Analysis of the Genome Structure of the Nonpathogenic Probiotic Escherichia coli Strain Nissle 1917

作者：Lubomir Grozdanov, Carsten Raasch, Jürgen P. Schulze, U. Sonnenborn, Gerhard Gottschalk, Jörg Hacker, Ulrich Dobrindt · 发表于：Journal of Bacteriology · 年份：2004 · DOI：10.1128/jb.186.16.5432-5441.2004 · 被引用次数：373 · 研究领域：Escherichia coli research studies、Salmonella and Campylobacter epidemiology、Bacterial Genetics and Biotechnology

Nonpathogenic Escherichia coli strain Nissle 1917 (O6:K5:H1) is used as a probiotic agent in medicine, mainly for the treatment of various gastroenterological diseases. To gain insight on the genetic level into its properties of colonization and commensalism, this strain's genome structure has been analyzed by three approaches: (i) sequence context screening of tRNA genes as a potential indication of chromosomal integration of horizontally acquired DNA, (ii) sequence analysis of 280 kb of genomic islands (GEIs) coding for important fitness factors, and (iii) comparison of Nissle 1917 genome content with that of other E. coli strains by DNA-DNA hybridization. PCR-based screening of 324 nonpathogenic and pathogenic E. coli isolates of different origins revealed that some chromosomal regions are frequently detectable in nonpathogenic E. coli and also among extraintestinal and intestinal pathogenic strains. Many known fitness factor determinants of strain Nissle 1917 are localized on four GEIs which have been partially sequenced and analyzed. Comparison of these data with the available knowledge of the genome structure of E. coli K-12 strain MG1655 and of uropathogenic E. coli O6 strains CFT073 and 536 revealed structural similarities on the genomic level, especially between the E. coli O6 strains. The lack of defined virulence factors (i.e., alpha-hemolysin, P-fimbrial adhesins, and the semirough lipopolysaccharide phenotype) combined with the expression of fitness factors such ...