The standard therapy for Helicobacter pylori infection in Korea is a triple-drug regimen consisting of a proton pump inhibitor with two antibiotics such as clarithromycin, amoxicillin, and metronidazole. However, as the eradication rate of this regimen has declined over the past decade, this prompted the formulation of new therapeutic regimens. New therapeutic strategies against H. pylori infection that had been tried all over the world include sequential therapy, concomitant therapy, and tailored therapy This article will review the basic concepts and the results of previous clinical trials on the aforementioned new therapeutic regiments.
Amoxicillin/pharmacology/therapeutic use ; Anti-Bacterial Agents/pharmacology/*therapeutic use ; Clarithromycin/pharmacology/therapeutic use ; Disease Eradication/trends ; Drug Therapy, Combination ; Helicobacter Infections/*drug therapy ; *Helicobacter pylori/drug effects ; Humans ; Nitroimidazoles/pharmacology/therapeutic use ; Proton Pump Inhibitors/pharmacology/therapeutic use

Although, the prevalence of Helicobacter pylori infection in Korea has declined owing to the eradication therapy, recent seroprevalence of H. pylori infection is still reported to be as high as 54.4%. Until now, "standard regimen" for eradication of H. pylori has been conventional triple therapy consisting of proton pump inhibitor, amoxicillin, and clarithromycin. However, with the increase in antibiotic resistance, especially against clarithromycin, the eradication rate of conventional triple therapy has steadily declined during the past 13 years in Korea. Present eradication rate of standard triple therapy is reported to be less than 80%, which is the Maginot line of efficacy for the currently available regimen. Therefore, new first line eradication regimen is needed to enhance the eradication rate of H. pylori infection.
Amoxicillin/pharmacology/therapeutic use ; Anti-Bacterial Agents/pharmacology/*therapeutic use ; Asian Continental Ancestry Group ; Clarithromycin/pharmacology/therapeutic use ; Disease Eradication/trends ; Drug Administration Schedule ; Drug Therapy, Combination ; Helicobacter Infections/*drug therapy ; *Helicobacter pylori/drug effects ; Humans ; Proton Pump Inhibitors/therapeutic use ; Republic of Korea

OBJECTIVEMany clinical studies indicated that Helicobacter pylori (Hp) strains rarely acquired resistance to amoxicillin but easily to clarithromycin and metronidazole. However, it was unclear whether the antibiotic resistance of Hp strains was induced or passively selected during long-term or frequent treatment with metronidazole, clarithromycin and amoxicillin. To compare the propensity of acquired resistance to antibiotics, Hp strains were exposed to amoxicillin, clarithromycin and metronidazole in vitro in this study.

METHODSAll Hp strains were clinical isolates, derived from biopsy specimens of patients taken during endoscopy in the Affiliated Children's Hospital, Zhejiang University School of Medicine from December 2004 to July 2005. To seek susceptible strains, the minimum inhibitory concentrations (MICs) of the three antibiotics were determined by using Epsilometer test (E-test) method. In vitro induction was carried out on serially doubling concentrations of antibiotics incorporated into agar. Isolates were also transferred at least three times on antimicrobial agent-free medium, followed by a redetermination of the final MICs to assess the stability of the selected resistance.

RESULTS7 strains were exposed to antibiotics in vitro. After 6 - 17 passages on antibiotic plates, 7 and 3 strains respectively acquired resistance to metronidazole and clarithromycin, while none of the strains were resistant to amoxicillin. The inductive folds were different among three groups: 8 - 128 folds in metronidazole group; 1 - 256 folds in clarithromycin group; 2 - 16 folds in amoxicillin group. After three transfers on antimicrobial agent-free medium, the MICs decreased significantly in amoxicillin group (P < 0.05) but had no change in metronidazole group and clarithromycin group (P > 0.05).

CONCLUSIONSThe metronidazole resistance in Hp was easily selected. Strains resistant to clarithromycin could be selected, but the amoxicillin resistance could not be selected after in vitro induction for Hp isolated from children. The correlation between in vitro and in vivo outcomes suggests that acquired resistance was the main cause for the resistance in Hp strains. The laboratory results of in vitro antibiotic induction could help predict the actual rate of resistance and select appropriate antibiotics for treatment.

Amoxicillin ; pharmacology ; Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Anti-Infective Agents ; pharmacology ; therapeutic use ; Biopsy ; Child ; Clarithromycin ; pharmacology ; Drug Resistance, Microbial ; drug effects ; Drug Resistance, Multiple, Bacterial ; drug effects ; Helicobacter Infections ; drug therapy ; microbiology ; Helicobacter pylori ; drug effects ; isolation & purification ; Humans ; Metronidazole ; pharmacology ; Microbial Sensitivity Tests ; methods ; Tetracycline ; pharmacology

