SNIPPET

ontyphoidal salmonellosis is one of the leading Ncauses of acute bacterial gastroenteritis in the
United States, responsible for an estimated 1.4 million cases of illness annually. Many animals, both domestic
and wild, are colonized by Salmonella spp, usually harboring the bacteria in their gastrointestinal tracts with
no apparent signs of illness. Hence, salmonellae are often present in feces excreted by healthy animals and
frequently contaminate raw foods of animal origin through fecal contact during production and slaughter.
Although the genus Salmonella consists of more than 2,400 serovars, most human cases of salmonel-
losis in the United States are caused by 4 serovars. For example, in 1995 the US Centers for Disease Control
and Prevention (CDC) reported that approximately 60% of human cases were caused by Salmonella enteri-
caser Enteritidis (24.7%), Sser Typhimurium (23.5%), S ser Newport (6.2%), and S ser Heidelberg (5.1%).
These same 4 serovars represented 46.4% of the isolates from nonhuman sources that year. <SNIP>