SOLUTIONS FOR THE FOOD SAFETY THREAT POSED BY SALMONELLA IN THE LYMPH NODES OF CATTLE PRESENTED FOR HARVEST

• Sponsoring Institution: Agricultural Research Service/USDA
• Project Status: ACTIVE
• Funding Source: USDA INHOUSE
• Reporting Frequency: Annual
• Accession No.: 0422761
• Project Start Date: Sep 1, 2011
• Project End Date: May 31, 2012
• Program Code: [(N/A)]- (N/A)

Project Director
HARHAY D M

Recipient Organization
AGRICULTURAL RESEARCH SERVICE
(N/A)
CLAY CENTER,NE 68933

Performing Department
(N/A)

Non Technical Summary
(N/A)

Animal Health Component

40%

Research Effort Categories

Basic

60%

Applied

40%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
712	3310	1040	100%

Knowledge Area
712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins;

Subject Of Investigation
3310 - Beef cattle, live animal;

Field Of Science
1040 - Molecular biology;

Keywords

salmonella

cattle

bovine

subiliac

lymph

node

usda-nifa-icgp-003445

program

111.c

Goals / Objectives
Bovine peripheral lymph nodes, including subiliac lymph nodes, have been identified as a potential source of Salmonella, when trim containing these nodes is incorporated into ground beef. In order to gain a better understanding of the potential risk to human health imposed by Salmonella harborage in subiliac lymph nodes of fed and cull cattle at harvest, it is important to characterize the variation in regional, seasonal, and animal-type burden of Salmonella in these tissues. In the proposed study, we will examine the biology, epidemiology and ecology of Salmonella in bovine lymph nodes. The information gathered in these studies will be used to explore candidate control strategies and identify those that are most successful and adoptable.

Project Methods
Lymph nodes will be collected from cattle at harvest (n=1,200). Lymph node samples will be trimmed, surface sterilized, enriched and analyzed for the presence of Salmonella. Salmonella will be enumerated from a subset (yet to be determined) of lymph node samples. Salmonella isolated will be characterized as to serotype and antimicrobial susceptibility phenotype. A subset of Salmonella isolated will undergo molecular characterization including pulsed field gel electrophoresis (PFGE) phenotyping, plasmid profiling, and genome/transcriptome sequencing.

Progress 10/01/11 to 09/30/12

Outputs
Progress Report Objectives (from AD-416): Bovine peripheral lymph nodes, including subiliac lymph nodes, have been identified as a potential source of Salmonella, when trim containing these nodes is incorporated into ground beef. In order to gain a better understanding of the potential risk to human health imposed by Salmonella harborage in subiliac lymph nodes of fed and cull cattle at harvest, it is important to characterize the variation in regional, seasonal, and animal-type burden of Salmonella in these tissues. In the proposed study, we will examine the biology, epidemiology and ecology of Salmonella in bovine lymph nodes. The information gathered in these studies will be used to explore candidate control strategies and identify those that are most successful and adoptable. Approach (from AD-416): Lymph nodes will be collected from cattle at harvest (n=1,200). Lymph node samples will be trimmed, surface sterilized, enriched and analyzed for the presence of Salmonella. Salmonella will be enumerated from a subset (yet to be determined) of lymph node samples. Salmonella isolated will be characterized as to serotype and antimicrobial susceptibility phenotype. A subset of Salmonella isolated will undergo molecular characterization including pulsed field gel electrophoresis (PFGE) phenotyping, plasmid profiling, and genome/transcriptome sequencing. The foodborne pathogen Salmonella has been detected in the lymph nodes of cattle at harvest. Fat trim containing lymph nodes is a common component of ground beef and has been identified as a source of Salmonella in this commodity. Thus the objective of this research is to characterize variation in regional, seasonal and animal-type burden of Salmonella in lymph nodes of cattle presented at harvest. Lymph nodes have been collected from 1,712 carcasses from abattoirs located in five regions of the U.S. Overall Salmonella prevalence has been 3.9%, with cull beef and dairy cattle lymph nodes at 2.2% positive and those of fed cattle at 4.6% positive.

Impacts
(N/A)

Publications