**1. Introduction**

*Helicobacter pylori* is one of the most common human infections [1–3]. Infected patients develop chronic active gastritis in all cases, which can lead to peptic ulcer, atrophic gastritis, gastric cancer and gastric MALT-lymphoma [4–7]. Eradication of *H. pylori* can prevent longterm complications, or relapses of the disease. The treatment the infection is recognized as the primary prevention of gastric cancer.

The prevalence of *H. pylori* infection in the population has geographical distribution characteristics, determined by the level of hygiene, and can reach 80% [8]. According to a meta-analysis published in 2017, the number of people infected with *H. pylori* in the Russian Federation was estimated at 78.5% [9]. At the same time, the prevalence of infection in developed countries is decreasing. Thus, a recently published study showed, that about 40% of the population in Russia is infected, while the prevalence of *H. pylori* increases with age [10].

The recently published Maastricht VI Consensus proposed two strategies for selecting eradication therapy: individualized, based on antibacterial susceptibility, and empirical, in which data regarding local resistance of *H. pylori* to clarithromycin (<15% or >15%) are taken into account when choosing a treatment regimen and monitoring the effectiveness of schemes used in the particular region [4]. Therefore, the determination of *H. pylori* resistance

**Citation:** Medakina, I.; Tsapkova, L.; Polyakova, V.; Nikolaev, S.; Yanova, T.; Dekhnich, N.; Khatkov, I.; Bordin, D.; Bodunova, N. *Helicobacter pylori* Antibiotic Resistance: Molecular Basis and Diagnostic Methods. *Int. J. Mol. Sci.* **2023**, *24*, 9433. https:// doi.org/10.3390/ijms24119433

Academic Editors: Jean-Christophe Marvaud and Maria Teresa Mascellino

Received: 30 March 2023 Revised: 10 May 2023 Accepted: 19 May 2023 Published: 29 May 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

to antibiotics, primarily to clarithromycin, is extremely important for the implementation of these treatment strategies.

The efficacy of antibacterial drugs depends on the sensitivity of the bacteria to them. Currently, a major problem is the decreasing efficacy of therapy regimens, which is associated with the rise of antibiotic resistance in *H. pylori* strains. The prevalence of *H. pylori* resistance varies in different countries and depends on the overall frequency of antibiotic use.

The main objective of this study was to provide a comprehensive analysis of current state of research on the study of antibiotic resistance in *H. pylori*, the molecular mechanisms underlying its emergence, as well as an overview and comparison of methods used for resistance evaluation.

The structure of this article is presented in a diagram (Figure 1).

**Figure 1.** The structure of this article.
