PFPC Daily - March 21, 2005

"... one has to conclude that fluoroquinolone use in poultry
production presents a long-term threat to people."

Drug-Resistant Bacteria on Poultry Products Differ by Brand

The John Hopkins University Gazette - March 21, 2005

By Donna Mennitto

The presence of drug-resistant pathogenic bacteria on uncooked
poultry products varies by commercial brand and is likely related to
antibiotic use in production, according to researchers at the Johns
Hopkins Bloomberg School of Public Health.

Their study is the first to directly compare bacterial contamination
of poultry products sold in U.S. supermarkets from food producers who
use antibiotics and from those who claim they do not. The study
focused on antibiotic resistance, specifically
fluoroquinolone-resistance in Campylobacter, a pathogen responsible
for 2.4 million cases of food-borne illness per year in the United
States, according to the Centers for Disease Control and Prevention.
The study is published online in the journal Environmental Health
Perspectives.

"Our use of medically important classes of antibiotics in food-animal
production creates a significant public health concern," said the
study's lead author, Lance Price, a doctoral candidate and fellow at
the school's Center for a Livable Future. "Companies that use
antibiotics foster the development of drug-resistant bacteria which
can spread to the human population. Claims have been made that using
antibiotics increases food safety by reducing pathogens on the meat.
Interestingly, in addition to the results regarding
fluoroquinolone-resistant Campylobacter, we also found that brands
that do not use any antibiotics during production were no more likely
to contain Campylobacter than those that do. In fact, the only brand
with a significantly lower rate of Campylobacter contamination was
actually an antibiotic-free brand."

Price said that previous epidemiological studies have indicated that
fresh poultry products are a major source of Campylobacter infections
in humans. Exposure can occur from undercooked products or through
cross-contamination during food preparation, when raw poultry is
handled in the kitchen. The danger of infection is heightened when
this pathogen is resistant to antibiotics. Not only can the bacteria
itself cause illnesses such as diarrhea in humans, but
fluoroquinolones are some of the most important drugs used to treat a
variety of infections, including those caused by Campylobacter. The
widespread presence of this drug-resistant form of the bacteria makes
the antibiotic less effective in human medicine. Especially
vulnerable are the very young, the elderly and people whose immune
systems are compromised.

In 2000, the Food and Drug Administration proposed to withdraw
approval of fluoroquinolone drugs for use in poultry production. That
effort has since been stalled by legal objections from Bayer, one of
the pharmaceutical companies manufacturing the drug. In the meantime,
two major U.S. poultry producers, Tyson Food and Perdue Farms,
announced separately in 2002 that they would immediately stop using
fluoroquinolones to treat their flocks.

One year after the Tyson and Perdue announcements, Price and his team
began a survey of Campylobacter isolates on uncooked chicken products
from Tyson and Perdue and from two other producers, Eberly and Bell &
Evans, who claim their production methods are completely
antibiotic-free. Using both standard isolation methods and new
methods modified to enhance detection of fluoroquinolone-resistant
Campylobacter, they compared retail products purchased at grocery
stores in Baltimore. A high percentage of the products from the two
conventional brands were contaminated with fluoroquinolone-resistant
Campylobacter (96 percent from Tyson and 43 percent from Perdue)
while significantly lower proportions of 'antibiotic-free' products
were contaminated with fluoroquinolone-resistant Campylobacter (5
percent from Eberly and 13 percent from Bell & Evans).

"These results suggest that fluoroquinolone-resistance may persist in
the food supply for a substantial period of time even after
antibiotic use is discontinued," Price said. "Assuming that what we
are observing are lingering resistant strains rather than the result
of continued drug use, then one has to conclude that fluoroquinolone
use in poultry production presents a long-term threat to people."

The study, co-authored by E. Johnson, R. Vailes and E. Silbergeld,
was supported by the Johns Hopkins Center for a Livable Future and by
the Heinz Family Foundation.

SOURCE:
http://www.jhu.edu/~gazette/2005/21mar05/21chick.html