“…It is well known that genes coding for different adhesins, resistance genes and the heat-labile as well as heat-stable enterotoxins of ETEC strains are localized on plasmids (Bertin, 1998;Gomez-Duarte et al, 1999;Mainil et al, 1998;Mazaitis et al, 1981). F17 fimbria determinants can be co-localized with genes coding for the cytotoxic necrotizing factor 2 on virulence plasmids of necrotoxigenic E. coli strains (Mainil et al, 2000).…”