scholarly journals Antibiotic Resistance Mechanisms ofHelicobacter pylori

1999 ◽  
Vol 13 (3) ◽  
pp. 243-249 ◽  
Author(s):  
Paul S Hoffman

Infection withHelicobacter pyloriis most frequently associated with gastritis and peptic ulcer disease. Antimicrobial intervention, together with proton pump inhibitors, has become the standard therapy for treating this disease. Resistance to clarithromycin and metronidazole, two of the most commonly used antimicrobials for treatment ofH pyloriinfections, is often associated with treatment failures and relapse of infection. Clarithromycin resistance arises through mutations leading to base changes in 23S ribosomal RNA subunits, while resistance to metronidazole is due to mutations in therdxAgene, which encodes a novel nitroreductase that is responsible for reductive activation of the drug. Products of metronidazole activation are mutagenic and can be demonstrated to increase both the mutation frequency and the frequency at which antibiotic resistance arises inH pylori.

2019 ◽  
Vol 9 (1) ◽  
pp. 54 ◽  
Author(s):  
Seung In Seo ◽  
Byoung Joo Do ◽  
Jin Gu Kang ◽  
Hyoung Su Kim ◽  
Myoung Kuk Jang ◽  
...  

Background/Aims: Clarithromycin resistance in Helicobacter pylori is associated with point mutations in the 23S ribosomal RNA (rRNA) gene. We investigated the point mutations in the 23S rRNA genes of patients with clarithromycin-resistant H. pylori and compared the H. pylori eradication rates based on the point mutations. Methods: A total of 431 adult patients with H. pylori infection were recruited in Kangdong Sacred Heart Hospital in 2017 and 2018. Patients who did not have point mutations related to clarithromycin resistance and/or had clinically insignificant point mutations were treated with PAC (proton pump inhibitor, amoxicillin, clarithromycin) for seven days, while patients with clinically significant point mutations were treated with PAM (proton pump inhibitor, amoxicillin, metronidazole) for seven days. H. pylori eradication rates were compared. Results: Sequencing-based detection of point mutations identified four mutations that were considered clinically significant (A2142G, A2142C, A2143G, A2143C). The clarithromycin resistance rate was 21.3% in the overall group of patients. A2143G was the most clinically significant point mutation (84/431, 19.5%), while T2182C was the most clinically insignificant point mutation (283/431, 65.7%). The overall H. pylori eradication rate was 83.7%, and the seven-day PAM-treated clarithromycin-resistance group showed a significantly lower eradication rate than the seven-day PAC-treated nonresistance group (ITT; 55.4% (51/92) vs. 74.3% (252/339), p = 0.001, PP; 66.2% (51/77) vs. 88.4% (252/285), p = 0.0001). Conclusions: There were significantly lower eradication rates in the patients with clarithromycin-resistant H. pylori when treated with PAM for seven days. A future study comparing treatment regimens in clarithromycin-resistant H. pylori-infected patients may be necessary.


2015 ◽  
Vol 26 (3) ◽  
pp. 137-144 ◽  
Author(s):  
Nelson F Eng ◽  
Gustavo Ybazeta ◽  
Katrina Chapman ◽  
Nya L Fraleigh ◽  
Rebecca Letto ◽  
...  

BACKGROUND:Helicobacter pyloriplays a significant role in gastritis and ulcers. It is a carcinogen as defined by the WHO, and infection can result in adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. In Canada, rates of antimicrobial resistance are relatively unknown, with very few studies conducted in the past 15 years.OBJECTIVE: To examine rates of resistance in Sudbury, Ontario, compare antimicrobial susceptibility methods and attempt to determine the molecular basis of antibiotic resistance.METHODS: Patients attending scheduled visits at Health Sciences North (Sudbury, Ontario) provided gastric biopsy samples on a volunteer basis. In total, 20H pyloriisolates were collected, and antimicrobial susceptibility testing (on amoxicillin, tetracycline, metronidazole, ciprofloxacin, levofloxacin and clarithromycin) was conducted using disk diffusion and E-test methods. Subsequently, genomic DNA from these isolates was sequenced to detect mutations associated with antimicrobial resistance.RESULTS: Sixty-five percent of the isolates were found to be resistant to at least one of the listed antibiotics according to E-test. Three isolates were found to be resistant to ≥3 of the above-mentioned antibiotics. Notably, 25% of the isolates were found to be resistant to both metronidazole and clarithromycin, two antibiotics that are normally prescribed as part of first-line regimens in the treatment ofH pyloriinfections in Canada and most of the world. Among the resistant strains, the sequences of 23S ribosomal RNA andgyrA, which are linked to clarithromycin and ciprofloxacin/levofloxacin resistance, respectively, revealed the presence of known point mutations associated with antimicrobial resistance.CONCLUSIONS: In general, resistance to metronidazole, ciprofloxacin/levofloxacin and clarithromycin has increased since the studies in the early 2000s. These results suggest that surveillance programs ofH pyloriantibiotic resistance may need to be revisited or improved to prevent antimicrobial therapy failure.


