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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Publications at this Location » Publication #101467
Title: SENSITIVITY OF VARIOUS FECAL SAMPLE COLLECTIONS TECHNIQUES FOR DETECTION OF SAMONELLA TYPHIMURIUM IN FINISH HOGS

Author
item Hurd, Howard
item Stabel, Thomas
item Carlson, Steven

Submitted to: International Symposium on Epidemiology and Control of Salmonella in Pork
Publication Type: Abstract Only
Publication Acceptance Date: 8/7/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Diagnosing the presence of Salmonella in ante mortem hogs is an important first step in conducting preharvest epidemiologic studies. When estimating the prevalence in a population it is important to know the sensitivity of the test being employed. Prevalence estimates made from a test with sensitivity less that 100% require adjustment. Accurate data on the sensitivity of commonly used technique will provide users with the needed adjustment parameter. The objective of this experiment was to estimate, with statistical rigor, the sensitivity of various fecal collection techniques for finishing hogs. Hogs weighing 100-180 pounds were infected intranasally with a moderate dose of Nalidixic acid resistant Salmonella typhimurium. These hogs were tested for the presence of Salmonella by collecting various amounts of feces. The following samples were collected repeatedly from each hog for over a 14-day period: 1) rectal swab; 2) fecal loop (averaging 0.5 g of feces); 3) 1 g feces; and 4) 10 g of feces. In the lab, all samples were handled the same, using accepted culture methods for Salmonella in swine feces. In addition, a one GM sample was submitted to fluorescent PCR detection procedures. Known positive pigs were defined as those found, at postmortem, with Salmonella typhimurium in the ileocecal lymph nodes, ileocecal junction, or the cecum. Preliminary results suggest that there is a significant difference in the sensitivity of each technique.