Related Experiment Video

Updated: Oct 5, 2026

One-step Negative Chromatographic Purification of Helicobacter pylori Neutrophil-activating Protein Overexpressed in Escherichia coli in Batch Mode
10:44

One-step Negative Chromatographic Purification of Helicobacter pylori Neutrophil-activating Protein Overexpressed in Escherichia coli in Batch Mode

Published on: June 18, 2016

Characterizing antigenic determinants in Helicobacter pylori CagA capable of detecting serum antibodies in children

Min-Kyoung Shin1,2, Jin-Su Jun3, Soon-Wook Kwon1

  • 1Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Gyeongsangnam-do 52727, Korea.

Pathogens and Disease
|September 22, 2017
PubMed

Insights

This study identifies specific regions of the cytotoxin-associated gene A protein (CagA) that are useful for diagnosing Helicobacter pylori infection in children. These findings offer a promising new serological method for detecting H. pylori.

Area of Science:

  • Medical Microbiology
  • Immunology
  • Pediatric Gastroenterology

Background:

  • Helicobacter pylori infection is a common cause of gastric disorders.
  • Accurate diagnosis of H. pylori infection in children is crucial but challenging due to invasive methods.
  • Serological methods are preferred for pediatric diagnosis, necessitating the identification of suitable antigens.

Purpose of the Study:

  • To identify immunodominant regions of the cytotoxin-associated gene A protein (CagA) for H. pylori serodiagnosis in children.
  • To evaluate the diagnostic value of a partial recombinant CagA protein for detecting H. pylori infection.

Main Methods:

  • Subdividing CagA into 17 overlapping fragments for antigenic determinant analysis.
  • Immunoblot analysis using pooled serum from children with and without gastric symptoms.
  • Production of a partial recombinant CagA protein (683-749 amino acids) for serological testing.

Main Results:

  • Serum IgG reactivities were significantly higher (threefold) in children with gastric symptoms compared to those without.
  • Higher serum IgG reactivities correlated with stronger urease activity in gastric biopsies.
  • Identified specific epitope regions within CagA (683-749 amino acids) showing significant antigenicity.

Conclusions:

  • A partial recombinant CagA protein containing identified epitope regions is a valuable candidate antigen for H. pylori serodiagnosis in children.
  • This approach offers a non-invasive and potentially more accurate method for diagnosing H. pylori infection in pediatric populations.

Keywords:
ELISAHelicobacter pylori; CagAchildrenepitopeurease activity

More Related Videos

Rapid Detection of Helicobacter pylori Virulence and Typing Using Quantum Dot Labeling Technology05:13

Rapid Detection of Helicobacter pylori Virulence and Typing Using Quantum Dot Labeling Technology

Published on: June 13, 2025

Rapid Detection of Fecal Antigen of Helicobacter pylori Infection Based on Double Antibody Sandwich Detection Technology03:33

Rapid Detection of Fecal Antigen of Helicobacter pylori Infection Based on Double Antibody Sandwich Detection Technology

Published on: May 23, 2025

Related Concept Videos

Antigens Involved in Adaptive Immunity01:26

Antigens Involved in Adaptive Immunity

An antigen is any substance the immune system identifies as foreign and potentially harmful to the body, prompting an immune response. Antigens have two functional properties: immunogenicity and reactivity. Immunogenicity is the ability of an antigen to stimulate a specific immune response. At the same time, reactivity describes the antigen's ability to react with the cells and antibodies produced in response to it.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Peptic Ulcer Disease III: Clinical Manifestations and Diagnostic Studies01:28

Peptic Ulcer Disease III: Clinical Manifestations and Diagnostic Studies

Peptic ulcer disease (PUD) presents with diverse symptoms depending on the location and severity of the ulcer. Clinical manifestations of peptic ulcer include dull pain and a burning sensation in the mid-epigastric region.
Few clinical manifestations differentiate gastric ulcers from duodenal ulcers. Distinctions in the location, timing, and pain relief are crucial for healthcare providers in differentiating between gastric and duodenal ulcers during clinical assessments.
Determinants of Bacterial Pathogenicity and Virulence01:20

Determinants of Bacterial Pathogenicity and Virulence

Pathogenic bacteria employ a variety of strategies to establish infections, including the secretion of extracellular enzymes that act as potent virulence factors. These enzymes facilitate bacterial colonization of host tissues and help evade immune surveillance. By targeting structural components of host tissues and interfering with immune mechanisms, these enzymes play a pivotal role in disease progression.Extracellular Enzymes Facilitating Tissue Invasion: Several bacterial pathogens secrete...
Gastritis II: Pathophysiology01:26

Gastritis II: Pathophysiology

The pathophysiology of gastritis begins with the colonization of the stomach lining by Helicobacter pylori (H. pylori). This bacterium spreads mainly via the oral-oral route through saliva or shared utensils, and can also be transmitted in overcrowded or unhygienic environments through contaminated water, despite its brief survival outside the body.ColonizationOnce ingested, H. pylori enters the stomach and begins colonization by navigating through the mucus layer lining the stomach wall. It...