[DNA fingerprinting of h. pylori isolates from Iranian patients by REP-PCR]

ABSTRACT

H. pylori has been implicated in peptic diseases, some with detrimental consequences such as ulcer or cancer. Since considerable genetic heterogeneity has been observed within H. pylori population worldwide, it appears an ideal achievement to recruit PCR-based methods and design genetic markers which recognize isolates from normal and symptomatic individuals. In this study 61 H. pylori isolates from dyspeptic patients were fingerprinted by REP-PCR. REP-PCR was performed on extracted DNAs of 61 H. pylori isolates from 39 normal, 18 ulcer and 4 cancer patients. Synthetic 18-nt primers, specific for interspersed repetitive elements in the bacterial genome, were recruited. PCR conditions were optimized and reproducibility of the reactions were confirmed. The size and number of PCR products were determined and DNA fingerprints of all isolates were analyzed by NTSYSpc programme, and dendrograms were generated. Results: Among 39 H. pylori isolates from normal patients 28 comprised a distinct cluster and 5 clustered along with isolates from ulcer patients. The remaining 6 isolates comprised a separate cluster distinct from other groups. Among 18 isolates from ulcer patients, 17 classified in a specific cluster, only one isolate was clustered along with isolates from normal patients. Isolates from cancer patients consisted a quite distinct cluster. In this study REP-PCR was used to show that majority of isolates from normal, ulcer, and cancer patients have distinct fingerprints which can be recruited for predicting the outcome of the infection with certain H. pylori isolates. It is concluded that REP-PCR is an effective and reproducible technique for fingerprinting H. pylori isolates from different human origins