Where to Biopsy to Detect Helicobacter pylori and How Many Biopsies Are Needed to Detect Antibiotic Resistance in a Human Stomach

Abstract

This study aims to determine the gastric distribution, density, and diversity of Helicobacter pylori infection. Subtotal resection of the stomachs of three H. pylori-infected and asymptomatic obese patients were collected after a sleeve gastrectomy. Distribution and density of H. pylori were determined using culture and RT-PCR on multiple gastric sites (88, 176, and 101 biopsies per patient). Diversity of H. pylori strains was studied using antibiotic susceptibility testing, random amplified polymorphism DNA (RAPD) typing and cagA gene detection on single-colony isolates (44, 96, and 49 isolates per patient). H. pylori was detected in nearly all analyzed sites (354/365 biopsies, 97%). Antral density was higher in one patient only. The three stomachs were almost exclusively infected by an antibiotic-susceptible strain. One clarithromycin-resistant isolate in one biopsy was detected in two stomachs (1/44 and 1/49 isolates), while in the third one, eight (8/96 isolates) metronidazole-resistant isolates were detected. DNA typing showed infection with cagA-negative strains for one patient, cagA-positive strains for a second patient and the third patient was infected with two different strains of distinct cagA genotypes. Infection with H. pylori is shown to spread to the whole surface of the stomach, but a possibility of minor sub-population of antibiotic-resistant clones, undetectable in routine practice.

Trend of changes in antibiotic resistance in Helicobacter pylori from 2013 to 2019: a multicentre report from Taiwan

“…Pichon et al described the difference between gastric distribution, density and diversity of H. pylori in the stomach antrum and corpus, as these regions could include different levels of resistance. 20 This study observed that no specific area in the stomach could be highlighted with the absence of H. pylori detection, suggesting that a single biopsy could be enough for H. pylori detection.…”

“…However, the non-invasive Amplidiag H. pylori ClariR assay developed by Mobidiag (Espoo, Finland) for the detection of H. pylori and clarithromycin resistance with stool samples could be promising in the future. 20 In conclusion, primary, secondary and tertiary antibiotic resistance to clarithromycin, levofloxacin and metronidazole in H. pylori has been increasing in Taiwan since 2013. Treatment should be targeted for eradication success rates of more than 90%.…”

“…However, the non-invasive Amplidiag H. pylori ClariR assay developed by Mobidiag (Espoo, Finland) for the detection of H. pylori and clarithromycin resistance with stool samples could be promising in the future. 20 …”

Direct detection of Helicobacter pylori from biopsies of patients in Lagos, Nigeria using real-time PCR—a pilot study

“…The detection of H. pylori in biopsies collected from the antrum and corpus is widely reported. Pichon et al [ 14 ], reported the detection of H. pylori in both biopsies of antrum and corpus obtained from patients with H. pylori infection. However, in this present study there was zero detection of H. pylori in the corpus of two patients in which H. pylori was detected in their antrum biopsy samples.…”

A Retrospective Experience of Helicobacter pylori Histology in a Large Sample of Subjects in Northern Italy

“…The sensitivity of the Giemsa stain for the detection of H. pylori is about 93%, while its specificity is about 100% [ 9 ]. Proton pump inhibitors (PPI) are stopped at least two weeks before gastroscopy (this is to improve the accuracy of H. pylori detection in patients undergoing biopsies in the antrum only [ 10 ])…”