Molecular evidence of helicobacter species in human gastric biopsy specimens

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

Helicobacter pylori CagA genotype in patients with gastritis and peptic ulcer

H. pylori infection of the stomach is widespread and is considered to play a major role in the pathogenesis of gastric diseases such as peptic ulcer and adenocarcinoma. The virulence of this type of bacteria in gastroduodenal disease is related to virulence gene [cagA] present in some strains. The aim of this study was to investigate the presence of H. pylori cagA genotype and its association with clinical outcomes. H. pylori were isolated and rapid urease test was conducted from gastric biopsy specimens obtained from 93 patients [68 with gastritis and 25 with gastric ulcer]. The cagA genotype was detected by PCR. CagA genotype was present in 41% of the patients infected with H. pylori positive both by culture and rapid urease test. CagA genotype was correlated with the severity of gastritis [p=.017] and gastric ulcer [p=.047]. Dyspepsia patients should be tested for cagA status along with the tests for H. pylori status; and a positive cagA testing should be considered as an indication for eradication of treatment