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  • Author or Editor: Rodney Moxley x
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Summary

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, heatstable 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.

Free access
in American Journal of Veterinary Research

Objective

To determine whether booster vaccination with a multivalent clostridial bacterin-toxoid would affect the sudden death syndrome (SDS) mortality rate among feedlot cattle.

Design

Field trial.

Animals

83,115 cattle at a Nebraska feedlot.

Procedure

Cattle arriving at the feedlot underwent routine processing according to established protocol. All cattle received a sequentially numbered ear tag and a 2-ml dose of a multivalent bacterin-toxoid designed to protect cattle against Clostridium chauvoei, C septicum, C novyi, C sordellii, and C perfringens types C and D. Approximately 90 days prior to slaughter, growth promotants were implanted in all cattle, and cattle were allocated to a treatment or control group on the basis of the last digits of their ear tag numbers. Cattle in the treatment group received a second 2-ml dose of clostridial bacterin-toxoid; control cattle did not.

Results

Significant differences between groups in regard to crude, feeding pen, or SDS mortality rates were not detected. Sudden death syndrome mortality rate across both groups was 0.24%. If the SDS mortality rate in midwestern feedlot cattle was reduced ≥ 40% by booster vaccination with a multivalent clostridial bacterin-toxoid, this experiment included enough animals to have a 90% probability of detecting that difference.

Clinical Implications

Booster vaccination with a multivalent clostridial bacterin-toxoid does not affect SDS mortality rate among feedlot cattle. (J Am Vet Med Assoc 1997,211:749–753)

Free access
in Journal of the American Veterinary Medical Association