With all of the stories about bacterial contamination of food, a
recent paper describes one possible way to reduce the
virulence–the ability to cause disease–of the bacterium
Escherichia coli. Farms are an obvious…input of E. coli–the
amount of feces that a single pig produces is staggering, never
mind a thousand pigs*. The concern is that E. coli from
agricultural settings can either serve as a genetic reservoir of
virulence (disease-causing) genes (and antibiotic resistance
genes too), or as a source of virulent E. coli strains, such as
E. coli O157:H7. What the authors of paper observed is that when
pig manure is stored, the frequency of virulence genes found in
E. coli decreases. Interestingly, this decrease stems from a
decrease in virulent strains and a loss of virulence genes in
one common genotype. The authors also incubated E. coli in
sterilized manure, and found that the strains without virulence
genes dominated after seven weeks. Mind you, this isn’t very
glamorous, but it could play a big role in