PLASMID-MEDIATED INVASIVENESS OF SHIGELLA-LIKE ESCHERICHIA-COLI

  • 1 January 1982
    • journal article
    • research article
    • Vol. A133  (3) , 351-355
Abstract
Invasive E. coli is a Shigella-like microorganism which caused a dysenteric syndrome through invasion of the human colonic epithelium. Representative strains of different serotypes were studied in order to determine whether plasmids are involved in their virulence. All invasive E. coli strains, irrespective of serotype, were found to harbor a large plasmid of .apprx. 140 megadaltons. Spontaneous variants of serotypes 0143 and 0124 had lost this plasmid and had become avirulent, i.e., could neither penetrate into human cervical carcinoma HeLa cells nor produce a keratoconjunctivitis in guinea-pigs. pWR110, a Tn5-labeled virulnece plasmid of S. flexneri, was transferred into these avirulent variants, thus restoring their virulence and demonstrating that S. flexneri and invasive E. coli share a common extrachromosomal control of their ability to penetrate into cells.