title: Development of a transdermal Salmonella challenge model in calves.
abstract: Recent investigations have found that Salmonella can be routinely recovered from peripheral lymph nodes (PLNs) of cattle presented for harvest. When contained within the PLNs, this foodborne pathogen is protected from currently used postharvest, inplant intervention strategies and, therefore, PLNs harboring Salmonella may be a potential contaminant of ground beef. The objective of this work was to develop a challenge model that effectively and repeatedly results in Salmonella -positive PLNs. A 10-lancet skin-allergy instrument was inoculated with Salmonella, and calves were inoculated intra- and/or transdermally by applying the device over various ventral regions of the skin. Salmonella was successfully and predictably recovered from regionspecific PLNs up to 8 days postchallenge. Furthermore, serotypes inoculated within specific regions were only recovered from the PLNs draining those regions. This model provides a method to predictably infect PLNs with Salmonella. Further, this model makes it possible to determine the duration of infection and to evaluate candidate interventions that may shorten the duration of infection.
authors.affiliation: Food and Feed Safety Research Unit, Southern Plains Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, 2881 F&B Road, College Station, Texas 77845, USA. tom.edrington@ars.usda.gov
authors.forename: T S
authors.initials: TS
authors.lastname: Edrington
authors.forename: G H
authors.initials: GH
authors.lastname: Loneragan
authors.forename: J
authors.initials: J
authors.lastname: Hill
authors.forename: K J
authors.initials: KJ
authors.lastname: Genovese
authors.forename: H
authors.initials: H
authors.lastname: He
authors.forename: T R
authors.initials: TR
authors.lastname: Callaway
authors.forename: R C
authors.initials: RC
authors.lastname: Anderson
authors.forename: D M
authors.initials: DM
authors.lastname: Brichta-Harhay
authors.forename: D J
authors.initials: DJ
authors.lastname: Nisbet
mesh_terms: D000818:Animals; D002417:Cattle / Q000382:microbiology*; D015169:Colony Count, Microbial; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control*; D005516:Food Microbiology; D006801:Humans; D008198:Lymph Nodes / Q000382:microbiology*; D008461:Meat Products / Q000382:microbiology*; D023421:Models, Animal; D015995:Prevalence; D012475:Salmonella / Q000302:isolation & purification*