RESEARCH ON ADHESION STRUCTURES AND VIRUL ENCE FACTORS IN ESCHERICHIA-COLI THAT ARE ADHESIVE TO CALF INTESTINAL VILLI, BUT THAT DO NOT PRODUCE ADHESINS F5 (K99), F-17 AND F111 IN-VITRO

Research on adhesion structures and virulence factors in E. coil that are adhesive to calf intestinal villi, but that do not produce adhesin s F5 (K99), F17 and F111 in vitro; A total of 139 E. coli strains were studied that were isolated from feaces of carves suffering from diarr hea. The isolates adhered to calf enterocytes but did not produce adhe sins F5 (K99), F17 and F111 in vitro. In 75% of these strains we ident ified adhesins (20K or C1209), or genes of which the gene products are involved in adhesion (F17,papA). Enterotoxin or cytoxin coding genes (STaP, LT-II, CNF) were observed in 29% of the isolates. Among these, 23 strains are papA + CNF1+, that could represent a new pathotype. Of these 3F- strains 74% expressed surface protein CS31A, but its rol in pathogenesis needs to be determined. Finally, none of the 139 strains is recognised by probes specific for SLT, LTp or STb, nor by probe cor responding to intimin Eae or adhesins F4 or F6.