Treatment of <i>Helicobacter pylori</i> infection and factors influencing eradication

Qasim, Asghar; O’Moráin, Colm

doi:10.1046/j.1365-2036.2002.0160s1024.x

Cited by 76 publications

(49 citation statements)

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“…Resistance to metronidazole, a significant cause of H. pylori treatment failure (11)(12)(13), is becoming increasingly common in many countries worldwide (14,15). It is now accepted that metronidazole resistance is predominantly caused by mutations in rdxA (16)(17)(18)(19) and that mutations in frxA enhance the resistance of rdxA gene mutations (20)(21)(22)(23).…”

Section: Discussionmentioning

confidence: 99%

“…Metronidazole has been used widely in combination therapies, such as metronidazolebased triple therapy, concomitant therapy, and bismuth-containing quadruple therapy, to eradicate this bacterium (5,9,10). Although treatment success depends on several factors, such as smoking status and patient compliance, antibiotic resistance is the major cause of treatment failure (11)(12)(13). However, along with clarithromycin resistance, resistance to metronidazole has arisen independently and is becoming increasingly common (14,15).…”

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confidence: 99%

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Search for Novel Candidate Mutations for Metronidazole Resistance in Helicobacter pylori Using Next-Generation Sequencing

Binh

Suzuki

Trang

et al. 2015

Antimicrob Agents Chemother

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Metronidazole resistance is a key factor associated with Helicobacter pylori treatment failure. Although this resistance is mainly associated with mutations in the rdxA and frxA genes, the question of whether metronidazole resistance is caused by the inactivation of frxA alone is still debated. Furthermore, it is unclear whether there are other mutations involved in addition to the two genes that are associated with resistance. A metronidazole-resistant strain was cultured from the metronidazole-susceptible H. pylori strain 26695-1 by exposure to low concentrations of metronidazole. The genome sequences of both susceptible and resistant H. pylori strains were determined by Illumina next-generation sequencing, from which putative candidate resistance mutations were identified. Natural transformation was used to introduce PCR products containing candidate mutations into the susceptible parent strain 26695-1, and the metronidazole MIC was determined for each strain. Mutations in frxA (hp0642), rdxA (hp0954), and rpsU (hp0562) were confirmed by the Sanger method. The mutated sequence in rdxA was successfully transformed into strain 26695-1, and the transformants showed resistance to metronidazole. The transformants containing a single mutation in rdxA showed a low MIC (16 mg/liter), while those containing mutations in both rdxA and frxA showed a higher MIC (48 mg/ liter). No transformants containing a single mutation in frxA or rpsU were obtained. Next-generation sequencing was used to identify mutations related to drug resistance. We confirmed that the mutations in rdxA are mainly associated with metronidazole resistance, and mutations in frxA are able to enhance H. pylori resistance only in the presence of rdxA mutations. Moreover, mutations in rpsU may play a role in metronidazole resistance. Helicobacter pylori is a spiral-shaped Gram-negative bacterium that infects more than half of the world's population and is a major cause of chronic gastritis, peptic ulcer diseases, gastric cancer, and mucosa-associated lymphoid tissue lymphoma (1, 2). The eradication of H. pylori not only improves peptic ulcer healing but also prevents its recurrence and reduces the risk of developing gastric cancer (3-5). Furthermore, other H. pylori-related disorders, such as mucosa-associated lymphoid tissue lymphoma, atrophic gastritis, and intestinal metaplasia, have been shown to regress after antimicrobial therapy (6-8). Metronidazole has been used widely in combination therapies, such as metronidazolebased triple therapy, concomitant therapy, and bismuth-containing quadruple therapy, to eradicate this bacterium (5, 9, 10). Although treatment success depends on several factors, such as smoking status and patient compliance, antibiotic resistance is the major cause of treatment failure (11-13). However, along with clarithromycin resistance, resistance to metronidazole has arisen independently and is becoming increasingly common (14, 15).Resistance to metronidazole was described previously and is predominantly associated with mutation...

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Search for Novel Candidate Mutations for Metronidazole Resistance in Helicobacter pylori Using Next-Generation Sequencing

Binh

Suzuki

Trang

et al. 2015

Antimicrob Agents Chemother

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“…Poor compliance is one of the most important issues in treatment failure [41,42] . The occurrences of adverse effects such as taste disturbance, nausea and loose stools discourage patients from completing a course of therapy [43] .…”

