Screening of food raw materials for the presence of Shiga toxin-producing Escherichia coli O91:H21.
OBJECTIVE
To provide information on the prevalence and detection, in foods, of Shiga toxin-producing Escherichia coli (STEC) O91:H21.


RESULTS
Seven hundred fifteen minced beef meats and 205 raw milk samples were analysed by stx-specific PCR-ELISA. Samples positive for stx were subsequently tested for the presence of wzy-O91, fliC-H21 and the adhesin-encoding gene saa. For minced meat, 16 (2.2%) and 11 (1.5%) samples were found positive for (stx, wzy-O91, fliC-H21) and (stx, wzy-O91, fliC-H21, saa) combinations, respectively. For raw milk, seven (3.4%) samples were found positive for the (stx, wzy-O91, fliC-H21) combination but none of these contained saa. Two STEC O91:H21 saa-positive strains and three STEC O91 H21- and saa-negative strains were isolated by colony hybridization.


CONCLUSIONS
A low prevalence of potentially pathogenic STEC O91:H21 in food products was found using a combination of PCR assays targeting stx, wzy-O91, fliC-H21 and saa.


CONCLUSIONS
The PCR-based approach described here represents a valuable method for rapid screening of food samples contaminated by STEC O91:H21.
Madic
J
J
Agence Française de Sécurité Sanitaire des Aliments, Laboratoire d'Etudes et de Recherches sur la Qualité des Aliments et les Procédés agroalimentaires, Maisons-Alfort, France.
Lecureuil
C
C
Dilasser
F
F
Derzelle
S
S
Jamet
E
E
Fach
P
P
Auvray
F
F
D018829:Adhesins, Bacterial / Q000235:genetics; D000818:Animals; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay; D029968:Escherichia coli Proteins / Q000235:genetics; D005408:Flagellin; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D008461:Meat Products / Q000382:microbiology*; D008892:Milk / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D022621:Shiga Toxin / Q000096:biosynthesis* / Q000235:genetics; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification*
D018829:Adhesins, Bacterial; D029968:Escherichia coli Proteins; C516095:FliC protein, E coli; C439650:SAA protein, E coli; D005408:Flagellin; D022621:Shiga Toxin