E. coli O157:H7

Background:  E. coli O157:H7 is a recognized foodborne pathogen found in raw beef and more recently in produce.  It can cause serious and sometimes fatal illness at a very low infection dose (as few as 10 organisms).  The organism is often difficult to detect with traditional culture methods, especially where low levels of the target must be isolated from high levels of competing background flora.

The BAX System uses DNA-based technology to provide next-day results that are reliable and reproducible, allowing food producers and processors to quickly and accurately release safe products to the market.



Turn Around Time

Sample Required

Type of Test

Reportable Units

Detection Limit

Related Resources

AOAC 031002 BAX Real-Time PCR  ISO Accredited

BAX System

1 Business Day

25g or 65g or 375 g or Swab

Qualitative Pathogen Analysis

Negative or Positive per 25g or 65g or 375g or swab analyzed

One Viable Cell per 25 or 65g or 375g or swab analyzed

Link FDA Bad Bug Book Version 1 – Escherichia coli O157:H7 enterohemorrhagic (EHEC)

PDF FDA Bad Bug Book Version 2 – Enterohemorrhagic Escherichia coli (EHEC)

PDF FDA Bad Bug Book Versin 2 – Pathogenic Escherichia coli Group

Analysis Description:  This is a Quantitative analysis, this test will detect if only one E. coli O157:H7 cell is present, therefore resulting in a Negative or Positive result.  This assay does not tell you how much of the pathogen is present.

Standard sample sizes are one swab, 25g, 65g or 375g.  Representative sample portions are collected from sample submitted, mixed with highly selective enrichment media and incubated at 42°C for 8 to 12 hours minimum (depending on sample size).  After incubation, cells from the sample enrichment are broken open to expose their DNA, which, if the target E. coli O157:H7 DNA is present, will be copied thousands of times, allowing for detection via the BAX Real-Time PCR E. coli O157:H7 assay.

E. coli O157:H7 results are typically reported by (MT): 6 am Tue thru Fri; 7 am on Sat; 2 pm on Sun; 10 am on holidays.

Customers desiring cultural confirmation of positive pathogen enrichments must request so within 24 hours of MBL reporting the positive pathogen result.