A Cross-Sectional Study on Molecular Detection of Helicobacter pylori cytotoxin-associated gene A and 16SrRNA Gene from Gastric Biopsy Specimens

Manjula A Vagarali; Sharada C Metgud; Hema Bannur; Suneel S Dodamani

doi:10.4103/jgid.jgid_60_20

A Cross-Sectional Study on Molecular Detection of Helicobacter pylori cytotoxin-associated gene A and 16SrRNA Gene from Gastric Biopsy Specimens

J Glob Infect Dis. 2021 Aug 31;13(3):120-125. doi: 10.4103/jgid.jgid_60_20. eCollection 2021 Jul-Sep.

Authors

Manjula A Vagarali¹, Sharada C Metgud¹, Hema Bannur², Suneel S Dodamani³

Affiliations

¹ Department of Microbiology, JNMC, KAHER, Belagavi, Karnataka, India.
² Department of Pathology, JNMC, KAHER, Belagavi, Karnataka, India.
³ Dr. Prabhakar Kore Basic Science Research Centre, Belagavi, Karnataka, India.

Abstract

Introduction: The aim of the study is relative proportion of cytotoxin-associated gene A (cagA) virulence marker in Helicobacter pylori isolates and gastric biopsy samples by polymerase chain reaction (PCR).

Methods: This cross-sectional study was conducted at a tertiary care hospital setting. Gastric biopsy tissues from 200 patients, suffering from upper gastrointestinal tract disorders, were examined for H. pylori infection using methods, such as hematoxylin and eosin (H and E) staining, 16S rRNA (Ribosomal ribonucleic acid), and cagA gene PCR. Chi-square and kappa statistics were used to find the association and agreement between the tests, respectively; P ≤ 0.05 was considered statistically significant. Screening tests' accuracy was calculated in terms of sensitivity and specificity along with positive and negative predictive values.

Results: Out of 200 patients, H. pylori was detected in 14.5%, 48.5%, and 31% patients by H and E staining, 16S rRNA, and cagA PCR, respectively. Sensitivity and specificity of cagA PCR as compared to H and E staining were 89.6% and 78.9%, respectively.

Conclusions: CagA detection directly from biopsy specimen by PCR can potentially and rapidly determine the patient's status, especially when at a higher risk of peptic ulcer.

Keywords: polymerase chain reaction; Culture; Helicobacter pylori; cytotoxin-associated gene A; diagnosis; gastric biopsy.