Submitted to: Foodborne Pathogens and Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/2007
Publication Date: 6/1/2007
Citation: Jackson, C.R., Cray, P.J., Wineland, N., Tankson, J.D., Barrett, J.B., Douris, A., Pearson Gresham, C., Hall, M.C., Mcglinchey, B., Price, M.V. 2007. Introduction to usda vetnet: status of salmonella and campylobacter databases from 2004 through 2005. Foodborne Pathogens and Disease. 4(2):241-248.
Interpretive Summary: USDA VetNet commenced in March 2004 and a central computer server houses the USDA PFGE pattern libraries for comparison to human PulseNet PFGE patterns. The objectives of USDA VetNet are to determine PFGE patterns of Salmonella isolates submitted to NARMS, compare USDA VetNet and PulseNet PFGE patterns, and to use the comparative data for surveillance and investigation of food-borne illness outbreaks. To date, ARS staff has been trained at the CDC and certified, and standardized image acquisition and analysis protocols have been developed to analyze PFGE data obtained in the ARS laboratory. Nontyphoidal Salmonella serotypes from slaughter/processing collected as part of NARMS will be subjected to PFGE and PFGE patterns generated from those isolates will be completed first, before a retrospective analysis of older isolates begins. As the information generated from any monitoring system is descriptive, additional investigations and field studies will be initiated as a result of comparable patterns appearing in both animal and human isolates. The identification of similar PFGE patterns in both USDA VetNet and PulseNet will enable scientists to determine whether an outbreak is occurring and may establish possible source related information for further investigation.
Technical Abstract: USDA VetNet was established in 2003 and was modeled after PulseNet USA, the national molecular subtyping network for food borne disease surveillance. The objectives of USDA VetNet are to use pulsed-field gel electrophoresis (PFGE) to subtype zoonotic pathogens submitted to the animal arm of the National Antimicrobial Resistance Monitoring System (NARMS), compare USDA VetNet and PulseNet PFGE patterns, and to use the comparative data for surveillance and investigation of food borne illness outbreaks. Whereas PulseNet subtypes seven food borne disease-causing bacteria: Escherichia coli O157:H7, nontyphoidal Salmonella, Shigella, Listeria monocytogenes, Campylobacter, Yersinia pestis, and Vibrio cholerae, VetNet, at present, subtypes nontyphoidal Salmonella serotypes and Campylobacter from animals including diagnostic specimens, healthy farm animals, and carcasses of food-producing animals at slaughter. By the end of 2005, VetNet had three functioning databases including the NARMS Salmonella and Campylobacter databases. The Salmonella database contained 6,763 Salmonella isolates and 2,514 unique XbaI patterns, while the Campylobacter database contained 58 Campylobacter isolates and 53 unique SmaI patterns. Both databases contain the PFGE Tagged Image File Format (TIFF) images, demographic information, and the antimicrobial resistance profiles assigned by NARMS. In the future, veterinary laboratories will be invited to participate in VetNet. The establishment of USDA VetNet enhances the mission of the agriculture and public health communities in the surveillance and investigation of food borne illness outbreaks.