Molecular evidence of helicobacter species in human gastric biopsy specimens

ABSTRACT

The genus Helicobacter consists of 24 formally recognized species, 7 of which have been associated with human disease. The best studied of these is the gastric pathogen Helicobacter pylori. To identify different Helicobacter [H.] species as causative organisms gastritis. 35 patients undergoing upper gastrointestinal endoscopy were selected [21males and 14 females. Age ranged from [25-60 years]. Gastric biopsy specimens were subjected to rapid urease test [RUT], bacteriological identification by Gram stain, culture and molecular detection of Helicobacter by polymerase chain reaction [PCR]. Then species identification using restriction fragment length polymorphism [RFLP] technique. 14 Helicobacter were identified [12 H. pylori, 2H. non-pylori ] were positive by PCR. Gram negative spiral organisms were detected in 10 out of 14 cases that were positive by PCR [the gold standard method] with sensitivity of 71% and a specificity of 90% while culture was positive in 10/ 14 positive PCR cases with sensitivity [71%] and high specificity of [100%] [p <0.001] and 11 out of 14 are positive by RUT, and 2 out of 14 are H. non-pylori .It was concluded that PCR. RFLP are useful molecular techniques for rapid identification and differentiation of different Helicobacter species