The prevalence of Helicobacter pylori infection in Korea shows a decreasing trend and has changed to that of developed country, especially for those below 30 years old. However, the primary antibiotic resistance rates are higher than those of developed countries. The reason for the decrease in the efficacy of standard triple therapy is mainly due to the increase in the resistance against clarithromycin. Sequential therapy seems to be more effective than the standard triple therapy, but the intention-to-treat eradication rate of sequential therapy in Korea, which is mostly under 80.0%, is still not satisfactory. Therefore, a promising regimen is needed. Recently, the Japanese health insurance system admitted 'H. pylori-infected gastritis' as an indication of eradication. Furthermore, the Kyoto Consensus Meeting on H. pylori Gastritis held from January 30th to February 1st, 2014, proposed that 'all H. pylori positive patients should be offered to receive H. pylori eradication'. This suggests that the concept of eradication has been changed from 'treatment' to 'prevention'. Various individualized tailored therapy based on the polymorphism, age and other demographic factors and antibiotic resistance has been attempted to maximize H. pylori eradication therapy. The aim of this article is to review the current epidemiology, H. pylori resistance state, treatment guideline, and to assess the possible future strategy and treatment for H. pylori infection in Korea.
Anti-Bacterial Agents/pharmacology/*therapeutic use ; Aryl Hydrocarbon Hydroxylases/genetics/metabolism ; Clarithromycin/pharmacology/therapeutic use ; Disease Eradication/trends ; Drug Resistance, Bacterial ; Drug Therapy, Combination ; Guidelines as Topic ; Helicobacter Infections/*drug therapy/epidemiology ; *Helicobacter pylori/drug effects ; Humans ; Quinolones/pharmacology/therapeutic use ; Republic of Korea ; Treatment Failure

OBJECTIVE: To examine the infection and bacteria resistance of Helicobacter pylori (H.pylori) to clarithromycin and furazolidone,to determine whether the antibiotic resistance is primary or secondary, and to decide if a new H.pylori infection plays a role in eradication failures. METHODS: Twenty one H.pylori had been isolated from human biopsy specimens, and antimicrobial susceptibility testing was performed. DNA fingerprints were generated using random amplification polymorphic DNA (RAPD) to determine the identity of H.pylori before and after the eradication therapy. RESULTS: Eight bacteria resisted against clarithromycin, and one against furazolidone, with the resistant rates 38.1% and 4.8% respectively. The number of primary antibiotic resistance, secondary resistance and new infection was 1 for each. CONCLUSION Resistance to clarithromycin is more common compared with that to furazolidone. Development of primary and secondary resistance to clarithromycin occurs as a rule in eradication failures. New H.pylori infection plays a role in eradication failures.
Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Clarithromycin ; pharmacology ; therapeutic use ; DNA Fingerprinting ; DNA, Bacterial ; analysis ; genetics ; isolation & purification ; Drug Resistance, Bacterial ; Furazolidone ; pharmacology ; therapeutic use ; Helicobacter Infections ; drug therapy ; microbiology ; Helicobacter pylori ; drug effects ; genetics ; Humans ; Microbial Sensitivity Tests ; Random Amplified Polymorphic DNA Technique

BACKGROUND/AIMS: This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea. METHODS: H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method. RESULTS: There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference. CONCLUSIONS: There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations.
Amoxicillin/pharmacology ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Aza Compounds/pharmacology ; Azithromycin/pharmacology ; Ciprofloxacin/pharmacology ; Clarithromycin/pharmacology ; *Drug Resistance, Bacterial ; Female ; Helicobacter Infections/*epidemiology/microbiology ; Helicobacter pylori/*drug effects/isolation & purification ; Humans ; Male ; Metronidazole/pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Ofloxacin/pharmacology ; Quinolines/pharmacology ; Republic of Korea/epidemiology ; Tetracycline/pharmacology

BACKGROUND/AIMS: This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea. METHODS: H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method. RESULTS: There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference. CONCLUSIONS: There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations.
Amoxicillin/pharmacology ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Aza Compounds/pharmacology ; Azithromycin/pharmacology ; Ciprofloxacin/pharmacology ; Clarithromycin/pharmacology ; *Drug Resistance, Bacterial ; Female ; Helicobacter Infections/*epidemiology/microbiology ; Helicobacter pylori/*drug effects/isolation & purification ; Humans ; Male ; Metronidazole/pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Ofloxacin/pharmacology ; Quinolines/pharmacology ; Republic of Korea/epidemiology ; Tetracycline/pharmacology

We evaluated the antibiotic resistance rates and eradication rates of clarithromycin based triple therapy from 2005 to 2010 retrospectively. In addition, we investigated the mechanism of clarithromycin resistance in Helicobacter pylori strains isolated from Korean patients. Two hundred and twelve strains of H. pylori were isolated from 204 patients. H. pylori ATCC 43504 was used as the standard strain. The eradication rates of H. pylori from 2005 to 2010 were 89.3%, 82.6%, 86.3%, 87.7%, 81.8%, and 84.2%, respectively. Total eradication rate was 84.9%. DNA sequences of the 23S RNA gene in clarithromycin-resistant strains were determined. The resistance rates of H. pylori to amoxicillin, clarithromycin, metronidazole, tetracycline, ciprofloxacin, moxifloxacin, and levofloxacin were 9.0%, 8.5%, 36.3%, 0%, 14.2%, 14.2%, and 14.2%, respectively. The multidrug resistance rate of H. pylori was 16.5%. Sequence analysis of clarithromycin-resistant strains showed an A2144G mutation in 8 of 14 strains (57.1%), a T2183C mutation in 5 of 14 strains (35.7%), and double mutations of both A2144G and T2183C in 1 of 14 strains (7.1%). In the present study, triple therapy may still be an effective eradication therapy for H. pylori infections in Korea. The A2144G and T2183C mutations are mainly present in clarithromycin-resistant isolates.
Adult ; Aged ; Anti-Bacterial Agents/pharmacology/*therapeutic use ; Asian Continental Ancestry Group ; Clarithromycin/*therapeutic use ; DNA, Bacterial/analysis ; Drug Resistance, Bacterial/genetics ; Female ; Helicobacter Infections/*drug therapy/microbiology ; Helicobacter pylori/drug effects/genetics/*isolation & purification ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Mutation ; Polymerase Chain Reaction ; RNA, Ribosomal, 23S/genetics ; Republic of Korea ; Retrospective Studies ; Sequence Analysis, DNA