Biological activity of Helicobacter pylori oncoprotein CagA is determined by the diversity in the EPIYA motif sites which may be repeated within the variable region. CagA proteins possessing greater number of EPIYA repeats are more likely to be associated with gastric cancer development. In the present study, types of the H. pylori CagA EPIYA motifs were studied in H. pylori isolates from individual patients.

In 14 H. pylori- positive patients, four single colonies were isolated from the primary H. pylori culture plates. In each isolate, cagA status, genotype of variable 3’-region and patterns of EPIYA motifs were determined by PCR amplification using appropriate primers.

In 11/14 patients, all four isolates were cag A+. Out of 11 patients, EPIYA motif pattern of ABC was observed in all isolates of one patient and ABCC was observed in seven patients. Mixed pattern of EPIYA motifs were observed in 3/11 patients; in patient one, three isolates were ABCC and one isolate was ABC, in patient 2, three isolates were ABC and one BC, in patient 3, three isolates were ABC and one AB. In 2/14 patients, two isolates were cagA+ with ABC pattern and 2 cagA-. in 1/14 patient, two isolates were cagA+ with AB and ABC patterns and two isolates were cagA-.

Results of this study showed that H. pylori isolates with different EPIYA motif types could be simultaneously present in the same stomach. Considering the key role of cagA gene in H. pylori pathogenesis, further studies is need to elucidate any correlation between cagA genetic diversity and clinical outcomes.