1.PCR-based analysis of Helicobacter pylori virulent genotypes among dyspeptic patients from Chittagong, Bangladesh
Abdul Musaweer Habib ; Md. Jibran Alam ; Bashudev Rudra ; Dil Umme Salma Chowdhury ; Md Abdul Quader ; Mohammad Al-Forkan
Malaysian Journal of Microbiology 2017;13(1):xx-xx
Aims: Helicobacter pylori is a causative agent of gastroduodenal diseases in Bangladesh as well as throughout the
world. This study aimed to determine the H. pylori cagA, vacA and iceA virulent genotypes by PCR directly in gastric
biopsies from dyspeptic patients of Chittagong, Bangladesh and evaluating the association of these genotypes with
clinical manifestations.
Methodology and results: CLO (Campylobacter-Like Organism) test and Hp16s PCR (16S rRNA based H. pylori
specific PCR) was performed to confirm H. pylori infection. Among 111 patients, H. pylori infection was found in 60
patients by CLO test, while Hp16s PCR revealed that 54 patients were H. pylori positive. PCR amplification of the H.
pylori virulence genes was successful in 35 gastric biopsies amongst the 54 Hp16s PCR positive biopsies. The positive
rates for the cagA, vacAs1, vacAs2, vacAm1, vacAm2, iceA1, iceA2 genes were 34.3%, 71.4%, 8.6%, 62.9%, 28.6%,
20% and 11.4%, respectively. The allelic variant vacAs1m1 had a predominant percentage with 51.4%, followed by
vacAs1m2, vacAs2m2 and vacAs1m1m2 with 14.3%, 5.7% and 2.9%, respectively. Among the subtypes of vacAs1, only
s1a was detected in 54.3% of biopsies while none of the cases showed the s1b and s1c genotypes. However, there was
no statistically significant association (p>0.05) observed between the virulent genotypes and clinical conditions.
Conclusion, significance and impact of study: We found that cagA, vacAs1m1 and iceA1 were the most frequent H.
pylori genotypes in severe clinical outcomes of the infection. The data in this study would provide a basis for
understanding the diverse virulence pattern of this bacterium in Bangladeshi dyspeptic patients.
Helicobacter pylori