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ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Food and Feed Safety Research » Research » Publications at this Location » Publication #314518
Title: Investigation into possible differences in Salmonella prevalence in the peripheral lymph nodes of cattle derived from distinct production systems and of different breed types

Author
item Brown, Tyson
item Edrington, Thomas
item LONERAGAN, GUY - Texas Tech University
item HANSON, DEVIN - Texas Tech University
item MALIN, KATILYN - Texas Tech University
item ISON, JOSHUA - Texas A&M University
item Nisbet, David

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/8/2015
Publication Date: 11/1/2015
Publication URL: http://handle.nal.usda.gov/10113/5232623
Citation: Brown, T.R., Edrington, T.S., Loneragan, G.H., Hanson, D.L., Malin, K., Ison, J.J., Nisbet, D.J. 2015. Investigation into possible differences in Salmonella prevalence in the peripheral lymph nodes of cattle derived from distinct production systems and of different breed types. Journal of Food Protection. 78:2081-2084.

Interpretive Summary: Cattle may contain the bacteria Salmonella that can make people sick. Peripheral lymph nodes in these cattle have been shown to contain Salmonella. Pre-harvest interventions are needed to control Salmonella in cattle; however, not much is known about what causes Salmonella to spread from the gastrointestinal tract to peripheral lymph nodes. This research was conducted to specifically evaluate possible breed differences between fed Holstein cattle and their native counterparts. Results indicate that the differences observed between cull and fed cattle are not a breed effect and likely a function of age, immune function, or other factors prior to harvest. Future research is needed to examine these other factors that may influence Salmonella in cattle lymph nodes.

Technical Abstract: Previous research demonstrated significant variation in the prevalence of Salmonella in peripheral lymph nodes (PLNs) of feedlot and cull cattle with greater prevalence in feedlot cattle. Therefore, we performed a series of experiments to investigate if these differences in Salmonella prevalence in PLNs are due to or influenced by breed. Of the 467 Holstein and 462 native PLNs collected, 62.1% of Holstein and 59.7% of native samples harbored Salmonella (P > 0.05; qualitative culture) with 51.2 and 48.9% of samples containing quantifiable concentrations (P > 0.05), respectively. The concentration of Salmonella within the PLN followed a decreasing trend over the collection period (May-October); averaging 1.3 and 1.4 CFU log10/g lymph node for Holstein and native samples, respectively (P > 0.05). In the second experiment, we compared 100% Brahman cattle to their native beef counterparts, as we hypothesized that Brahman cattle’s resistance to insects may reduce Salmonella transmission via biting insects. 42 Brahman and 31 native cattle PLNs were collected and 100 and 97% contained quantifiable concentrations (> 0.1 log10 CFU/g) of Salmonella (P > 0.05), respectively. The concentration of Salmonella within the PLN averaged 3.0 CFU log10/g for Brahman and 2.9 CFU log10/g for native samples (P > 0.05). Using qualitative culture, we recovered Salmonella from 100% of PLNs from Brahman and 97% of native samples (P > 0.05). Results of this research indicate that the differences observed between cull and fed cattle are not a breed effect and likely a function of age, immune function, or other factors yet to be identified. Understanding which cattle are more likely to harbor Salmonella within PLNs will aid in targeting both pre- and post-harvest intervention strategies.