Isolation of Shiga toxin-producing Escherichia coli O103 from sheep using automated immunomagnetic separation (AIMS) and AIMS-ELISA: sheep as the source of a clinical E. coli O103 case?
OBJECTIVE
To investigate whether a sheep flock was the original reservoir of a Shiga toxin-producing Escherichia coli (STEC) O103 strain causing a clinical human case and to compare the two diagnostic methods automated immunomagnetic separation (AIMS) and AIMS-ELISA.


RESULTS
AIMS detected Escherichia coli O103 in 36.5% of the samples and AIMS-ELISA detected E. coli O103 in 52.1% of the samples. Polymerase chain reaction detected stx1 and eae in three of 109 E. coli O103 isolates. Pulsed field gel electrophoresis showed that the sheep and human STEC O103 were characterized by distinctly different profiles.


CONCLUSIONS
The sheep flock was shown to carry STEC O103, although an association between the sheep flock and the clinical human case could neither be proven nor eliminated. Substantial agreement was found between AIMS and AIMS-ELISA, but AIMS-ELISA was less time consuming and resulted in a higher recovery of E. coli O103.


CONCLUSIONS
The study shows that sheep may be carriers of STEC that are associated with human disease and that the methods described can be used to increase the sensitivity of STEC detection.
Department of Pharmacology, Microbiology and Food Hygiene, The Norwegian School of Veterinary Science, Oslo, Norway.
A M
AM
Urdahl
K
K
Cudjoe
E
E
Wahl
E
E
Heir
Y
Y
Wasteson
D018829:Adhesins, Bacterial / Q000235:genetics; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000662:veterinary; D029968:Escherichia coli Proteins; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D007223:Infant; D016133:Polymerase Chain Reaction; D012756:Sheep; D012757:Sheep Diseases / Q000382:microbiology*; D022622:Shiga Toxin 1 / Q000235:genetics; D022603:Shiga Toxins / Q000096:biosynthesis* / Q000235:genetics
D018829:Adhesins, Bacterial; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022603:Shiga Toxins; C073819:eaeA protein, E coli