2019 ◽  
Author(s):  
Seung In Seo ◽  
Byoung Joo ◽  
Jin Gu Kang ◽  
Hyoung Su Kim ◽  
Myoung Kuk Jang ◽  
...  

Abstract Background Clarithromycin resistance in Helicobacter pylori (H. pylori) is associated with point mutations in the 23S ribosomal RNA (rRNA) gene. A sequencing-based method can detect more point mutations than a polymerase chain reaction (PCR)-based method. We investigated the point mutations in the 23S rRNA genes of patients infected with clarithromycin-resistant H. pylori and compared the H. pylori eradication rates based on the identified clinically significant point mutations. Methods A total of 431 adult patients with H. pylori infection were retrospectively recruited in Kangdong Sacred Heart Hospital in 2017 and 2018. Patients who did not have point mutations related to clarithromycin resistance and/or had clinically insignificant point mutations were treated with PAC (proton pump inhibitor, amoxicillin, clarithromycin) for 7 days, while patients with clinically significant point mutations were treated with PAM (proton pump inhibitor, amoxicillin, metronidazole) for 7 days. H. pylori eradication rates were compared between the two groups. Results Sequencing-based detection of point mutations identified four mutations that were considered clinically significant (A2142G, A2142C, A2143G, A2143C), while all the other mutations were considered clinically insignificant. The clarithromycin resistance rate was 21.3% in the overall group of patients. A2143G was the most clinically significant point mutation (84/431, 19.5%), while T2182C was the most clinically insignificant point mutation (283/431, 65.7%). The H. pylori eradication rate in the overall group of patients was 83.7%, and the 7-day PAM-treated clarithromycin-resistance group showed a significantly lower eradication rate than the 7-day PAC-treated nonresistance group [ITT; 55.4% (51/92) vs. 74.3% (252/339), P=0.001, PP; 66.2% (51/77) vs. 88.4% (252/285), P=0.0001]. Conclusions There were significantly lower eradication rates in the patients with clarithromycin-resistant H. pylori as identified by the sequencing of point mutations in the 23S rRNA gene when treated with PAM for 7 days. A future study comparing treatment regimens in clarithromycin-resistant H. pylori-infected patients may be necessary.


QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Sameh Mohamed Fahiem Ghaly ◽  
Hany Ali Hussien Abd El-Rahman ◽  
Mohamed Osama Aly Aly ◽  
Ahmed Medhat Youssef Ibrahim Youssef

Abstract Background Antibiotic resistance in Helicobacter pylori is the major cause of eradication failure. Prevalence of H.pylori antibiotic resistance is increasing worldwide, and it is the main factor affecting efficacy of current therapeutic regimens. Our aim is to investigate H.pylori resistant patients toward Levofloxacin and detect the most effective antibiotic in eradication of H.pylori. Objective To investigate H.pylori resistant patients toward Levofloxacin including regimens and to detect the most effective antibiotic in H.pylori eradication. Patients and Methods The present study aimed to investigate the Susceptibility of Levofloxacin Resistant H.pylori in patients who had been diagnosed and received any regimen including Levofloxacin and still signs and symptoms of H.pylori infection not releaved and after proper time of stoppage of PPI and antibiotics H.pylori Ag in stool still positive at the period from January 2019 to February 2020. Results In the present study we found a wide spectrum of resistance to rates of H. pylori, from nearly negligible rates of Rifampicin (0%), Imipenem (0%), Cefotaxime (2%), Tetracycline (6%), Doxycycline(10%), and Amoxicillin(38%). To high rates resistance to Metronidazole (100%), Erythromycin (72%), Clarithromycin (68%), Azithromycin (60%), Ciprofloxacin (52%), and Levofloxacin (48%). Conclusion Helicobacter pylori is the most common chronic bacterial infection in humans. Antibiotic resistance is a major issue nowadays. Prior use of macrolide antibiotics or metronidazole appears to increase the risk of H. pylori resistance. Clarithromycin resistance appears to be an "absolute" condition that can not be overcome by increasing the macrolide dose. Levofloxacin resistance seems to be increasing. Culture and susceptibility should be done before starting second line treatment.


Diagnostics ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 759
Author(s):  
Monika Maria Biernat ◽  
Aldona Bińkowska ◽  
Łukasz Łaczmański ◽  
Paweł Biernat ◽  
Paweł Krzyżek ◽  
...  

Antibiotic resistance of Helicobacter pylori is currently a global issue. The aim of this study was to analyze actual antibiotic resistance rates of H. pylori strains isolated from children with primary infections and to compare the incidence of mutations that determine resistance to clarithromycin (CH) and metronidazole (MET) in children with different clinical diagnoses. A total of 91 H. pylori strains were isolated from 108 children with primary infections. Drug susceptibility testing of the strains was performed using E-test method. Classical sequencing of DNA fragments was used to detect point mutations for CH and MET resistance. Resistance to CH was detected in 31% of isolated strains (28/91), while resistance to MET and CH was detected in 35% (32/91) of strains. A2143G was the most frequently detected mutation and was dominant among strains isolated from children with peptic ulcer disease (80%). Mutations in the rdxA gene were found significantly more frequently among MET-resistant strains than MET-sensitive strains (p = 0.03, Chi2 = 4.3909). In children, a higher frequency of H. pylori multiresistant strains was observed compared with the previous study in the same area. Differences were found in the occurrence of point mutations among H. pylori strains resistant to CH isolated from children with different clinical diagnoses.


