The Analysis Of The DNA Fingerprinting Of Intestinal Flora In UC And Other Intestinal Diseases

Background and Objective:Ulcerative colitis(UC)is a kind of non-specificity chronic enteric inflammatory diseases , which is one of inflammatory bowel disease.The incidence of UC is becoming gradually ascendant recent years, but the pathogenesy of UC is still not entirely understood , now genetic susceptibility, mucosal immunity and intestinal microecology and their interactions are considered to be involved in the pathogenesis of UC.Nowadays the prevailing theory explaining the development of UC is that the adaptive immune system is hyper-responsive to the commensal intestinal microflora in genetically susceptible individuals. Recently with the development of mircoecology, there are increasingly interests on intestinal flora and pathogenesis of UC.Microorganism plays an important role in pathogenesis of UC, but no specific pathogenic microorganism has been found related to UC so far. The number of enterobacteria species could be cultured in vitro only accounts for small percent of the total number of enterobacteria species. DNA fingerprinting based on PCR technology could be used to analyze the makeup of intestinal flora. Enterobacterial Repetitive Intergenic Consensus (ERIC) sequence is a kind of reverse and repeated sequence mostly located in the enterobacteria genome that is 126 bp in size .It is located in noncoding transcribed regions of the chromosome, in either orientation with respect to transcription , which has highly conservation and chromosomal localization has species specificity. The technology of ERIC-PCR use highly conserved sequence to design primer, ERIC-PCR generates multiple distinct amplification products of sizes ranging from approximately 50 to 3000 bp. Each kind of bacteria has special electrophoretic bands with different number and the main band could be appeared stably and repeatedly. The unique location of ERIC elements in bacterial genomes allows discrimination at genus, species, and strain levels based on the electrophoretic pattern amplification products. So DNA fingerprintings of UC patients, acute gastroenteritis, IBS patients and healthy persons were set up based on ERIC-PCR technology,and the total difference of their intestinal flora was analysised.Methods: The fecal samples of 19 UC ,11 acute gastroenteritis, 6 IBS and eleven healthy controls were collected, DNA fingerprinting was setup by using of ERIC(enter bacterial repetitive mtergenic consensus )-PCR technology,and the total difference of their intestinal flora was analyzed.Results: The DNA fingerprintings of the four groups were identified, and a significant differences was noticed between them. More bands in IBS,acute gastroenteritis and healthy groups, but fewer in the UC cases. Strikingly, one single predminant band ( 0.7kb) of DNA fingerprinting was noticed in 18 UC samples; two predominant bands (1.1kb and 0.8kb) were noticed in acute gastroenteritis samples; the healthy control and IBS group did not show predominant bands.Conclusion: Compared with the variety of intestinal flora of IBS,acute gastroenteritis and healthy groups, UC patients have less predominant species of bacterial flora. Either UC or acute gastroenteritis holds different predominant flora, UC seems to have a single predominant intestinal bacterial flora which might associtated with the pathogenisis of UC.