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Serotypes and virulence factors of Shiga toxin‐producing Escherichia coli isolated from healthy Norwegian sheep
Author(s) -
Urdahl A.M.,
Beutin L.,
Skjerve E.,
Wasteson Y.
Publication year - 2002
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1046/j.1365-2672.2002.01787.x
Subject(s) - serotype , virulence , stx2 , biology , microbiology and biotechnology , escherichia coli , shiga toxin , polymerase chain reaction , toxin , shiga like toxin , vero cell , enterobacteriaceae , dna profiling , virology , gene , dna , genetics , virus
Aims: To characterize a number of Shiga toxin‐producing Escherichia coli (STEC) isolates from sheep and to discuss the potential of these isolates as human pathogens. Methods and Results: Twelve different O‐groups and seven different H‐types were identified by standard serotyping methods. The most common serotypes were O5:NM, O6:H10, O91:NM and O128:NM. Polymerase chain reaction (PCR) was used for the detection of virulence factor genes. Of 102 isolates, 86·3% carried stx 1 and 83% of these were also positive in the stx 1OX3 ‐specific PCR. stx 2 was carried by 55·9% of the isolates and 77·2% of these were also positive in the stx 2d ‐specific PCR. The Vero cell assay showed high toxin production in 70·6% of the isolates. None of the isolates carried eae . Conclusions: The study supports the animal–host relationship suggested in other studies with STEC serogroups O5, O91 and O128 strongly associated with sheep. Most sheep STEC carry stx 1OX3 (except O91) and the dominating stx 2 variant is stx 2d . One stx profile clearly dominates within a serotype. Significance and Impact of the Study: In spite of the predominance of certain sheep‐associated STEC, sheep cannot be excluded as carriers of human pathogenic STEC.