http://www.bsse.ethz.ch/ctsb/research/SystemsBiology/r_cdi

Bacterial Contact Dependent Inhibition

Contact-dependent growth inhibition (CDI) is a phenomenon in which one cell can inhibit the growth of another cell upon direct cell-to-cell contact. This system, originally described in 2005 in a rat fecal isolate of Escherichia coli (EC93), consists of an outer-membrane toxin protein (CdiA), its corresponding outer-membrane transporter (CdiB), and a cognate immunity (CdiI). Recently, CDI systems have been identified in various pathogens including uropathogenic E. coli (urinary tract infection), Yersinia pestis (plague), and Dickeya dadantii (plant soft-rot). However, unlike EC93, these systems are not constitutively expressed. Preliminary data suggests that inhibitory activity is controlled by as yet unknown environmental cues. Current work involves the study of CDI regulation with the goal of understanding the role it plays in cell-to-cell communication and competition.