EFFECT OF INHIBITORS OF HELA-CELL STRUCTURES AND FUNCTIONS ON ESHERICHIA-COLI HB101 (PRI203) ENTRY PROCESS

We investigated the effect of some eucaryotic cytoplasmic structure an d function inhibitors on the entry into HeLa cells of the Escherichia coli HB101 K12 strain, harbouring the recombinant plasmid pRI203, in w hich is cloned a 3.2 Kb chromosomal fragment of Yersinia pseudotubercu losis. Substances impairing microfilament structures and functions (cy tochalasin B and trifluoroperazine) significantly reduced invasion abi lity whereas microtubule organization inhibitors (colchicine and vinbl astine) were ineffective. Data obtained with a lipophilic weak base (m ethylamine), which raises the pH of intracellular vesicles, demonstrat ed that, in entry pathway of E. coli HB101 (pRI203), endosome acidific ation is not required. Host cell energy has been shown to contribute t o bacterial internalization since the presence of oxidative phosphoryl ation and glycolysis inhibitors (sodium azide, 2-dinitrophenol and 2-d eoxy-D-glucose) during the invasion process, affected bacterial entry.