TY - JOUR
T1 - Validation of three rapid screening methods for detection of verotoxin-producing Escherichia coli in foods: interlaboratory study
AU - Capps, Katherine L
AU - McLaughlin, Emiline M
AU - Murray, Alistair W A
AU - Aldus, Clare F
AU - Wyatt, Gary M
AU - Peck, Michael W
AU - van Amerongen, Aart
AU - Ariëns, Renata M C
AU - Wichers, Jan H
AU - Baylis, Christopher L
AU - Wareing, David R A
AU - Bolton, Frederick J
PY - 2004/4/16
Y1 - 2004/4/16
N2 - An interlaboratory study was conducted for the validation of 3 methods for the detection of all verotoxin-producing Escherichia coli (VTEC) in foods. The methods were a multi-analyte 1-step lateral flow immunoassay (LFIA) for detection of E. coli O157 and verotoxin (VT); an enzyme-linked immunosorbent assay targeted against VT1, VT2, and VT2c (VT-ELISA); and a polymerase chain reaction (PCR) method for detection of VT genes (VT-PCR). Aliquots (25 g or 25 mL) of 4 food types (raw minced [ground] beef, unpasteurized milk, unpasteurized apple juice [cider], and salami) were individually inoculated with low numbers (<9 to 375 cells/25 g) of 6 test strains of E. coli (serogroups O26, O103, O111, O145, and O157) with differing VT-producing capabilities. Five replicates for each test strain and 5 uninoculated samples were prepared for each food type. Fourteen participating laboratories analyzed samples using the LFIA, 9 analyzed the samples by ELISA, and 9 by PCR. The LFIA for O157 and VT had a specificity (correct identification of negative samples) of 92 and 94%, respectively, and a sensitivity (correct identification of positive samples) of 94 and 55%, respectively. The VT-ELISA and VT-PCR had a specificity of 98 and 99%, respectively, and a sensitivity of 89 and 72%, respectively.
AB - An interlaboratory study was conducted for the validation of 3 methods for the detection of all verotoxin-producing Escherichia coli (VTEC) in foods. The methods were a multi-analyte 1-step lateral flow immunoassay (LFIA) for detection of E. coli O157 and verotoxin (VT); an enzyme-linked immunosorbent assay targeted against VT1, VT2, and VT2c (VT-ELISA); and a polymerase chain reaction (PCR) method for detection of VT genes (VT-PCR). Aliquots (25 g or 25 mL) of 4 food types (raw minced [ground] beef, unpasteurized milk, unpasteurized apple juice [cider], and salami) were individually inoculated with low numbers (<9 to 375 cells/25 g) of 6 test strains of E. coli (serogroups O26, O103, O111, O145, and O157) with differing VT-producing capabilities. Five replicates for each test strain and 5 uninoculated samples were prepared for each food type. Fourteen participating laboratories analyzed samples using the LFIA, 9 analyzed the samples by ELISA, and 9 by PCR. The LFIA for O157 and VT had a specificity (correct identification of negative samples) of 92 and 94%, respectively, and a sensitivity (correct identification of positive samples) of 94 and 55%, respectively. The VT-ELISA and VT-PCR had a specificity of 98 and 99%, respectively, and a sensitivity of 89 and 72%, respectively.
KW - Animals
KW - Beverages
KW - Colony Count, Microbial
KW - Enzyme-Linked Immunosorbent Assay
KW - Escherichia coli
KW - Escherichia coli O157
KW - Food Microbiology
KW - Immunoassay
KW - Malus
KW - Meat
KW - Milk
KW - Reproducibility of Results
KW - Reverse Transcriptase Polymerase Chain Reaction
KW - Shiga Toxins
U2 - 10.1093/jaoac/87.1.68
DO - 10.1093/jaoac/87.1.68
M3 - Article
C2 - 15084089
SN - 1060-3271
VL - 87
SP - 68
EP - 77
JO - Journal of AOAC International
JF - Journal of AOAC International
IS - 1
ER -