Minireviews
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 7, 2019; 25(37): 5578-5589
Published online Oct 7, 2019. doi: 10.3748/wjg.v25.i37.5578
Pathogenesis and clinical management of Helicobacter pylori gastric infection
Breno Bittencourt de Brito, Filipe Antônio França da Silva, Aline Silva Soares, Vinícius Afonso Pereira, Maria Luísa Cordeiro Santos, Mariana Miranda Sampaio, Pedro Henrique Moreira Neves, Fabrício Freire de Melo
Breno Bittencourt de Brito, Filipe Antônio França da Silva, Aline Silva Soares, Vinícius Afonso Pereira, Maria Luísa Cordeiro Santos, Mariana Miranda Sampaio, Pedro Henrique Moreira Neves, Fabrício Freire de Melo, Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
Author contributions: All authors equally contributed to this paper with conception and design of the study, literature review and analysis, drafting and critical revision and editing, and final approval of the final version; All authors agree to be accountable for all aspects of the work in ensuring that questions that related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Conflict-of-interest statement: All authors declare no potential conflicts of interest.
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/
Corresponding author: Fabrício Freire de Melo, PhD, Postdoctoral Fellow, Professor, Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Rua Hormindo Barros, 58, Quadra 17, Lote 58, Vitória da Conquista 45029-094, Bahia, Brazil. freiremelo@yahoo.com.br
Telephone: +55-77-991968134
Received: June 15, 2019
Peer-review started: June 17, 2019
First decision: July 21, 2019
Revised: August 14, 2019
Accepted: August 19, 2019
Article in press: July 21, 2019
Published online: October 7, 2019
Abstract

Helicobacter pylori (H. pylori) is a gram-negative bacterium that infects approximately 4.4 billion individuals worldwide. However, its prevalence varies among different geographic areas, and is influenced by several factors. The infection can be acquired by means of oral-oral or fecal-oral transmission, and the pathogen possesses various mechanisms that improve its capacity of mobility, adherence and manipulation of the gastric microenvironment, making possible the colonization of an organ with a highly acidic lumen. In addition, H. pylori presents a large variety of virulence factors that improve its pathogenicity, of which we highlight cytotoxin associated antigen A, vacuolating cytotoxin, duodenal ulcer promoting gene A protein, outer inflammatory protein and gamma-glutamyl transpeptidase. The host immune system, mainly by means of a Th1-polarized response, also plays a crucial role in the infection course. Although most H. pylori-positive individuals remain asymptomatic, the infection predisposes the development of various clinical conditions as peptic ulcers, gastric adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. Invasive and non-invasive diagnostic methods, each of them with their related advantages and limitations, have been applied in H. pylori detection. Moreover, bacterial resistance to antimicrobial therapy is a major challenge in the treatment of this infection, and new therapy alternatives are being tested to improve H. pylori eradication. Last but not least, the development of effective vaccines against H. pylori infection have been the aim of several research studies.

Keywords: Helicobacter pylori, Virulence factors, Immune response, Antibiotics, Vaccines

Core tip:Helicobacter pylori (H. pylori) is a bacterium that infects more than half of the world’s population. The mechanisms of such infections are complex and deeply studied. In addition, the clinical outcomes are variable and depend on both pathogen and host characteristics. Moreover, the adequate clinical management by means of proper diagnosis and effective treatment is crucial for reaching success in bacterial eradication. This article aims to provide a broad overview of H. pylori infection, from pathogenesis to clinical management.