[Comparison of diagnostic methods for Helicobacter pylori detection and identification of cagA gene in clinical...

Helicobacter pylori (H. pylori) is the principal cause of peptic ulcer disease and important risk factor in gastric cancer. Gastric mucosal biopsy specimens taken from 110 patients were examined by polymerase chain reaction (PCR), culture and urease test. The ureA gene was detected in 52 out of 110 examined samples. The cagA gene was detected in 35 (67.3%) out of these 52 specimens (ureA+). This gene was presented in all of patients with stomach ulcer, in 75.0% of patients with duodenitis, 69.6% of patients with duodenal ulcer and 58.3% of patients with gastritis. H. pylori was detected by culture in 24 (25.3%) out of 95 samples. These results were confirmed by PCR. H. pylori was detected additionally in 20 samples only by PCR. This bacterium was detected more frequently by PCR than by culture (46.3% vs 25.3%). Results obtained by using three methods: culture, urease test and PCR were concordant in 47.0% (39 out of 83 patients). In 16 (19.3%) cases H. pylori was detected by two methods: urease test and PCR. Infection was detected only by PCR in 3 (3.6%) cases and in 25 cases (30.1%) only by urease test.