E. coli Fingerprint Solves Cookie Dough Mystery

A genomic fingerprinting approach was used to identify the strain of the Escherichia coli O157:H7, which has been incriminated in the raw cookie dough scare in the United States. The E. coli O157:H7 is a strain not previously associated with eating raw cookie dough, but can be toxic to the kidney and in the worst cases, fatal.

The U.S. Centers for Disease Control and Prevention (CDC; Atlanta, GA, USA), the state health departments, federal regulatory partners, and many companies have been working together in the ongoing investigation to identify the E. coli strain responsible for the outbreak.

The CDC used a long polymerase chain reaction (PCR)-amplified ribosomal DNA (rDNA) for PCR restriction fragment length polymorphism (PCR-RFLP)- and Rep-PCR-based approach to recognize the culprit E.coli strain. Long PCR can be used to amplify fragments of bacterial ribosomal operons. Rep-PCR is a genomic fingerprinting method based on the use of DNA primers corresponding to naturally occurring interspersed repetitive elements in bacteria, such as the REP, ERIC, and BOX elements, and the PCR reaction (rep-PCR).

As of June 22, 2009, 70 persons infected with an E. coli O157:H7 with the DNA fingerprint of the strain have been reported from 30 states in the USA.

Related Links:
U.S. Centers for Disease Control and Prevention