Development of bioluminescent Salmonella strains for use in food safety.
BACKGROUND
Salmonella can reside in healthy animals without the manifestation of any adverse effects on the carrier. If raw products of animal origin are not handled properly during processing or cooked to a proper temperature during preparation, salmonellosis can occur. In this research, we developed bioluminescent Salmonella strains that can be used for real-time monitoring of the pathogen's growth on food products. To accomplish this, twelve Salmonella strains from the broiler production continuum were transformed with the broad host range plasmid pAKlux1, and a chicken skin attachment model was developed.


RESULTS
Salmonella strains carrying pAKlux1 constitutively expressed the luxCDABE operon and were therefore detectable using bioluminescence. Strains were characterized in terms of bioluminescence properties and plasmid stability. To assess the usefulness of bioluminescent Salmonella strains in food safety studies, we developed an attachment model using chicken skin. The effect of washing on attachment of Salmonella strains to chicken skin was tested using bioluminescent strains, which revealed the attachment properties of each strain.


CONCLUSIONS
This study demonstrated that bioluminescence is a sensitive and effective tool to detect Salmonella on food products in real-time. Bioluminescence imaging is a promising technology that can be utilized to evaluate new food safety measures for reducing Salmonella contamination on food products.
Karsi
Attila
A
Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, P,O, Box 6100, Mississippi State, MS 39762-6100, USA. karsi@cvm.msstate.edu
Howe
Kevin
K
Kirkpatrick
Tasha B
TB
Wills
Robert
R
Bailey
R Hartford
RH
Lawrence
Mark L
ML
D000818:Animals; D002645:Chickens; D005506:Food Contamination / Q000517:prevention & control; D005516:Food Microbiology; D007091:Image Processing, Computer-Assisted; D049449:Luminescence; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D011202:Poultry Products / Q000382:microbiology*; D012449:Safety; D012475:Salmonella / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*
D008164:Luminescent Proteins