Pathogenicity of a bovine attaching effacing Escherichia coli isolate lacking Shiga-like toxins.
Escherichia coli isolate 7996-90, obtained from a calf with diarrhea, had negative results of tests for K-88, K-99, 987P, F41, CS31A, F1845, F165 or E. coli adherence factor adhesins and had negative results of tests for the toxins heat-labile, heat-stable A, heat-stable B, Shiga-like toxin (SLT)-I or SLT-II. Strain 7996-90 had localized adherence to HEp-2 cells, caused actin rearrangement in host cells to which it adhered, hybridized with the eaeA probe, and produced the 94-kd outer membrane protein associated with attaching effacing lesions. This isolate caused attaching effacing lesions in Caco-2 cell polar monolayers, rabbit intestinal loops, and the intestines of gnotobiotic pigs. The isolate belongs to serotype O26: NM and is considered a class-II attaching effacing enteropathogenic E coli. Until recent addition of more sensitive assays at veterinary diagnostic laboratories, isolates such as 7996-90 were not readily recognized as pathogens because they failed to fit into the enterohemorrhagic E coli group, members of which, be definition, produce SLT. The assays described can facilitate diagnosis of attaching effacing E coli infection when histologic evaluation is hampered by autolysis.
Veterinary Medical Diagnostic Laboratory, College of Veterinary Medicine, University of Missouri, Columbia 65211.
J
J
Fischer
C
C
Maddox
R
R
Moxley
D
D
Kinden
M
M
Miller
D000818:Animals; D001422:Bacterial Adhesion; D001427:Bacterial Toxins / Q000032:analysis / Q000235:genetics*; D002417:Cattle; D002418:Cattle Diseases; D002432:Cecum / Q000382:microbiology / Q000648:ultrastructure; D002460:Cell Line; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary; D004848:Epithelium / Q000382:microbiology / Q000648:ultrastructure; D004926:Escherichia coli / Q000302:isolation & purification / Q000472:pathogenicity* / Q000502:physiology; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D006801:Humans; D007422:Intestines / Q000382:microbiology; D008854:Microscopy, Electron; D011817:Rabbits; D015183:Restriction Mapping; D012703:Serotyping; D013552:Swine; D014774:Virulence / Q000235:genetics
D001427:Bacterial Toxins