THE EFFECT OF IRON ON THE INVASIVENESS OF ESCHERICHIA-COLI CARRYING THE INV GENE OF YERSINIA-PSEUDOTUBERCULOSIS

The effect of growth in iron-excess or iron-limitation conditions on t he invasiveness for HeLa cells of Escherichia coil HB101 carrying plas mid pRI203 which bears the invasion gene of Yersinia pseudotuberculosi s was examined. Iron-limitation reduced adhesion and the number of org anisms internalised by HeLa cells by about 100-fold. The reduced adhes ion of iron-starved bacteria correlated with reduced hydrophobicity an d the reduced invasiveness appeared to depend on the plasmid copy numb er, which was 3.5-fold less than in bacteria grown in iron excess.