1. PAIGE L. STANLEY & TAYLOR A. WINSLOW
DEPARTMENT OF BIOLOGICAL & ENVIRONMENTAL SCIENCES
GEORGIA COLLEGE & STATE UNIVERSITY
MILLEDGEVILLE, GA 31061
THE PREVALENCE OF
PRESUMPTIVE PATHOGENS IN
COMMERCIAL AND FARMERS
MARKET MEATS

2. BACKGROUND
●Grain fed cattle are 6x more likely to test positive for
pathogenic E.coli 0157:H7 than non-grain fed cattle
(International Journal of Food Microbiology, 2009).
●Multidrug resistant isolates of Salmonella increased from
39% to 97% between 1979-1997 (New England Journal of
Medicine, 2001).

3. STATEMENT OF PURPOSE
● Studies have shown that in the U.S. there are 9.4
million episodes of foodborne illness and 55,961
hospitalizations each year (CDC, 2011).
● Studies have proven that high levels of antibiotic use
in the meat industry can lead to antibiotic resistance.
● No comparative studies have been done.
○ Is there a difference in occurrence of pathogens and their
antibiotic resistance between meat CAFO/corn fed meat and
farmers market meat?

4. ISOLATION & IDENTIFICATION METHODS*
*modified from USDA/FSIS and FDA/BAM Protocols
Proposed protocol for E.coli 0157:H7 :

5. MaconEatontonMilly
FCRCGW
BIG BOX FARMER’S MARKET
CT-SMAC CT-SMACECM ECM
E. COLI

6. CT-SMAC

7. MaconEatontonMilly
FCRCGW
BIG BOX FARMER’S MARKET
CT-SMAC CT-SMACTSAYE TSAYE
E. COLI
ECM ECMTESTING TESTING

8. Rapid 20E API Latex Agglutination
●Commercially available rapid
test for the identification of
Enterobacteriaceae.
●Blue latex particles coated with serum
against E.coli 0157 antigen.
●Positive results will cause agglutinate.
BIOCHEMISTRY & SEROLOGY

9. RESULTS OF E.COLI ISOLATION

10. RESULTS OF E.COLI ISOLATION

11. E. COLI ANTIBIOTIC SUSCEPTIBILITY
TE = Tetracycline
SXT = Trimethoprim/sulfmethoxazole
C = Chloramphenicol
S = Streptomycin

12. ISOLATION & IDENTIFICATION METHODS*
*modified from USDA/FSIS and FDA/BAM Protocols
Proposed protocol for Salmonella :

13. MaconEatonton
BIG BOX FARMER’S MARKET
RV RV
SALMONELLA
UPB UPBHC HCMilly
FCRCGW

14. HardyCHROMTM SALMONELLA

15. MaconEatontonMilly
FCRCGW
RV RVUPB UPBHC HC
BIG BOX FARMER’S MARKET
TESTING TESTING
SALMONELLA

16. IDENTIFICATION OF SALMONELLA
Gram Stain API Oxidase Latex
Agglutinati
on
TSI LIA
Eatonton 1B ( - ) Salmonella ( - ) ( + ) Pink Purple
Eatonton 2B ( - ) Salmonella ( - ) ( + ) Pink Purple
Eatonton 3B ( - ) Salmonella ( - ) ( + ) Pink Purple
+ Control ( - ) Salmonella ( - ) ( + ) Pink Purple

17. SALMONELLA ANTIBIOTIC SUSCEPTIBILITY
Locations TE SXT C S
Eatonton 1B 19 22 22 16
Eatonton 2B 19 22 22 14
Eatonton 3B 19 22 24 16
TE = Tetracycline
SXT = Trimethoprim/sulfmethoxazole
C = Chloramphenicol
S = Streptomycin
+ Control 18.5 21 22 12.5

18. DISCUSSION
● Two separate “big box” locations yielded:
○a single pathogenic E.coli 0157:H7 isolate.
○multiple Salmonella isolates.
● No presumptive pathogens were isolated from
farmers’ market samples.
● There was no significant antibiotic resistance
observed with either microorganism.

19. CONCLUSION
Even though we isolated some pathogens from big
box locations, the sample size for this study is not
large enough to indicate any significant difference.
While encouraging, this preliminary study would
need to be expanded to yield any significant
conclusion regarding the prevalence of pathogens in
commercial meats.

20. ACKNOWLEDGEMENTS
●Jyoti Lama - Graduate Student at GCSU
●Sergio Patitucci - Lab Coordinator
●Dr. Indiren Pillay’s Lab

21. REFERENCES
●David, White, Shaohua Zhao, and Tobert Sudler. “The Isolation of Antibiotic-
Resistant Salmonella from Retail Ground Meats.” The New England Journal of
Medicine 345 (2001): 1147-1154. Web. 26 Feb 2015.
●De Boer, E., J.T.M. Zwartkruis-Nahuis, and B. Wit. “Prevalence of Methicillin-
resistant Staphyococcus Aureus in Meat.” International Journal of Food
Microbiology 134 (2009):52-56. Web. 26 Feb 2015.
●Nguyen, Minh Chau Phuc, Paul-Louis Woerther, Mathilde Bouvet, Antoince
Andremont, Roland Leclercq, and Annie Caru. “Escherichia Coli as Reservoir
for Macrolide Resistance Genes.” Emerging Infectious Diseases 15.10
(2009):1648-1650. Centers for Disease Control and Prevention. 10 Mar.2015.
●Scallan, Elaine, Robert Hoekstra, and Frederick Angulo. “Foodborne Illness
Acquired in the United States- Major Pathogens.” Emerging Infectious
Diseases 17.1 (2011): 7-16 Centers for Disease Control and Prevention. Web. 26
Feb 2015
●Zelman, Robin. “Effects of Drug Concentration on Persistance in Escherichia
Coli.” Brown University- Ecology and Evolutionary Biology (2009). Web. 10
Mar. 2015.