Comment from Walter Hill

Although broadening the scope of adulterant serotypes is a step in the right direction, I feel that relying on serotype, a feature that is only indirectly associated with a bacterial strain’s potential for virulence in humans is last century’s technology. While serotyping has served us well, now is the time to progress to looking directly at which virulence factors might be harbored by a given strain. While the eae and stx genes might not be the only requirements to cause disease in humans, they certainly play a role. It is not clear that the presence of these genes in the TOP SIX E. coli serogroups make strains more virulent than if they occur in other serogroups. Therefore, I would ask that FSIS consider investigating the impact on food safety of screening meat products for these genes and not limiting adulteration to the presence of now these seven (including O157) serogroups.