2013 ◽  
Vol 208 (7) ◽  
pp. 1123-1130 ◽  
Author(s):  
H. J. Lee ◽  
J. I. Kim ◽  
D. Y. Cheung ◽  
T. H. Kim ◽  
E. J. Jun ◽  
...  

2019 ◽  
Vol 56 (4) ◽  
pp. 361-366
Author(s):  
Cristian PARRA-SEPÚLVEDA ◽  
José S MERINO ◽  
Katia SÁEZ-CARRILLO ◽  
Carlos GONZÁLEZ ◽  
Apolinaria GARCÍA-CANCINO

ABSTRACT BACKGROUND: Helicobacter pylori infection in Chile remains as a public and private health-care system’s challenge, with a prevalence of the infection over 70%. Nowadays, antibiotic treatment of the infection is mandatory to prevent the arising of severe associated diseases but failures in the eradication therapy mainly due to clarithromycin resistance has been observed worldwide and first line eradication therapy seems to be not effective anymore in several geographical areas. Thus, health-care systems are committed to maintain an epidemiological surveillance upon the evolution of the antibiotic resistance of this priority 2 pathogen. OBJECTIVE: This work reports a 10 years surveillance of the primary antibiotic resistance of H. pylori clinical isolates at the Biobío region-Chile, and the evolution of resistance toward amoxicillin, clarithromycin, levofloxacin, metronidazole, and tetracycline among the species. METHODS: H. pylori strains were investigated during the periods 2005-2007 (1435 patients analysed) and 2015-2017 (220 patients analysed) by inoculating a saline homogenate biopsy onto the surface of Columbia agar (Oxoid, Basingstoke, UK) - supplemented with 7% horse red blood cells plus DENT inhibitor (Oxoid, Basingstoke, UK) - following by incubation at 37ºC under 10% CO2 atmosphere for five days. Antibiotic resistance pattern of the isolates was assessed using the disk diffusion test in Müeller-Hinton agar supplemented with 7% horse red blood cells followed by incubation for further three days under 10% CO2 atmosphere. Statistical analysis was done using the SPSS v22 software and P values <0.05 were considered statistically significant. RESULTS: A total of 41% of 1435 patients were detected to be infected with H. pylori by bacteriological culture in 2005-2007 period, meanwhile 32.7% from 220 patients were also infected in 2015-2017 period. The clinical isolates of H. pylori are mostly susceptible to amoxicillin and tetracycline (both over 98% of strains), but less susceptible to levofloxacin in both periods analysed (over 79% of the strains). On the other hand, metronidazole continuous showing the highest score of resistant isolates (over 40% of resistant strains), although an 18% fewer resistant strains were observed in 2015-2017 period. Clarithromycin, the key antibiotic in eradication therapies, has an increased frequency of resistant strain isolated in the decade (22.5% in 2005-2007 and 29.2% in 2015-2017). Multidrug resistant strains (two, three and four antibiotics) were also detected in both periods with the highest scores for simultaneous resistance to clarithromycin-metronidazole (18%) and clarithromycin-metronidazole-levofloxacin (12.5%) resistant strains. According to gender, the isolates resistant to amoxicillin, clarithromycin and metronidazole were more frequent in female, with a specific increment in amoxicillin and clarithromycin resistance. CONCLUSION: The frequency of clarithromycin resistance (29.2%) detected in 2015-2017 suggests that conventional triple therapy is no longer effective in this region.


2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Zehra Kipritci ◽  
Yesim Gurol ◽  
Gulden Celik

Aim. H. pylori is a bacterial pathogen in the human stomach which infects about 50% of the world population. Untreated infection can lead to various diseases leading to cancer. Some of the H. pylori strains are asymptomatic, but some of them cause more severe diseases. Standard treatment protocol used for the treatment of H. pylori infection is triple therapy, which includes omeprazole as a proton pump inhibitor (PPI) and two antibiotics usually consist of amoxicillin and clarithromycin or metronidazole. In the recent years, because of the increase in the rate of antibiotic resistance, the eradication rate has decreased. Materials and Methods. We evaluated 140 patients who applied to a university hospital gastroenterology department and underwent biopsy during endoscopy. In these patients, we analysed floroquinolone and clarithromycin resistance using the GenoType® HelicoDR (Hain Life Science, Germany). We also used the real-time method for clarithromycin resistance. Results. We found the number and rate of floroquinolone resistance as 20 (25.6%) and clarithromycine resistance as 31 (39.7%). With the real-time PCR method, we detected clarithromycine resistance in 26 (33.3%) patients. These results were not statistically significant. Discussion and Conclusion. Our results show similarity to the other studies held in our country. There should be more studies for the policy of eradication through our country.


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