Experimental infection of pigs by Salmonella Derby, S. Typhimurium and monophasic variant of S. Typhimurium: comparison of colonization and serology

Publication date: Available online 6 March 2019Source: Veterinary MicrobiologyAuthor(s): María Cevallos-Almeida, Laure Martin, Catherine Houdayer, Valerie Rose, Jean-Marie Guionnet, Frédéric Paboeuf, Martine Denis, Annaëlle KerouantonAbstractSalmonella serovars Derby, Typhimurium and the monophasic variant of Salmonella Typhimurium are the most frequently isolated serovars in pigs in France. To compare the excretion patterns, seroconversion to Salmonella and contamination of the organs of pigs inoculated with strains of all three serovars, we conducted an experimental trial with 28 SPF piglets. Four were used as a negative control, while the other 24 were divided equally into three groups. Each group was inoculated at 7 weeks of age with a different strain: S. Derby (SDb), S. Typhimurium (ST), and the monophasic variant of S. Typhimurium (mST). Fecal and blood samples were collected twice a week up until necropsy, on 21 days post-inoculation (DPI) for half of each group and 49 DPI for the remaining piglets. During necropsy, the tonsils, mesenteric lymph nodes and various intestinal contents were collected from each pig. Salmonella bacteria were quantified in CFU/g by a bacteriological method, and levels of Salmonella antibodies were measured using an ELISA Kit. Piglets inoculated with mST continuously excreted Salmonella in their feces throughout the trial. For the other serovars, at least one piglet was Salmonella-negative on one or several DPI. The quantity of Salmonell...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research