New Study Allegedly Links Food Animals to Human UTIs

A recent study has reportedly suggested that some food animals, and
chickens in particular, are “likely” reservoirs for the extraintestinal pathogenic
E. coli (ExPEC) implicated in community-acquired urinary tract infections
(UTIs) among humans. Catherine Racicot Bergeron, et al., “Chicken Reservoirs
for Extraintestinal Pathogenic Escherichia coli in Humans, Canada,” Emerging
Infectious Diseases, March 2012. According to the study, Canadian researchers
compared ExPEC isolates from slaughtered chicken, pork and beef “with the
preexisting geographically and temporally matched collection of isolates from
humans with UTIs,” in order to determine “whether transmission was human
to human through food or whether an animal source was involved.”

“In the case of human-to-human transmission through food, E. coli strains
from humans would be introduced during the meat preparation process by food handlers. In the case of an animal source, E. coli would derive from the cecal content of the animal itself, and contamination would occur during the
slaughtering process,” stated the study authors, who tested both retail meat
and food animals in abattoirs. Their results evidently revealed that ExPEC
isolates taken from slaughtered animals “can belong to the same clonal
groups” as those taken from humans with UTIs. They also found that, in the
case of retail meats, “beef and pork isolates are much less likely than chicken
isolates to be clonally related to isolates from humans with UTIs.”

While noting that “epidemiological data, such as diet or other exposures, were
not available for the humans with UTIs,” the authors have interpreted the close
genetic similarities between some isolates as confirmation of their hypothesis
“that potential ExPEC transmission from food animal sources is likely to be
implicated in human infections and that chicken is a major reservoir. The
possibility that ExPEC causing UTIs and other extraintestinal infections in
humans could originate from a food animal reservoir raises public health
concern. New interventions may be needed to reduce the level of contamination
and risk for transmission,” they concluded.