RAPID detection and quantification of E. coli O157/O26/O111 in minced beef by real-time PCR.
OBJECTIVE
To develop a real-time PCR detection procedure for Escherichia coli O111, O26 and O157 from minced meat.


RESULTS
Strains (n = 8) of each of E. coli O26, E. coli O111 and E. coli O157 were inoculated at ca 10-20 CFU g(-1) into minced retail meat and enriched for 6 h at 41.5 degrees C as follows: E. coli O26 in tryptone soya broth (TSB) supplemented with cefixime (50 microg l(-1)), vancomycin (40 mg l(-1)) and potassium tellurite (2.5 mg l(-1)); E. coli O111 in TSB supplemented with cefixime (50 microg l(-1)) and vancomycin (40 mg l(-1)); E. coli O157 in E. coli broth supplemented with novobiocin (20 mg l(-1)). DNA was extracted from the enriched cultures, and detected and quantified by real-time PCR using verotoxin (vt1 and vt2) and serogroup (O157 per gene; O26 fliC-fliA genes and O111 wzy gene) specific primers.


CONCLUSIONS
The methods outlined were found to be sensitive and specific for the routine detection of E. coli O111, O26 and O157 in minced beef.


CONCLUSIONS
The enrichment, isolation and detection procedures used in this study provide a rapid routine-based molecular method for the detection and differentiation of E. coli O26, O111 and O157 from minced meat.
O'Hanlon
K A
KA
The National Food Centre, Teagasc, Ashtown, Dublin, Ireland.
Catarame
T M G
TM
Duffy
G
G
Blair
I S
IS
McDowell
D A
DA
D003470:Culture Media; D015342:DNA Probes / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification*; D019453:Escherichia coli O157 / Q000235:genetics / Q000302:isolation & purification; D005516:Food Microbiology; D005798:Genes, Bacterial / Q000235:genetics; D008460:Meat / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods*
D003470:Culture Media; D015342:DNA Probes; D004269:DNA, Bacterial