Cattle have been implicated as carriers of the human pathogen Escherichia coli
O157:H7. Contamination of the beef supply by E. coli O157 can occur during harvest
and processing, causing costly recalls or human illness. Many interventions have been
applied in attempts to prevent contamination of carcasses in processing plants, such
as development of HACCP procedures, carcass washes, and steam pasteurization, but
contaminations still occur. Mechanisms that allow E. coli O157:H7 to thrive in cattle
at sporadic times and in such large numbers are poorly understood. Understanding
factors that stimulate E. coli O157 growth in cattle will aid in identifying effective interventions
that can be applied in feedlots and processing plants to reduce the numbers of
this pathogen.
E. coli O157 resides in the intestinal tracts of cattle. Mucin is a major component of
intestinal mucus and is composed of proteins, lipids, and carbohydrates, which many
bacteria can use as a source of food. The amount of mucin available in the intestinal
tract depends on the stimulation of intestinal mucus-producing cells (goblet cells),
which may be influenced by the animal’s diet, stress, and a variety of other factors. Our
objective in this experiment was to determine if mucin produced in the small or large
intestine could affect growth of E. coli O157:H7.
