No, this test detects Shiga toxin 1 and 2, even from non-O157 strains! Studies show an EIA for EHEC Shiga Toxin detects approximately 40% more EHEC O157-H7 than conventional culture, and it is also able to detect an additional 20% more Shiga-toxin producing E.coli that are non-O157-H7.

Yes, CDC Guidelines recommend Shigan toxin testing be performed on growth from broth culture because this method is more sensitive and specific than direct testing of stool. In addition, because the amount of free fecal Shiga toxin in stools is often low, EIA testing of broth enrichments from stools is recommended rather than direct testing.

It is known that culture will miss ALL non-O157 strains. It is also known that the sensitivity for culture detecting the O-157 strains is low. The documented infection rate is about 50:50 for O157 strains vs. non-O157 strains. You should be testing for both!

1. https://www.nphl.org/documents/ShigaToxinTestingRecommendations.pdf
2. CDC Recommendations and Reports MMWR October 16, 2009 / 58(RR12);1-14
3. Morbidity and Mortality Weekly Report. 2013;62(50):1029-1031

Premier^™ EHEC – 87427

Broth Enrichment – 87015