Immunodot detection of Escherichia coli heat-stable enterotoxin b by using enhanced chemiluminescence reaction.
An indirect immunodot assay with rabbit antibodies raised against purified heat-stable enterotoxin type b (STb) and with a Western blotting (immunoblotting) detection system (ECL; Amersham International plc, Amersham, United Kingdom) was developed for the detection of STb toxin. Culture supernatants of 62 Escherichia coli isolates from pigs with diarrhea were blotted onto nitrocellulose and incubated with anti-STb serum. The chemiluminescence produced by the action of horseradish peroxidase with luminol and H2O2 was recorded by exposure of X-ray film. Over 90% correlation was observed between the rat or pig intestinal ligated loop assay and a radioactive DNA probe and the ECL immunodot assay for the detection of STb. In addition, using this new and sensitive technique, we could detect STb in the feces of a newborn pig inoculated with an STb-producing E. coli strain. Detection of STb-producing E. coli in pigs with diarrhea will be greatly facilitated by the use of this convenient and rapid diagnostic assay.
Department of Pathology and Microbiology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Québec, Canada.
L A
LA
Lortie
J
J
Harel
J M
JM
Fairbrother
J D
JD
Dubreuil
D000818:Animals; D001427:Bacterial Toxins / Q000032:analysis*; D001681:Biological Assay; D003967:Diarrhea / Q000175:diagnosis; D004768:Enterotoxins / Q000032:analysis*; D004926:Escherichia coli / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000175:diagnosis; D029968:Escherichia coli Proteins; D005069:Evaluation Studies as Topic; D005243:Feces / Q000382:microbiology; D015151:Immunoblotting / Q000379:methods*; D008163:Luminescent Measurements; D051381:Rats; D013552:Swine
D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C034151:heat stable toxin (E coli)