| Sumario: | Background: Helicobacter pylori inhabit the gastric mucosa of humans and are associated with several gastrointestinal diseases which include gastric cancer, peptic ulcer, chronic gastritis and gastric mucosa-associated lymphoid tissue lymphoma. Helicobacter pylori exhibit a high degree of genetic variability and are associated with its epidemiological, pathological characteristics and dynamics of transmission. The objective of the study was to determine the prevalence and genetic heterogeneity of H. pylori isolated from endoscopic biopsy samples from a Chinese population. Methods: Gastric biopsy samples from 86 patients (males, 55; females, 35) who presented to the endoscopic section for various gastrointestinal abnormalities were collected. The samples were subjected to a real-time polymerase chain reaction (PCR) and microbial culture for the isolation of H. pylori. Further, the isolates were subjected to randomly amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism (RFLP) analysis. Results: Of the 86 gastric biopsy samples, 61 (70.9%) samples were positive for rapid urease test and 37 (43%) samples (28 from male and nine from female) grew H. pylori. Among the biopsy samples subjected to real-time PCR, 39 (45.3%) samples were found to be positive for H. pylori. The RAPD analysis yielded 15 different patterns (four to 17 different sized fragments per strain). The phylogenetic analysis of RAPD yielded 22 clusters at a similarity level ranging from 63% to 100%. RFLP analysis yielded nine different patterns (two to six different sized fragments per strain). Two major restriction patterns were identified, of which 14 (37.8%) strains forms the most common pattern (genotype I) followed by five (13.5%, genotype II) strains with an intra-strain similarity of 100%. Conclusions: The overall prevalence of H. pylori was 45.3%. Despite reports on the declining trend in the prevalence of H. pylori infections, our prevalence rate was still higher than those reported from other developed countries. However, further studies involving a large sample size and covering more regions of China is highly warranted.
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