Salmonella enterica is a Gram-negative, motile, non-sporulating aerobic or facultatively anaerobic rod-shaped bacterium in the family Enterobacteriaceae. There are six known subspecies of S. enterica: S. enterica enterica (I), S. enterica salamae (II), S. enterica arizonae (IIIa), S. enterica diarizonae (IIIb), S. enterica houtenae (IV), and S. enterica indica (VI). There are over 2600 S. enterica serovars that are found in both clinically healthy and sick animals alike. Serovars are referred to as Salmonella followed by the capitalized and unitalicized serovar name (e.g. S. Typhimurium).