Porcine Salmonellosis Study Guide

Overview and Clinical Importance

Salmonellosis is one of the most important bacterial diseases affecting swine worldwide, with significant implications for both animal health and public health as a major foodborne zoonosis. The disease is caused by Salmonella enterica serovars, with clinical presentations ranging from acute septicemia to chronic enterocolitis, or subclinical carrier states.

Nearly all swine herds are infected with one or more of the approximately 2,500 Salmonella serotypes. The two most clinically significant serotypes in pigs are S. Choleraesuis (causes septicemic disease) and S. Typhimurium (causes enteric disease). Recently, S. enterica serotype 4,[5],12:i:- (monophasic variant of S. Typhimurium) has emerged as a predominant serotype in diseased swine.

Etiology and Epidemiology

Causative Agents

Salmonella enterica is a Gram-negative, facultatively anaerobic, rod-shaped bacterium belonging to the family Enterobacteriaceae. The organism colonizes the intestinal tract, particularly the ileum, cecum, and spiral colon via Peyer's patches.