scholarly journals Diagnosis of Helicobacter pylori Infection in a Routine Testing Workflow: Effect of Bacterial Load and Virulence Factors

2021 ◽  
Vol 10 (13) ◽  
pp. 2755
Author(s):  
Nabil Gastli ◽  
Margaux Allain ◽  
Dominique Lamarque ◽  
Vered Abitbol ◽  
Annick Billoët ◽  
...  

Reliable diagnostic methods are mandatory for effective management of Helicobacter pylori infection. Histology and culture are the most common invasive methods in current practice, even if molecular methods are gaining in importance. The performance of these conventional methods varies significantly. We conducted a retrospective study of 1540 adults and 504 children with gastric biopsies taken during endoscopy to assess the impact of bacterial load and the cagA virulence factor on the performance of H. pylori infection testing. The association between virulence and histology findings was also investigated. With 23S rRNA qPCR confirmed by glmM amplification as the gold standard, culture and histology had lower sensitivity, 74.4% and 73.3%, respectively. However, their sensitivity was enhanced (>90%) in biopsies with high bacterial load (qPCR Ct < 30). Positive cagA status of the strain was associated with high bacterial load (94.9%), thus resulting in more frequent positive culture (94.3%) and H. pylori histology detection (91.7%) and more severe lesions on histology (p < 0.001). Conversely, the cagA status of the strains was negative in 110/119 (92.4%) of biopsies with low bacterial load (qPCR Ct < 30), 82/90 (91.1%) with negative H. pylori histology detection and 119/131 (90%) with negative culture findings (p < 0.001). This study highlights the low sensitivity of conventional culture and histology that may lead to false negative diagnosis if used alone. H. pylori quantification associated with cagA genotyping in routine workflow are essential for a sensitive and reliable diagnosis, to identify patients at high risk and to manage eradication therapies.

2018 ◽  
Vol 7 (5) ◽  
pp. 217-224
Author(s):  
Zouaouia Chama ◽  
Khedoudj Kanoun ◽  
Fatima Zohra Elkadi ◽  
Kara Turqui Douidi ◽  
Noria Harir ◽  
...  

Helicobacter pylori infection concerns half of the world’s population, mainly in developing countries. It causes several gastrodudenal pathologies such as gastritis, ulcer and gastric adenocarcinoma. The aim of our study was to determine the prevalence of H.pylori infection and to assess the impact of different epidemiological factors as well as principal gastric diseases associ-ated to this infection. We underwent a prospective study during 18 months (month 2016-month 2017) which implicated 201 symptomatic patients for gastric fiboptic endoscopy at the level of Sidi Bel Abbes University hospital. We collected patients’ biopsies to perform a histological study and H. pylori culture. H. pylori identification was carried out based on bacteriological and biochemical analysis. The middle age of our population was (47.29 ±15.97ans) and the sex-ratio =0,8. The global prevalence of Helicobacter pylori infection is of 61.2% (123/201). This rate, after a statistic analysis, seems to be significantly related to age. It is particularly high especially for patients belonging to age range (20-30)-(51-60) years. The gender did not affect the infection prevalence that is more frequent in the gastritis case. We noticed also that HP infection prevalence was important in SBA the hospital. The range age (20-30)-(51-60) years had the highest prevalence of H. pylori and of gastritis which might be a risky ground of gastric cancer appearance. The ulcer pathology maximal rate concerned the group of 51 to 60 years. Above this age, this rate dropped whereas the number of patients suffering from gastric cancer, which presents an important rate in our study, increase for the group of 61-70 years.


Author(s):  
Majid Taati Moghadam ◽  
Zahra Chegini ◽  
Amin Norouzi ◽  
Amin Sadeghi Dosari ◽  
Aref Shariati

Background: Helicobacter pylori causes dangerous and deadly diseases such as gastric cancer and duodenal ulcers. Eradication and treatment of this bacterium are very important due to the deadly diseases caused by H. pylori and the high cost of treatment for countries. So, we present a complete list of the most important causes of failure in the treatment and eradication of H. pylori, and addresses new therapeutic methods that may be effective in controlling this bacterium in the future. Results: Many efforts have been made to control and eradicate this bacterium over the years, but no success has been achieved since its eradication is a complex process affected by the bacterial properties and host factors. Previous studies have shown that various factors are involved in failure to eradicate H. pylori, such as new genotypes of the bacterium with higher pathogenicity, inappropriate patient cooperation, mutations, biofilm formation and dormant forms that cause antibiotic resistance, acidic stomach pH, high bacterial load, smoking, immunosuppressive features and intracellular occurrence of H. pylori. On the other hand, recent studies reported that the use of probiotics, nanoparticles, antimicrobial peptides, natural product and vaccine can be helpful in the treatment and eradication of H. pylori infections. Conclusion: Eradication of H. pylori is crucial for the treatment of important diseases such as gastric cancer. Therefore, it seems that identifying the failure causes of treating this bacterium can be helpful in controlling the infections. Besides, further studies on new therapeutic strategies may help eradicate H. pylori in the future.


