects/isolation & purification ; Humans ; Korea ; Microbial Sensitivity Tests

OBJECTIVETo investigate the relationship between the helicobacter pylori (HP) infection and the genetic instability of mitochondrial DNA (mtDNA) in human gastric adenocarcinoma epithelial cells (AGS).

METHODSAfter treated with extracts of HP11638 (CagA+, VacA+) or Hp11638 mutant strain (CagA+, VacA-), AGS cells were collected, and mitochondrial DNA was extracted and Cox-I, Cox-II, Cox-III, ATPase6, ATPase8 and Cytb genes and the D-Loop region were amplified by PCR and then sequenced.

RESULTSThe mutation rates of the mtDNA in AGS cells were correlated with the extracts of the two HP strains in a concentration- and time-dependent manner. But the mtDNA mutation rate in AGS cells treated with the HP11638 extract was higher than that treated with the Hp11638 mutant extract. Total of 616 mutations in D-Loop region were detected, including 489 point mutations, 81 insertions and 46 deletions. Among them, 70.9% (437/616) belonged to GC to AT and AT to GC transition. Seventeen out of 20 (85%) AGS cells treated with extract of HP had mutations in 303PolyC, 16184PolyC and 514CA regions of mtDNA D-Loop. No mutation was detected in Cox-I, Cox-II, Cox-III, ATPase6 and ATPase8 genes, three point mutations were found in the Cytb gene.

CONCLUSIONHP can cause the accumulation of mutations in mtDNA, in particular, in the D-Loop region, and the VacA participated in the process.

Antigens, Bacterial ; pharmacology ; Base Sequence ; DNA, Mitochondrial ; drug effects ; genetics ; Endothelial Cells ; drug effects ; pathology ; Helicobacter Infections ; complications ; Helicobacter pylori ; chemistry ; Humans ; Mutation ; Stomach ; pathology

No abstract available.
Anti-Infective Agents/*therapeutic use ; Drug Resistance, Bacterial ; Helicobacter Infections/*drug therapy/microbiology ; Helicobacter pylori/*drug effects ; Humans ; Metronidazole/*therapeutic use

BACKGROUND/AIMS: Development of antibiotic resistance is a significant clinical problem in the eradication of H. pylori. To select an appropriate regimen, systematic information on antibiotic resistance is mandatory. Thus, we investigated the distribution of minimal inhibitory concentration (MIC) and evaluated the antibiotic resistance of H. pylori isolates from Korean patients in 2003. METHODS: The susceptibility of 65 isolates obtained in 2003 to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, and ciprofloxacin were determined by agar dilution method. RESULTS: Resistance rates of H. pylori to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, and ciprofloxacin were 18.5%, 13.8%, 66.2%, 12.3%, 32.3%, and 33.8%, respectively. Multi-drug resistance rate of H. pylori was 47.7%. Especially, 6.2% of the H. pylori isolates were resistant to both amoxicillin and clarithromycin. In addition, resistance to amoxicillin and clarithromycin resulted in decreasing tendency of the eradication efficacy for H. pylori. CONCLUSIONS: These results indicate that the antibiotics used for H. pylori eradication show high resistance rates in Korea. Furthermore, continuous surveillance of antibiotic susceptibilities should be needed and further increases in antibiotic resistance would require susceptibility testing before treatment to maximize the efficacy of H. pylori treatment.
Aged ; *Drug Resistance, Bacterial ; Drug Resistance, Multiple, Bacterial ; English Abstract ; Female ; Helicobacter Infections/microbiology ; Helicobacter pylori/*drug effects ; Humans ; Korea ; Male ; Middle Aged

OBJECTIVETo demonstrate the correlation of rdxA gene mutation and metronidazole (MTZ) resistance of H.pylori isolates in the local area.

METHODSClinical strains of H.pylori were isolated from gastric biopsy of patients. Resistance to metronidazole of the isolates was determined by using diffusion test and two fold dilution test. Genome DNAs of the isolates were prepared for PCR to detect rdxA gene. The target amplification products were sequenced after T-A cloning. The sequences were compared with the reported sequences from Hp26695 and 134 other strains of H.pylori.

RESULTSMTZ resistance rate was 76.1% in 21 clinical isolates. The target fragment 886 bp in length containing rdxA gene could be successfully amplified. In comparison with the reported corresponding sequence of H.pylori stain 26695, homologies of the nucleotide sequences from the amplification products were 90.1% approximate, equals 95.1%. Mutations caused by base insertion/deletion and substitution in the MTZ resistance isolates were found. Among these mutations, two types of insertion mutations have not been reported in literatures. No same mutations were present in the MTZ sensitive isolates.

CONCLUSIONThe rdxA gene mutation may play an important role in MTZ resistance of H.pylori.

Amino Acid Sequence ; Drug Resistance, Bacterial ; Helicobacter pylori ; drug effects ; genetics ; Metronidazole ; pharmacology ; Molecular Sequence Data ; Mutation ; Nitroreductases ; chemistry ; genetics

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; China ; Drug Resistance, Bacterial ; Female ; Helicobacter Infections ; microbiology ; Helicobacter pylori ; classification ; drug effects ; isolation & purification ; Humans ; Male ; Middle Aged ; Young Adult