Improvement of biomolecular methods for the identification and typing of Escherichia coli O157:H7 isolated from raw meat.
The aim of the study was to evaluate the sensitivity of two m-PCR methods for the quantitative determination of E. coli O157:H7 in foodstuffs. Genomic serotyping was carried out on bacterial cultures, and the necessary time was optimized to increase the resolution of the method. Subsequently, artificial contamination trials using meat were conducted to assess method accuracy in foodstuffs and pursue the genetic typing of pathogens. Measurement thresholds were shown to range between 10(5) and 10(6) CFU/mL, but were reduced by four logarithmic cycles in 80% of samples. Relative to the meat contamination trials, serotypes were identified after 24 hours, corresponding to 10 CFU/mL inoculum, with higher rates seen when m-TSB was used for enrichment. Inoculated samples were found to contain three virulence factors (hlyA, eaeA, and stx1).
Paris
A
A
Department of Animal Health, University of Parma, Parma, Italy.
Bonardi
S
S
Bacci
C
C
Boni
E
E
Salmi
F
F
Bassi
L
L
Brindani
F
F
D000818:Animals; D002417:Cattle; D019453:Escherichia coli O157 / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D005516:Food Microbiology; D015964:Gene Expression Regulation, Bacterial; D023281:Genomics; D008460:Meat / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D012703:Serotyping / Q000379:methods; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
D037521:Virulence Factors
J Clin Microbiol. 1998 Feb;36(2):598-602
9466788
J Med Microbiol. 2001 Feb;50(2):135-142
11211220
J Clin Microbiol. 1995 Aug;33(8):2188-91
7559976
J Infect Dis. 1987 Mar;155(3):377-89
3543152
Lett Appl Microbiol. 2006 Feb;42(2):102-8
16441372
J Clin Microbiol. 2002 Oct;40(10):3613-9
12354854
J Vet Med B Infect Dis Vet Public Health. 2006 Sep;53(7):299-305
16930272