Determination of Helicobacter pylori CagA EPIYA motifs and their association with clarithromycin resistance, gastropathology and clinical outcome

Tyrosine phosphorylation of CagA in Helicobacter pylori (H. pylori) occurs at the EPIYA motif region, a five aminoacid sequence (Glu-Pro-Ile-Tyr-Ala) that is present in variable numbers in the C-terminal EPIYA repeat region of the CagA protein. The aim of the study was to identify the 3? variable regions of the cagA gene of the H.pylori CagA EPIYA motifs in H.pylori strains and correlate with histopathological findings in patients? biopsies and also identify the relationship between EPIYA motifs and clarithromycin resistance. A total of 124 patients with dispepsia referred to upper endoscopy were included. H.pylori strains? cagA status was established. H.pylori cagA positive PCR products ranging 370-570 bp were amplified. PCR products purified by QIAquick PCR kit and sent to Macrogen for sequencing. Anti-H.pylori IgG and CagA IgG antibodies were determined by ELISA tests. Eighty-nine of 124 patients (71.8%) were H.pylori infection positive by at least two positivity of RUT, histopathology and culture. Sixty-two patients (50%) were positive by culture. Among H.pylori-culture positive patients; 30 (48.4%) were cagA positive, 32 (51.6%) were cagA negative. Among the 30 cagA positive strains; 21 (70%) had EPIYA-ABC, seven (23.3%) had EPIYA-ABCC and strains from two patients (6.7%) had both EPIYA-ABC and -ABCC. In 89 H.pylori positive patients; 77 (86.5%) were anti-H.pylori IgG, 14 (46.6%) were anti-CagAIgG positive. As a conclusion, cagA positive H.pylori strains were related to inflammation of pits (active inflammation) in antrum and corpus and atrophy in corpus. The correlation could not be found between EPIYA motifs and histopathology and clarithromycin resistance.