Colorado State University Extension
SafeFood Rapid Response Network


SAFEFOOD NEWS - Fall 1997 - Vol 2 no 1

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At the Laboratory: E. Coli Genome Being Mapped

A team of 250 scientists, known as the E. coli Genome Project researchers and led by Dr. Frederick R. Blattner of the University of Wisconsin in Madison, have sequenced the genome of an E. coli strain called K-12. This strain, which is not known to cause disease, contains more than 4.6 million base pairs and 4,288 protein-coding genes, of which ". . . 38% have no attributed function."

Although the strain is not pathogenic, the researchers did find pathogenic (disease-causing) "immigrant" DNA in the K-12 strain, suggesting it ". . . has relics of a pathogenic past or, alternatively, is a pathogen waiting to happen."

According to Blattner, there are several important clinical implications in the completion of this monumental project. First, comparison of K-12 with pathogenic strains of E. coli such as the 0157:H7 strain the strain implicated in the recent hamburger patty recall will help researchers to identify pathogenic genes, and, down the line, develop drugs to help treat E. coli- associated food poisoning.

The E. coli K-12 sequence also represents a ". . . veritable database to be used in uncoding the human genome sequence," Blattner said. Comparisons between the human and E. coli genomes will provide a crucial starting point for scientists in the identification and understanding of disease-associated genes.

According to a Research News article in Science, the E. coli genome ". . . is neither the first nor the largest to be sequenced. But because of the rich history of the organism itself, it stands out among the dozen or so genomes now in the public record."

This information is expected to help pharmaceutical companies develop new antibiotics and vaccines, especially valuable commodities in light of reports of increasing bacterial resistance to available treatments.

Updated Monday, August 29, 2011