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Salmonella enterica is a rod shaped, flagellated, aerobic, Gram-negative bacterium, and a member of the genus Salmonella.
S. enterica has an extraordinarily large number of serovars or strains—over 2000 have been described. The biomedically most
relevant subspecies is called S. enterica ssp. enterica, whose following Serovars have special clinical significance in human
disease:
Salmonella enterica Serovar Typhi (historically elevated to species status as S. Typhi) is the disease agent in typhoid fever.
Salmonella enterica Serovar Typhimurium (also known as S. Typhimurium) can lead to a form of human gastroenteritis sometimes
referred to as salmonellosis.
Salmonella enterica Serovar Paratyphi A is associated with paratyphoid fever. It is sometimes known as Salmonella Paratyphi.
Most cases of salmonellosis are caused by food infected with S. enterica, which often infects cattle and poultry, though also other animals such as domestic cats and hamsters
have also been shown to be sources of infection to humans. However, investigations of vacuum cleaner bags have shown that households can act as a reservoir of the bacterium;
this is more likely if the household has contact with an infection source, for example members working with cattle or in a veterinary clinic.
Raw chicken and goose eggs can harbor S. enterica, initially in the egg whites, although most eggs are not infected. As the egg ages at room temperature, the yolk membrane begins
to break down and S. enterica can spread into the yolk. Refrigeration and freezing do not kill all the bacteria, but substantially slow or halt their growth. Pasteurizing and food
irradiation are used to kill Salmonella for commercially-produced foodstuffs containing raw eggs such as ice cream. Foods prepared in the home from raw eggs such as mayonnaise,
cakes and cookies can spread salmonella if not properly cooked before consumption.
Abbreviated from Wikipedia.
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