Antibiotic Resistance Prevalence and Trends in Patients Infected with Helicobacter pylori in the Period 2013-2020: Results of the European Registry on H. pylori Management (Hp-EuReg).

Background: Bacterial antibiotic resistance changes over time depending on multiple factors; therefore, it is essential to monitor the susceptibility trends to reduce the resistance impact on the effectiveness of various treatments. Objective: To conduct a time-trend analysis of Helicobacter pylori resistance to antibiotics in Europe. Methods: The international prospective European Registry on Helicobacter pylori Management (Hp-EuReg) collected data on all infected adult patients diagnosed with culture and antimicrobial susceptibility testing positive results that were registered at AEG-REDCap e-CRF until December 2020. Results: Overall, 41,562 patients were included in the Hp-EuReg. Culture and antimicrobial susceptibility testing were performed on gastric biopsies of 3974 (9.5%) patients, of whom 2852 (7%) were naive cases included for analysis. The number of positive cultures decreased by 35% from the period 2013-2016 to 2017-2020. Concerning naïve patients, no antibiotic resistance was found in 48% of the cases. The most frequent resistances were reported against metronidazole (30%), clarithromycin (25%), and levofloxacin (20%), whereas resistances to tetracycline and amoxicillin were below 1%. Dual and triple resistances were found in 13% and 6% of the cases, respectively. A decrease (p < 0.001) in the metronidazole resistance rate was observed between the 2013-2016 (33%) and 2017-2020 (24%) periods. Conclusion: Culture and antimicrobial susceptibility testing for Helicobacter pylori are scarcely performed (<10%) in Europe. In naïve patients, Helicobacter pylori resistance to clarithromycin remained above 15% throughout the period 2013-2020 and resistance to levofloxacin, as well as dual or triple resistances, were high. A progressive decrease in metronidazole resistance was observed.

Comparison of image analysis software packages in the assessment of adhesion of microorganisms to mucosal epithelium using confocal laser scanning microscopy.

We have compared current image analysis software packages in order to find the most useful one for assessing microbial adhesion and inhibition of adhesion to tissue sections. We have used organisms of different sizes, the bacterium Helicobacter pylori and the yeast Candida albicans. Adhesion of FITC-labelled H. pylori and C. albicans was assessed by confocal microscopy. Four different Image analysis software packages, NIH-Image, IP Lab, Image Pro+, and Metamorph, were compared for their ability to quantify adhesion of the two organisms and several quantification methods were devised for each package. For both organisms, the dynamic range that could be detected by the software packages was 1x10(6)-1x10(9) cells/ml. Of the four software packages tested, our results showed that Metamorph software, using our 'Region of Interest' method, with the software's 'Standard Area Method' of counting, was the most suitable for quantifying adhesion of both organisms because of its unique ability to separate clumps of microbial cells. Moreover, fewer steps were required. By pre-incubating H. pylori with the glycoconjugate Lewis b-HSA, an inhibition of binding of 48.8% was achieved using 250 mug/ml Lewis b-HSA. The method we have devised using Metamorph software, provides a simple, quick and accurate way of quantifying adhesion and inhibition of adhesion of microbial cells to the epithelial surface of tissue sections. The method can be applied to organisms ranging in size from small bacteria to larger yeast cells.

Non-invasive tests for the diagnosis of H. pylori infection.

Helicobacter pylori infection can be diagnosed by invasive techniques requiring endoscopy and biopsy (eg, histological examination, culture, polymerase chain reaction) and by non-invasive techniques such as serology, urea breath test, urine/blood test, or detection of H. pylori antigen in stool specimen. Some non-invasive tests, such as the urea breath test and the stool antigen test, detect active infection; these are called "active tests." Non-invasive tests (eg, serology) are markers of exposure to H. pylori but do not indicate if active infection is ongoing; these are called "passive tests." Non-invasive test-and-treat strategies are widely recommended in primary care settings. The choice of an appropriate test depends on the pre-test probability of infection, the characteristics of the test being used, and the cost-effectiveness of the test. This article reviews available non-invasive tests.