title: Airborne soil particulates as vehicles for Salmonella contamination of tomatoes.
abstract: The presence of dust is ubiquitous in the produce growing environment and its deposition on edible crops could occur. The potential of wind-distributed soil particulate to serve as a vehicle for S. Newport transfer to tomato blossoms and consequently, to fruits, was explored. Blossoms were challenged with previously autoclaved soil containing S. Newport (9.39log CFU/g) by brushing and airborne transfer. One hundred percent of blossoms brushed with S. Newport-contaminated soil tested positive for presence of the pathogen one week after contact (P<0.0001). Compressed air was used to simulate wind currents and direct soil particulates towards blossoms. Airborne soil particulates resulted in contamination of 29% of the blossoms with S. Newport one week after contact. Biophotonic imaging of blossoms post-contact with bioluminescent S. Newport-contaminated airborne soil particulates revealed transfer of the pathogen on petal, stamen and pedicel structures. Both fruits and calyxes that developed from blossoms contaminated with airborne soil particulates were positive for presence of S. Newport in both fruit (66.6%) and calyx (77.7%). Presence of S. Newport in surface-sterilized fruit and calyx tissue tested indicated internalization of the pathogen. These results show that airborne soil particulates could serve as a vehicle for Salmonella. Hence, Salmonella contaminated dust and soil particulate dispersion could contribute to pathogen contamination of fruit, indicating an omnipresent yet relatively unexplored contamination route.
authors.affiliation: Department of Food Science and Technology, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
authors.forename: Govindaraj Dev
authors.initials: GD
authors.lastname: Kumar
authors.affiliation: Department of Food Science and Technology, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA. Electronic address: rowilli3@vt.edu.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Williams
authors.affiliation: Center for Molecular Medicine and Infectious Diseases, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA.
authors.forename: Hamzeh M
authors.initials: HM
authors.lastname: Al Qublan
authors.affiliation: Center for Molecular Medicine and Infectious Diseases, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA.
authors.forename: Nammalwar
authors.initials: N
authors.lastname: Sriranganathan
authors.affiliation: Department of Food Science and Technology, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
authors.forename: Renee R
authors.initials: RR
authors.lastname: Boyer
authors.affiliation: Department of Food Science and Technology, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Eifert
mesh_terms: D018556:Crops, Agricultural / Q000382:microbiology; D035264:Flowers / Q000382:microbiology*; D005506:Food Contamination / Q000032:analysis*; D005638:Fruit / Q000382:microbiology*; D018551:Solanum lycopersicum / Q000382:microbiology*; D052638:Particulate Matter / Q000032:analysis*; D012475:Salmonella / Q000302:isolation & purification*; D012987:Soil; D012988:Soil Microbiology
chemical_list: D052638:Particulate Matter; D012987:Soil
keywords: Bioluminescence; Salmonella; Soil particulate; Tomato