Review
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 28, 2017; 23(16): 2870-2882
Published online Apr 28, 2017. doi: 10.3748/wjg.v23.i16.2870
Strategies used by helicobacter pylori to establish persistent infection
Amin Talebi Bezmin Abadi
Amin Talebi Bezmin Abadi, Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran 14115-111, Iran
Author contributions: Talebi Bezmin Abadi A designed the research, analyzed the data and wrote the article.
Conflict-of-interest statement: Author declares no conflict of interests for this article.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Amin Talebi Bezmin Abadi, PhD, Assistant Professor, Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran 14115-111, Iran. amin.talebi@modares.ac.ir
Telephone: +98-21-82884883 Fax: +98-21-82884883
Received: December 5, 2016
Peer-review started: December 6, 2016
First decision: January 10, 2017
Revised: February 1, 2017
Accepted: February 16, 2017
Article in press: February 16, 2017
Published online: April 28, 2017
Processing time: 143 Days and 17 Hours
Abstract

Helicobacter pylori (H. pylori) is a Gram-negative and motile bacterium that colonizes the hostile microniche of the human stomach, then persists for the host’s entire life, if not effectively treated. Clinically, H. pylori plays a causative role in the development of a wide spectrum of diseases including chronic active gastritis, peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Due to the global distribution of H. pylori, it is no exaggeration to conclude that smart strategies are contributing to adaptation of the bacterium to its permanent host. Thirty-four years after the discovery of this bacterium, there are still many unanswered questions. For example, which strategies help the bacterium to survive in this inhospitable microniche? This question is slightly easier to answer if we presume the same clinical concept for both persistent infection and disease. Understanding the mechanisms governing H. pylori persistence will improve identification of the increased risk of diseases such as gastric cancer in patients infected with this bacterium. A well-defined and long-term equilibrium between the human host and H. pylori allows bacterial persistence in the gastric microniche; although this coexistence leads to a high risk of severe diseases such as gastric cancer. To escape the bactericidal activity of stomach acid, H. pylori secretes large amounts of surface-associated and cytosolic urease. The potential to avoid acidic conditions and immune evasion are discussed in order to explain the persistence of H. pylori colonization in the gastric mucosa, and data on bacterial genetic diversity are included. Information on the mechanisms related to H. pylori persistence can also provide the direction for future research concerning effective therapy and management of gastroduodenal disorders. The topics presented in the current review are important for elucidating the strategies used by H. pylori to help the bacterium persist in relation to the immune system and the many unfavorable features of living in the gastric microniche.

Keywords: Helicobacter pylori; Gastric microniche; Persistent infection; Gastric cancer

Core tip:Helicobacter pylori (H. pylori) infections are thought to cause severe gastroduodenal disorders which are the main outcome of this interaction between the host and this microorganism. The bacterium has developed interesting strategies which allow it to efficiently colonize the gastric mucosa leading to persistent infection. In this review, we aim to look at the five major reported strategies leading to the persistent survival of H. pylori within gastric epithelial cells.