The University of Georgia College of Veterinary Medicine

eorgia Veterinary Scholars Program

GVSP Summer 2008 Scholars

Georgia Veterinary Scholar	Faculty Mentor

Samantha Shields University of Illinois-Champaign-Urbana Class of 2011	Dr. John Maurer

Vertical Transmission: Major Contributor to Chicken Carcass Contamination with Salmonella

Shields, Samantha*. Gokal, Payal; Flemister, Akeem; Zamperini, Kate; Mathis, Demetrius; Hofacre, Charles; Maurer, John; Department of Population Health, University of Georgia, 953 College Station Rd., Athens, GA 30602

Despite vast improvements in sanitation practices among poultry processing plants, persistence of Salmonella within the human food chain remains a major threat to public health. In order to effectively reduce Salmonella carcass contamination levels, we need to decrease the number of contaminated animals entering the processing plant. This will require a better understanding of how the organism is transmitted and at what points it is introduced into the production system. Within the poultry integrator, Salmonella can be transmitted
to an animal in one of two ways: from the immediate environment or through vertical transmission from parent to progeny. To investigate which mode contributes to carcass contamination, we examined several possible
points of introduction within a poultry integrator. Salmonella was isolated from the poultry environment, of broiler breeder and broiler farms, and poultry carcasses. Broiler farms were paired to broiler breeder farms
that stocked progeny for these farms. Polymerase Chain Reaction (PCR) and Pulsed-field Gel Electrophoresis (PFGE) were used to determine Salmonella serovars and strains. We found, with a few exceptions, the same S. Enteritidis and S. Kentucky strains on broiler chicken carcasses as those found in the
poultry environment of both broiler and broiler breeder farms, suggesting that vertical transmission plays a major role in carcass contamination. By identifying the production level at which Salmonella strains are introduced, effective implementation of intervention strategies can catalyze major strides in reducing broiler carcass contamination with Salmonella.

Research Support: CDC PulseNet and PCR Protocols