Evaluation of repetitive sequence-based genomic fingerprinting for molecular classification and identification of vibrio species / 대한내과학회지

BACKGROUND: The aims of this study were to compare the suitability of repetitive-PCR genomic fingerprinting procedures to investigate genetic relatedness of the genus Vibrio and its applicability for the molecular identification of Vibrio vulnificus. METHODS: Forty-eight Vibrio strains were included for this study. REP-, ERIC-, BOX- and SERE-PCR were compared with 13 members of the genus Vibrio. RESULTS: REP-, BOX- and SERE-PCR showed V. vulnificus strains could not be separated well from other Vibrio species. However, approximately 320 bp of highly discriminatory specific fragments was recovered from V. vulnificus strains by ERIC-PCR. CONCLUSIONS: ERIC-PCR could be used as rapid classification and identification methods of V. vulnificus from other members of the genus Vibrio.

High Prevalence of Multiple Strain Colonization of Helicobacter pylori in Korean Patients: DNA Diversity Among Clinical Isolates from the Gastric Corpus, Antrum and Duodenum

BACKGROUND: The aims of our study were to determine the correlation of the strain variation and degree of homogeneity of infecting Helicobacter pylori (H. pylori) with their disease outcomes, and the relevance of duodenal H. pylori expression of cagA and/or vacA gene to the development of duodenal ulcer in Korean patients. METHODS: One hundred and twenty bacterial colonies isolated from different anatomical sites of the stomach and duodenum were used. The study population was consisted of 40 Korean patients, 21 with duodenal ulcer, 7 with gastric ulcer, 3 with combined gastric and duodenal ulcer, and 9 with chronic gastritis. Genomic characteristics of each strain were analyzed by random amplified polymorphic DNA (RAPD) fingerprinting. The cagA and vacA genes were detected by polymerase chain reaction (PCR). RESULTS: PCR-based RAPD was proved to be a reliable method for the discrimination of individual bacterial genomic characteristics. Genomic fingerprinting showed a varying degree of inter- and intra-patient variation. Thirteen patients (32.5%) were colonized by a single strain throughout the corpus, antrum and duodenum, whereas the other 27 (67.5%) harbored multiple H. pylori strains. Thirty-six isolates (90.0%) each from the corpus and antrum, and 34 (85.0%) from the duodenum, expressed the cagA gene. The prevalence of duodenal H. pylori expression of the cagA gene was not different between patients with chronic gastritis and those with duodenal ulcer. All isolates were positive for both genes vacA s1 and vacA s1a. CONCLUSION: These results suggested that many of the H. pylori-infected Korean patients were actually colonized with mixed populations of different H. pylori strains and that the prevalence of duodenal H. pylori expression of the cagA and/or vacA gene was not correlated with the development of duodenal ulcer in Korean patients.

Profile of Virulence Genes and Rep-PCR Genomic Fingerprinting on Escherichia coli Strains Isolated from Patients with Urinary Tract Infection

The profile of virulence genes and repetitive element sequence-based PCR (rep-PCR) genomic fingerprinting were determined on Escherichia coli strains isolated from patients with urinary tract infection to investigate genetic relatedness and its identification. Thirty nine strains of E. coli were examined genotypically by using the multiplex polymerase chain reaction for the presence of five urovirulence genes; pyelonephritis-associated pili (pap), S. fimbriae (sfa), afimbrial adhesin (afa), cytotoxic necrotizing factor (cnf ), and a-hemolysin (hly). As a result, genotype pap+sfa-afa-cnf -hly- was the most dominant (14 strains: 36%). But no urovirulence-genes were detected in 12 strains (31%). On the basis of rep-PCR, the dendrograms generated from REP-PCR and ERIC-PCR revealed that uropathogenic E. coli strains were clustered into non-uropathogenic E. coli ATCC 43894 O157:H7 with the degree of similarity 37% and 44%, respectively. On the contrary, BOX-PCR results showed that uropathogenic E. coli strains differed from non-uropathogenic E. coli ATCC 43894 O157:H7 with the degree of similarity 37%. According to these findings, REP-PCR and ERIC-PCR were unable to discriminate reliably uropathogenic E. coli from non-uropathogenic E. coli. However, BOX-PCR provided an effective mean of differentiating E. coli strains between uropathogenic and non-uropathogenic.