ENTEROPATHOGENIC ESCHERICHIA-COLI MARKEDLY DECREASES THE RESTING MEMBRANE-POTENTIAL OF CACO-2 AND HELA HUMAN EPITHELIAL-CELLS

It is presumed. but not proven, that enteropathogenic Escherichia coli (EPEC) causes secretory diarrhea by altering ion transport in enteroc ytes. In this study we used the whole-cell, current clamp variant of t he patch clamp technique to demonstrate that EPEC infection of HeLa an d Caco-2 human epithelial cells reduces cell resting membrane potentia l. The observed reduction of resting membrane potential in Beta cells results from EPEC-mediated signal transduction to the host cell brit i s not dependent upon EPEC-mediated elevation of levels of intracellula r fi ee calcium, These findings indicate that EPEC can directly alter the relative distribution of ions across epithelial host cell membrane s. This may be relevant to the etiology of diarrhea caused by EPEC inf ection.