Clustering distribution of the specific fragment R049 of uropathogeulc Escherichia coil / 中华微生物学和免疫学杂志

ABSTRACT

Objective To study the distribution of the specific fragment R049 of uropathogenic E. coli(UPEC) 132 in UPEC and fecal E. coli strains. Methods The specific fragment R049 was amplified by PCR from 20 UPEC strains and 40 fecal E. coli strains, and 5 genes encoding virulence factors (papC, fimH, hly, aer, cnf1) were detected from fragment R049 positive strains. Pulse field gel electronphoresis (PFGE) was applied for isolating the Xba Ⅰ restriction fragments of the genomes of fragment R049 positive strains, and then Southern blot was applied for analyzing the distribution features of the positive hybridization bands by digoxin-labeled R049 ORF probe. Results The specific fragment R049 was amplified from 8 of 20 UPEC strains (40%) and 3 of 40 fecal E. coli strains (7.5%), and statistics analysis showed significant difference (P<0.01). The specific fragment 11049 was closely related with 5 virulence factors of UPEC in the fragment R049 positive strains. Southern blot showed the sizes of positive bands were 150 kb, 15 kb and 240 kb in 3 fecal E. coli strains, 350 kb in 6 of 8 UPEC strains, and 280 kb and 25 kb in the rest two UPEC strains. Conclusion The specific fragment R049 of UPEC132 possessed the feature of clustering distribu-tion in domestic isolated UPEC strains.