Preface

**Section 3 Helicobacter Pylori and Eradication Therapies 89**

Chapter 7 **Gastric Microbiota and Resistance to Antibiotics 91**

**pylori: From Nature to the Lab 109**

Maria Cristina L. Martins

**VI** Contents

Havnhøj Frandsen and Leif Percival Andersen

Chapter 8 **Nonantibiotic-Based Therapeutics Targeting Helicobacter**

Agnes Tving Stauning, Rie Louise Møller Nordestgaard, Tove

Paula Parreira, Catarina Leal Seabra, Daniela Lopes-de-Campos and

*Helicobacter pylori* (*H. pylori*) remains one of the most common worldwide human infections and, although its colonization is not a disease in itself, it is a condition that affects the relative risk of developing various clinical disorders of the upper gastrointestinal tract, such as chron‐ ic gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (MALT) lymphoma and gastric adenocarcinoma. Besides, in the last decades, the infection and its consequences pro‐ duced by this microorganism has been associated with the development of various extradi‐ gestive disorders, such as hepatobiliary, cardiovascular and pancreatic diseases, iron deficiency anemia, idiopathic thrombocytopenic purpura, skin diseases, among others.

Despite the bacteria infects half of the world population, most patients are asymptomatic for life, while only some will come to develop a digestive disease. Nevertheless, gastric cancer remains one of the principal causes of cancer death worldwide and *H. pylori* is consider as a class I carcinogen (International Agency for Research on Cancer – World Health Organization).

Transmission of *H. pylori* is still not entirely clarified, but human-to-human spread through oral-oral or fecal-oral route is thought to be most plausible. The infection is typically ac‐ quired during childhood and usually becomes a lifelong infection, if left untreated. The host certainly mounts an immune response, but it fails to clear the infection, allowing *H. pylori* to establish a persistent infection and a chronic inflammation.

In this book, compounded by eight chapters, important aspects of *H. pylori* were reported and the book divided into three following sections: "General aspects of *Helicobacter pylori* infection", "Virulence factors of *Helicobacter pylori"*, and "*Helicobacter pylori* and eradication therapy".

The first section comprehends four chapters, "*Helicobacter pylori*: an overview of an old hu‐ man microorganism", "Clinical manifestations of the *Epsilonproteobacter, Helicobacter pylori*", "Endoscopical aspects of *Helicobacter pylori* gastritis in children", and "The importance of *H. pylori* infection in liver diseases".

In the second section some important aspects regarding virulence factors of *H. pylori* were reported in two chapters, "VacA genotype" and "*Helicobacter pylori* genes jhp0940, jhp0945, jhp0947 and jhp0949 associated to gastroduodenal disease".

Finally, in the third section, two chapters explore aspects concerning the eradication treat‐ ment of *H. pylori* infection and possible resistance mechanisms to the antibiotics commonly used for this purpose, besides the use of natural medicines for eradication of this microor‐ ganism: "Gastric microbiota and resistance to antibiotics" and "Non-antibiotic based thera‐ peutics targeting *Helicobacter pylori*: from Nature to the lab".

"*Helicobacter pylori* – New Approaches of an Old Human Microorganism" is a book which will certainly provide an updated set of information in important aspects of this microor‐ ganism that has co-evolved with humans for over 60,000 years.

The editor expresses her thankfulness for the excellent work of the contributing authors. The editor thanks the entire In Tech Open Access publishing team for all its attention and sup‐ port, making possible the accomplishment of this book. The editor is especially thankful for the excellent support given by Ms. Lada Bozic in all the steps of this book.

#### **Dr. Bruna Maria Roesler**

**Section 1**

**General Aspects of Helicobacter Pylori Infection**

Pharmacist Biochemist Center of Diagnosis of Digestive Diseases School of Medical Sciences, State University of Campinas Campinas, São Paulo, Brazil **General Aspects of Helicobacter Pylori Infection**

"*Helicobacter pylori* – New Approaches of an Old Human Microorganism" is a book which will certainly provide an updated set of information in important aspects of this microor‐

The editor expresses her thankfulness for the excellent work of the contributing authors. The editor thanks the entire In Tech Open Access publishing team for all its attention and sup‐ port, making possible the accomplishment of this book. The editor is especially thankful for

> **Dr. Bruna Maria Roesler** Pharmacist Biochemist

Campinas, São Paulo, Brazil

Center of Diagnosis of Digestive Diseases

School of Medical Sciences, State University of Campinas

ganism that has co-evolved with humans for over 60,000 years.

VIII Preface

the excellent support given by Ms. Lada Bozic in all the steps of this book.

**Chapter 1**

**Provisional chapter**

**Introductory Chapter:** *Helicobacter pylori* **- An**

**Introductory Chapter:** *Helicobacter pylori* **- An** 

DOI: 10.5772/intechopen.88806

The human stomach is an unfriendly place for most infective bacteria probably due to the very low pH found in this place. However, the first isolation of a spiral-shaped, Gram-negative and microaerophilic bacterium in 1982 by Warren and Marshall [1] significantly changed the

Initially, this bacterium was named *Campylobacter pyloridis*, but analysis of nucleic acid sequence and ultrastructural studies besides the helical shape allowed differentiation of this genus to *Helicobacter*. Finally, the species was named *pylori* because it can be found most often

*Helicobacter pylori* (*H. pylori*) organisms are 2.5–5.0 μm long and 0.5–1.0 μm wide, with two to six unipolar-sheathed flagella, which are essential for bacterial motility [3]. It has been described that bacteria can exist in three different morphologic forms: the viable and culturable spiral form, the viable but nonculturable (VBNC) coccoid form which are less virulent,

Colonization with *H. pylori* is commonly acquired during childhood and induces chronic gastritis in all infected individuals unless specific treatment is given [5, 6]. While over 80% of infected subjects remain asymptomatic [7], *H. pylori* chronic infection has been associated with the development of various clinical disorders of the upper gastrointestinal tract, such as chronic gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric adenocarcinoma [8]. In fact, *H. pylori* infection is a significant risk factor for the development of gastric cancer, and bacterium is classified as a group I carcinogen by

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

**Overview of an Old Human Microorganism**

**Overview of an Old Human Microorganism**

Additional information is available at the end of the chapter

Bruna Maria RoeslerAdditional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.88806

Bruna Maria Roesler

**1. Introduction**

concepts of gastric microbiology.

in the antral mucosa, near the pylorus [2].

the World Health Organization [9].

and the nonviable degenerative *H. pylori* form [4].

#### **Chapter 1 Provisional chapter**

#### **Introductory Chapter:** *Helicobacter pylori* **- An Overview of an Old Human Microorganism Introductory Chapter:** *Helicobacter pylori* **- An Overview of an Old Human Microorganism**

DOI: 10.5772/intechopen.88806
