AIMS: The verotoxigenic Escherichia coli (VTEC) serotype most commonly associated with verotoxin (VT) production is O157:H7, but other serotypes have also been implicated in food-borne illness. These serotypes exhibit much greater genetic and biochemical diversity than E. coli O157:H7, making screening for all VTEC difficult. Here we describe development and testing of novel multi-analyte antibody-based dipstick methods for presumptive detection of VTEC cells and VTs, including non-O157 serotypes.
METHODS AND RESULTS: The dipsticks are formatted as paddle-style and lateral flow devices. Test materials included raw milk, minced beef, apple juice and salami, spiked with VTEC. Prototype paddle dipsticks gave 47 of 48 E. coli O157-positive samples correct, and, simultaneously, 27 of 31 O26-positive samples correct, across the four food types. Prototype lateral flow dipsticks gave 12 of 12 E. coli O157-positive milk samples correct and, simultaneously, 28 of 28 positive VT samples correct.
CONCLUSIONS: This work demonstrates that simple and rapid detection of more than one VTEC characteristic (toxin production and type, serogroup) is possible in a single dipstick test device, directly from a food enrichment culture.
SIGNIFICANCE AND IMPACT OF THE STUDY: The development of simple easy-to-use rapid methods for simultaneous detection and preliminary characterization of VTEC will enable the risk presented by all VTEC to be more thoroughly assessed (e.g. in surveillance studies, outbreak investigations).
|Number of pages||10|
|Journal||Journal of Applied Microbiology|
|Publication status||Published - 2003|
- Antibodies, Bacterial
- Bacterial Typing Techniques
- Cell Line
- Escherichia coli
- Escherichia coli O157
- Food Microbiology
- Reagent Strips
- Shiga Toxins
- Specimen Handling