2014 ◽  
Vol 63 (5) ◽  
pp. 703-709 ◽  
Author(s):  
Hanafiah Alfizah ◽  
Ahmad Norazah ◽  
Razlan Hamizah ◽  
Mohamed Ramelah

Antibiotic resistance is increasing worldwide, and it has been regarded as the main factor reducing the efficacy of Helicobacter pylori therapy. The aim of this study was to determine the phenotype and genotype of antibiotic-resistant strains of H. pylori in the Malaysian population and to evaluate the impact of antibiotic resistance to eradication outcome. One hundred and sixty-one H. pylori isolates were analysed in this study. Metronidazole, clarithromycin, fluoroquinolone, amoxicillin and tetracycline susceptibilities were determined by Etest. PCR followed by DNA sequencing was carried out to determine mutations. The medical records of the patients infected with resistant strains were reviewed to determine the eradication outcome. Metronidazole resistance was encountered in 36.6 % of H. pylori isolates, whereas clarithromycin and fluoroquinolone resistance was observed in 1.2  and 1.9 % of isolates, respectively. All strains tested were susceptible to amoxicillin and tetracycline. Frameshift and nonsense mutations in rdxA and frxA genes resulting in stop codons contributed to metronidazole resistance, which leads to reduced eradication efficacy. A2142G and A2143G mutations of 23S rRNA were identified as causing failure of the eradication therapy. Mutation at either codon 87 or 91 of the gyrA gene was identified in fluoroquinolone-resistant strains. However, the effect of resistance could not be assessed. This study showed that frameshift and nonsense mutations in rdxA or frxA genes and point mutations in the 23S rRNA affected the efficacy of H. pylori eradication therapy.


2005 ◽  
Vol 19 (7) ◽  
pp. 412-414 ◽  
Author(s):  
Kevan Jacobson

While several studies have demonstrated a decline in the overall prevalence of Helicobacter pylori infection in developed countries, there is variability in the burden of infection linked to socioeconomic status and living conditions. Improved socioeconomic status, living conditions and the availability of H pylori-eradication therapy have been associated with a lower prevalence of infection in First World populations, yet immigrants and indigenous people continue to have a high burden of H pylori infection and disease. Although the changing prevalence of H pylori infection in children has been recognized in a few reports, further studies are required to determine the impact of H pylori infection in this population. Moreover, additional studies are required for those populations at risk.


2019 ◽  
Vol 91 (2) ◽  
pp. 16-24 ◽  
Author(s):  
D S Bordin ◽  
Yu V Embutnieks ◽  
L G Vologzhanina ◽  
T A Ilchishina ◽  
I N Voynovan ◽  
...  

The multicenter prospective observational study initiated by the European Helicobacter and Microbiota Study Group (EHMSG) is conducted in 27 countries in Europe. The data from the Russian part of the European registry for the management of Helicobacter pylori infection (European Registry on the management of Helicobacter pylori infection, protocol: “Hp-EuReg”) allows us to analyze the real clinical practice of diagnosis and treatment of H. pylori and compare it with international recommendations. Materials and methods. A comparative analysis of the data entered in the register by the Russian research centers “Hp-EuReg”, in the period from 2013 to 2018, was conducted. Results and discussion. Invasive diagnostic methods prevail for the primary diagnosis of H. pylori [histology - 20.3% (in 2013 year) - 43.9% (in 2018 year), rapid urease test - 31.7% and 47.8% respectively]. The most popular mode of eradication therapy is a 10-day triple therapy (62.8-76.2%), the effectiveness of which does not exceed 79% (per protocol). Invasive tests (histology) are the leading method for control the effectiveness of therapy, however, there is a tendency towards a wider use of non-invasive methods (H. pylori stool antigen - from 17% in 2013 to 29.3% in 2018 and urea breath test from 6.9 to 18.3%, respectively). Serological test to control the effectiveness of eradication is still used from 8.2% (2013) to 6.1% (2018). Eradication therapy was not performed in 28% of patients throughout the entire observation period. Conclusion. In Russia, despite approved domestic and international recommendations, deviations in clinical practice persist, both during eradication therapy and in monitoring the effectiveness of eradication therapy.


2007 ◽  
Vol 135 (1-2) ◽  
pp. 26-30
Author(s):  
Natasa Opavski ◽  
Milan Spuran ◽  
Slobodanka Djukic ◽  
Vera Mijac ◽  
Lazar Ranin

Introduction: Helicobacter pylori induces gastric inflammation in host and such gastritis increases the risk of gastric and duodenal ulceration as well as adenocarcinoma. Because peptic ulcer disease is the major cause of morbidity, accurate diagnosis of H. pylori infection is very important. Unfortunately, there is no gold standard among diagnostic tests for Helicobacter infections. If gastroscopy is performed, histopathology and urease test are the most often used. Still, culturing of this bacterium is essential for drug susceptibility testing and analysis of virulence factors. Objective The aim of this study was to compare three diagnostic procedures - histopathology, urease test and culture, which are used to verify H. pylori infection. Method Three pairs of gastric mucosal biopsy specimens were collected from each of 28 dyspeptic patients undergoing endoscopy. Nineteen patients were not pretreated with antibiotics, while nine had received eradication therapy earlier. One pair of biopsy specimens was used for histopathologic examination, the second for urease test and the third was simultaneously cultured on nonselective and selective solid media. Isolate was identified as H. pylori on the basis of colony morphology, morphological properties and biochemical tests. Results In 14 out of 28 patients, H. pylori infection was confirmed on the basis of results of all diagnostic procedures. The concordance of these three methods was very good, because the results of histopathology, urease test and culture corresponded in 26 from 28 patients. Conclusion The conclusion of our study is that culture, as the method with high degree of concordance with other two procedures and the only that can give information on drug susceptibility of Helicobacter, is recommended for diagnosis of Helicobacter pylori infection along with histopathology and urease test.


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