CagA subtyping in Helicobacter pylori isolates from gastric cancer patients in an ethnic Kashmiri population

Microb Pathog. 2014 Jan:66:40-3. doi: 10.1016/j.micpath.2013.12.004. Epub 2014 Jan 9.

Abstract

The association between gastric cancer and Helicobacter pylori has been well established. Among H. pylori virulence genes the most important determinant is the cytotoxin associated antigen gene (cagA) which is characterized by the presence of repeated EPIYA motifs at the C terminus of the protein. From the alignment and number of these EPIYA motifs, two major types of CagA protein have been identified.

Aims: The aim of this study was to classify the CagA into eastern or western type and to determine the number and type of motifs present.

Methods: The CagA subtyping was done by PCR and multiplex PCR for eastern/western classification and determination of EPIYA motifs respectively.

Results: All the isolates studied were of the western type, with 70% of the isolates having more than one EPIYA-C motifs. No statistically significant association was found between the presence of CagA and more than one EPIYA-C motifs with the clinical outcome (differentiation status of the tumour).

Keywords: CagA protein; EPIYA motifs; Gastric cancer; Helicobacter pylori.

MeSH terms

  • Antigens, Bacterial / genetics*
  • Bacterial Proteins / genetics*
  • Bacterial Typing Techniques
  • DNA, Bacterial / genetics
  • Gastritis / ethnology
  • Gastritis / microbiology*
  • Genotype
  • Helicobacter Infections / ethnology
  • Helicobacter Infections / microbiology*
  • Helicobacter pylori / classification*
  • Helicobacter pylori / genetics
  • Helicobacter pylori / isolation & purification
  • Humans
  • India / epidemiology
  • Phenotype
  • Polymerase Chain Reaction
  • Stomach Neoplasms / ethnology
  • Stomach Neoplasms / microbiology*
  • Virulence Factors / genetics

Substances

  • Antigens, Bacterial
  • Bacterial Proteins
  • DNA, Bacterial
  • Virulence Factors
  • cagA protein, Helicobacter pylori