What are 3 likely antigens for Salmonella?
Salmonellae are Gram-negative, flagellated, facultatively anaerobic bacilli possessing three major antigens: H or flagellar antigen; O or somatic antigen; and Vi antigen (possessed by only a few serovars). H antigen may occur in either or both of two forms, called phase 1 and phase 2.
What food is associated with Salmonella bacteria?
Foods Linked to U.S. Outbreaks of Salmonellosis Past U.S. outbreaks of salmonellosis have been associated with meat products, poultry products, raw or undercooked eggs and dough, dairy products, fruits, leafy greens, raw sprouts, fresh vegetables, nut butters and spreads, pet foods and treats.
Does Salmonella have antigen?
Salmonella paratyphi B was found to possess, apart from specific O and H antigens, a surface K antigen. This is a distinct antigen having strict serological specificity. Purified K antigen displayed anodic mobility in immunoelectrophoresis.
What is Vi antigen in Salmonella?
In Salmonella enterica, the virulence capsular polysaccharide, known as “Vi antigen,” is produced by human-restricted serovar Typhi (hereafter S. Typhi, the etiological agent of typhoid fever) and serovar Paratyphi C, but it is absent in other serovars commonly associated with gastroenteritis.
What antigen has Salmonella Enterobacteriaceae?
Antigenic Structure As with all Enterobacteriaceae, the genus Salmonella has three kinds of major antigens with diagnostic or identifying applications: somatic, surface, and flagellar.
What are the antigens associated with Salmonella typhi and S Paratyphi?
enterica sub-species enterica serotype typhi) (186) and paratyphoid is caused by either Salmonella paratyphi A, B, or C. Serologically S. typhi is LPS antigen 09, 12, protein flagellar antigen Hd, and capsular polysaccharide antigen Vi positive. Salmonella paratyphi B is also known as S.
Which of the following foods is most commonly associated with Salmonella?
Salmonella outbreaks are commonly associated with eggs, meat and poultry, but these bacteria can also contaminate other foods such as fruits and vegetables. Foods that are most likely to contain Salmonella include raw or undercooked eggs, raw milk, contaminated water, and raw or undercooked meats.
What are the most common sources of Salmonella bacteria?
Salmonella bacteria live in the intestines of people, animals and birds. Most people are infected with salmonella by eating foods that have been contaminated by feces. Commonly infected foods include: Raw meat, poultry and seafood.
Which antigens are present on the surface of Salmonella typhi?
One specific surface antigen is well known: the Vi antigen. The Vi antigen occurs in only three Salmonella serovars (out of about 2,200): Typhi, Paratyphi C, and Dublin. Strains of these three serovars may or may not have the Vi antigen.
What is H and O antigen?
The bacteria’s surface are covered with lipopolysaccharide (LPS). The outermost portion of the LPS is the O antigen. Flagella are whip-like tails that bacteria use to move around. Flagella is the whole structure, while the slender threadlike portion of the flagella is called the H antigen.
What is K antigen in bacteria?
Capsular polysaccharide (CPS) or K antigen is a covalently attached surface associated virulence factor that conceals the bacterial surface and helps it to escape from host self-defense mechanism (6–8).
Which antigen is present in Salmonella typhi?
How are the O and H serotypes of Salmonella determined?
The H antigens are distinguished by the protein content of the flagella. Each O and H antigen has a unique code number. Scientists determine the serotype based on the distinct combination of O and H antigens. Salmonella have many different serotypes.
Why does Salmonella fail to agglutinate with O-antiserum?
Many strains of Salmonella (S. Typhi) fails to agglutinate with O-antiserum. When freshly isolated, this is due to presence of a surface polysaccharide antigen enveloping the O-antigen. Felix and Pitt who first described this antigen found out that it was associated to virulence and thus named it vi-antigen.
What are the sources of Salmonella in food?
Answer: all are potential sources of Salmonella infection that have been associated with recent outbreaks in the U.S.. While we mostly think of eggs and poultry products as carriers of Salmonella, pets, livestock, produce, and soil can also spread infection.
What kind of phage typing is used for Salmonella?
As mentioned previously, typing of Salmonella is based on the recognition of bacterial surface antigens: the thermostable polysaccharide cell wall or somatic (‘O’) antigens and the thermolabile flagella proteins or ‘H’ antigens. It is also possible to subtype Salmonella serotypes on the basis of phage typing.