Bacteria in Chickens

[Guest guest]

I know that we all know this - but it is good to see the research

proving it.

 

Jo

 

Poultry Consumption, Handling Are Risk Factors For Antibiotic

Resistance In Humans

 

Antibiotic use as a livestock growth promoter increases the risk of

human antibiotic resistance, a Marshfield Clinic researcher and his

colleagues have found.

 

Results of the nearly $1.4 million three-year study, funded by the

Centers for Disease Control and Prevention, Atlanta, Georgia, are in

the November 1 issue of The Journal of Infectious Diseases.

 

Edward Belongia, M.D., Marshfield Clinic Research Foundation,

Marshfield, Wis., and his colleagues examined poultry exposure as a

risk factor for antibiotic resistance in Enterococcus faecium, a gut

bacterium that is increasingly the cause of infections in hospitals.

The investigation team focused on use of a growth-promoting

antibiotic, called virginiamycin, in poultry.

 

Virginiamycin is closely related to quinupristin-dalfopristin, an

antibiotic licensed to treat patients with serious, antibiotic-

resistant infections. The drug is prescribed under the brand name

Synercid. According to Belongia, " There is a relative lack of data on

the impact of antibiotic use in livestock and its relationship to

antibiotic resistance in humans, but there is a fair amount of

indirect evidence suggesting that antibiotic use could pose a risk to

human health. "

 

" We've known for a long time that resistant bacteria can be found on

retail poultry products, but our study is one of the first to show an

association between human carriage of antibiotic resistance genes and

eating poultry or handling raw poultry.

 

" These results indicate that virginiamycin use in poultry leads to

transfer of antibiotic resistance genes to human gut bacteria through

the food supply and they provide additional evidence that use of

growth promoters in animals may have long-term consequences for human

health. The Food and Drug Administration (FDA) can use this

information to improve its risk assessment procedures. "

 

The importance of this issue was illustrated by a recent FDA

Veterinary Medicine Advisory Committee meeting about an application

to license a broad spectrum antibiotic, called cefquinome, for use in

cattle. Belongia spoke at the hearings, representing the Infectious

Diseases Society of America.

 

" There was a great deal of concern that this antibiotic could promote

resistance to cephalosporin drugs that are essential for many

patients with serious or life-threatening infections, " Belongia

said, " and at the end of the day the FDA committee recommended

against the drug. Our study focused on a different drug in a

different type of animal, but this is a timely example of the

controversy regarding the appropriate use of antibiotics in food-

producing animals.

 

" We need to have drugs to treat sick animals, " he added, " but we

should not be using antibiotics to promote growth. "

 

Working with Belongia, as principal investigator, were members of the

Marshfield Enterococcal Study Group - Amy L. Kieke, Ph.D., Mark A.

Borchardt, Ph.D., Burney A. Kieke, Susan K. Spencer and Mary F.

Vandermause; and Minnesota Department of Health, St. Paul, Minnesota -

Kirk E. Smith and Selina L. Jawahir. Amy Kieke was the first author

on the published paper. Borchardt directed laboratory activities to

detect antibiotic resistance and resistance genes. Belongia and

colleagues posed the question: Does exposing poultry to virginiamycin

lead to Synercid-resistant E. faecium in humans?

 

They isolated E. faecium in stool samples from 105 newly-hospitalized

patients and 65 healthy vegetarians, as well as in 77 samples of

conventional retail poultry and 23 antibiotic-free poultry meat

samples.

 

After exposure to virginiamycin, E. faecium from conventional poultry

and from patients who consumed poultry became resistant to Synercid

more often than E. faecium from vegetarians or from antibiotic-free

poultry. Some of the resistance was attributed to a specific gene and

both the gene and resistance were associated with touching raw

poultry meat and frequent poultry consumption.

 

Laboratory tests showed the bacteria isolated from patients and

vegetarians had no pre-existing resistance to Synercid. Resistance

was rare among antibiotic-free poultry but a majority of bacterial

isolates from conventional poultry samples were resistant.

 

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http://www.journals.uchicago.edu/JID/journal/issues/v194n9/36242/brief

/36242.abstract.html

 

The Marshfield Clinic system provides patient care, research and

education with 41 locations in northern, central and western

Wisconsin, making it one of the largest comprehensive medical systems

in the United States.

 

Contact: Chris Schellpfeffer

Marshfield Clinic