Determining the DNA Fingerprinting Profiles of Salmonella spp. Isolated from Raw Poultry Meats and Human Clinical Samples from the Same Geographic Area Using Pulsed Field Gel Electrophoresis.

Abstract

Foods of animal origin, such as poultry, eggs, and pork, are recognized sources of infection with Salmonella , but determining the proportion of foodborne infections resulting from different food sources has been challenging. In the current study, 141 Salmonella strains isolated from poultry products (n=1322) purchased over a period of one year from retail stores across Seattle, Washington, were subtyped by Pulsed Field Gel Electrophoresis (PFGE) using restriction enzyme Xba I. The objectives of the study were: I) to analyze the longitudinal distribution of Salmonella PFGE profiles throughout the sampling period and their clonality within and between different poultry processing establishments; II) to determine the association between PFGE profiles of Salmonella isolated from locally distributed poultry products to those of clinical isolates submitted to the Washington State Department of Health Laboratories (WA-DOH); and III) to compare the PFGE profiles of Salmonella isolated from the National Antimicrobial Resistance Monitoring System (NARMS) retail meats program. Over the sampling period of one year, multiple indistinguishable PFGE patterns were found across multiple poultry processing establishments. There were 12 out of 30 unique PFGE profiles of Salmonella isolated from locally purchased poultry products that were indistinguishable from PFGE profiles of Salmonella from clinical isolates submitted to the WA-DOH. When the PFGE profiles from the poultry samples were compared to those found in NARMS’ database, there were eight indistinguishable PFGE matches isolated from chicken breasts, ground turkey, and ground beef from multiple states. While this study found some association between PFGE profiles from raw poultry products and those of clinical isolates from the same geographical area, it does not prove that all of those clinical isolates were infections that resulted from the consumption or handling of poultry.