Identification of the virulence factor Cag A gene of Helicobacter pylori isolated from patients samples

G. Renuga^*1, A. Babu Thandapani¹ and Amba Bhavani^2
1Department of Biotechnology, Ultra College of Pharmacy, Madurai, Tamil Nadu, India.               
²Department of Microbiology, Ultra Best Dental Science College, Madurai, Tamil Nadu, India.   

A B S T R A C T
Helicobacter pylori is the human pathogen responsible for the development of gastritis, 15% of the patients may further progress to more severe conditions, peptic ulcer disease and gastric cancer. In fact, depending on the socioeconomic status of the country, the prevalence of infection varies from 40 to over 80% of the population, with higher rates for developing countries. Bacterial virulence factors are essential players in modulating the immune response involved in the initiation of carcinogenesis in the stomach. Helicobacter pylori is the most important carcinogen for gastric adenocarcinom in host genetic factors contribute to the regulation of the inflammatory response and to the aggravation of mucosal damage. A total of 25 samples were subjected to detect “Cag A “gene by PCR analysis. Genomic DNA was isolated from all collected saliva samples by the CTAB. PCR was carried out with specific primers 20 base oligonucleotide primers designated 16S rRNA-F (5’-TAA GAG ATC AGC CTA TGT CC-3’) and R (5’-TCC CAC GCT TTA AGC GCA AT-3’). PCR amplification was performed in thermo cycler to ensure full amplification at 40 cycles and PCR products were analyzed by 2% agarose gel electrophoresis. Out of 25 samples, 12 samples were infected with H.pylori as detected by Cag A gene as amplified 400bp fragment of H.pylori.  Identification of of Cag A in patients can be considered as a direct evidence of the presence of pathogen. PCR has been used to detect H.pylori “Cag A” gene in saliva samples of Indian patients.
Keywords: Cag A gene, Genomic DNA, Helicobacter pylori, Patient sample, PCR analysis