Section: Patient-related Factors ( Fi G 3 )mentioning

confidence: 99%

‘Rescue’ Therapies for the Management of <i>Helicobacter pylori </i>Infection

Mario¹,

Cavallaro²,

Scarpignato

2006

Dig Dis

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Helicobacter pylori infection is the main cause of gastritis, gastroduodenal ulcer and gastric cancer and should be considered as a major public health issue. According to several international guidelines, first-line therapy for treating H. pylori infection consists of proton pump inhibitor (PPI) or ranitidine bismuth citrate (RBC) with any two antibiotics of amoxicillin, clarithromycin or metronidazole given for 7–14 days. However, even with the recommended treatment regimens, approximately 20% of patients will fail to obtain H. pylori eradication. The proportion of patients with first-line H. pylori therapy failure may be higher in clinical practice and it may increase thanks to diffusion of H. pylori treatment. The recommended second-line therapy is the quadruple regimen composed by tetracycline, metronidazole, bismuth salts and a PPI. However, the efficacy of this regimen is limited by poor patient’s compliance due to its side effects, number of tablets per day, and long duration. Moreover, bismuth and metronidazole are not available in all countries. Alternatively, a longer-lasting (i.e. 10–14 days) PPI or RBC triple therapy with two antibiotics has generally been used. In an empirical strategy, the choice of second line depends on the treatment initially used. If a clarithromycin-based regimen was administered in first line, a quadruple regimen or PPI (or RBC) triple therapy with metronidazole and amoxicillin (or tetracycline) should be suggested as a second line. In case of second-line treatment failure, the patient should be evaluated by a case-by-case approach. A susceptibility-guided strategy, if available, is recommended in order to choose the best third-line treatment. Culture can reveal the presence of H. pylori-sensitive strains to clarithromycin (the best effective) or other antimicrobials (such as amoxicillin, metronidazole and tetracycline). Conversely, in an empirical strategy, a third-line not yet used therapy, can reach a high success rate. PPI or RBC, amoxicillin and a new antimicrobial (e.g. rifabutin, levofloxacin or furazolidone) could be used. Several studies have obtained relatively good results with triple therapy combining PPI, rifabutin, and amoxicillin, although a reversible myelotoxicity as leukopenia and thrombocytopenia has been described. Preliminary good results were also achieved with triples PPI regimens combining levofloxacin and amoxicillin without important adverse effects. Furazolidone has also shown efficacy for H. pylori eradication, although untoward reactions could limit its use, especially when high doses are employed. Finally, in more than one H. pylori treatment failure, non-antimicrobial add-on medications (such as lactoferrin, probiotics and others) could be used with the aim either to improve the eradication rate or to minimize side effects.

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“…Both the acid and the bacteria irritate the lining and cause a sore, or ulcer Laurila et al 3 H. Pylori are able to survive in stomach acid because they secrete enzymes that neutralize the acid. This mechanism allows H. Pylori to make its way to the "safe" area-the protective mucous lining O'Morain et al 4 Enervating habits, the use of stimulants, excesses in eating and pleasurable enjoyments, using irritating substances like salt, pepper, vinegar, spices, hot sauces, alcohol, tobacco, cathartics, etc., lack of emotional poise, overwork or any natural or unnatural expenditure of nerve energy beyond the power of recuperation. Chronic gastritis is the culmination of a number of recurrences of acute gastritis with a continuous abuse of the stomach between crises Kaptan et al 2 Gastritis can be caused by infection, irritation, autoimmune disorders (disorders caused by the body's immune response against its own tissues), or backflow of bile into the stomach (bile reflux).…”

Section: Introductionmentioning

confidence: 99%

A clinical study of prevalence of helicobacter pylori in patients with gastritis

Rangaswamy

Rubby

2016

Int Surg J

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Background: Stomach infections with Helicobacter pylori mainly occur during childhood. If persistent, these may cause chronic gastritis often leading to peptic ulcer disease, later on in life. Ulcer is a sore or hole in the lining of the stomach or duodenum (the first part of the small intestine). Objective was to detect the prevalence of H. Pylori in patients with gastritis. Methods: This study involved 90 patients with gastritis who attended surgical outpatient as well as inpatient department of ESIC Medical college hospital from April 2014 to March 2016. Results: Endoscopy was carried for all patients to diagnose gastritis. Urease and Serum IgG anti H. Pylori antibodies used to detect the presence of H. Pylori in these patients. Ninety patients; 60 males (66.67%) and 30 females (36.33%) were infected with gastritis. The results showed that 53.33% of the patients gave positive results on urease test. The results showed that for screening and determining the clinical features of gastritis, at least one method for H. Pylori are required to give positive result in order to identify an infected patient with H. Pylori. Conclusions: There is an additional aspect to treatment of gastric ulcers, the one of health care providers and patient's awareness of the cause and most efficient treatments for this medical condition. Ulcers that presented until recently a life-long disease with only symptomatic relieve available, became an easily curable condition, when the right pathway of treatment is chosen.

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Treatment of Helicobacter pylori infection and factors influencing eradication

Cited by 76 publications

References 61 publications

Search for Novel Candidate Mutations for Metronidazole Resistance in Helicobacter pylori Using Next-Generation Sequencing

Search for Novel Candidate Mutations for Metronidazole Resistance in Helicobacter pylori Using Next-Generation Sequencing

‘Rescue’ Therapies for the Management of <i>Helicobacter pylori </i>Infection

A clinical study of prevalence of helicobacter pylori in patients with gastritis

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