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Flashcards in 06 - Salmonella Deck (22)
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(Salmonella Species)

1. What family?

2. G+ or G-

3. how do they handle oxygen?

4. shape?

1. enterobacteriacea

2. G-

3. facultative aerobic

4. rod-shaped bacterium


there were some corrections on this that I don't really understand



From epidemiological point of view, Salomenella can be classified into 3 main groups... 

1-3. What are they?

1. those infecting only humans (ex S. typhi, paratyphia A and C)

2. those adaped for particular species of vertebrates

3. Salmonella types with no particular host preferences (infect both humans and animals)


1-2. What are the two species of salmonella?

1. S. bongori

2. S. enterica


(Genus: Salmonella)

1. Approximately how many serotypes are known to exists?

Based on what?

2. Members of the genus given names based on what? (4 steps)

1. 2000 serotypes

67 O and numerous H antigen serotypes

2. grouping by epidemiological point of view

animal or syndrome from which they first isolated

place where first reported

antigenic formula


look at slides 8-15 for growth stuff


(Serotyping of Salmonella Enterica)

Based on antigenic structure of Kaufman-White Scheme...

1-3. What are the three criteria?


1. somatic antigen (O) - heat stable

2. capsular antigen (Vi)

3. Flagellar antigen (H - phases 1 and 2) - heat labile


(Antigenic Variation)

In Salmonella Variations in antigenic structure take place

1-4. What are the four kinds of variation?

1. phase variation

2. H - O variation

3. S - R variation

4. Form variation 

a) O variation

b)  V - W variation


(H - O Variation)

1. Loss of what?

2. Proceeds in one or two directions?

3. Mutant non-motile resulting from motile one

4. Is spontaneous change from HO to O forms common?

5. Genetic material responsible for development of the enzyme system that synthesis the flagella is lost or altered.

1. H antigen or flagella

2. one (ie flagellated HO form to non-flagellated O form)

4. no - is rare (and most often irreversible)


(S - R Variation)

Smooth to Rough Variation

1. Change from smooth to rough forms

2. Known to occur in what?

3. Is it an instantatnous change? what happens?

4. Rough organisms give what kind of agglutination?

5. low or high in virulence?

allowing what?

6. do flagellar antigens change?

2. pracitally all bacteria

3. no - is a gradual loss of O antigen thus exposing the core polysaccharide

4. non-specific

5. low

can be used as vaccine strains

6. no


(O and V-W Antigen Variation)

1. What is O Variation?

1. quantitative variation in O antigen


(V - W Variation)

1. This variation affects what?

2. What happens to O and H antigens?

3. Quantitative antigenic changes which take place in Vi antigen are called what?

1. Vi antigen

2. nothing (remain unchanged)

3. the V-W variation


1. is salmonella a lactose fermenter?

2. do they produce hydrogen sulfide (black pigment)?

1. no

2. yes


(Phase Variation)

1. Flagellar (H) antigens are what?

2. H antigen often exists in one of two different phases. An individual bacteria will have flagella composed of antigens either in phase 1 or phase 2

Bacteria, which are originally in one phase, may switch to the other phase when?

what is this switch called?

3. Some Salmonella are monophasic and others are non-motile. 

Do non-motile strains demonstrate phase variation?

4. Identification of both phases is necessary for what?

1. proteins localized in the flagella of motile species of Salmonella

2. during multiplication

phase variation

3. no

4. for identification of Salmonella serotype




1-5. What are the five virulence factors?

1. antigenic phase variation

2. sequestratino of nutritional factors

3. resistance to serum killing

4. antimibrobial resistance

5. pathogenecitiy islands



1. Leading Cause of human foodborne illness worldwide

2. 1-5 million estimated human cases in the US yearly

3. What are the three most common serotypes of Salmonella isolated from humans in the US?

3. typhinurium, enteritidis, and newport


(Salmoneloosis in Humans)

1. Caused by certain Salmonella serotypes

2. Salmonella paratyphi A, S. paratyphi B, S. paratyphi C, and S typhi affect only what?

3. Human infections are also caused by non-host adapted Salmonella

2. humans


(Human Salmonellosis)

(Salmonella serotype Typhi)

1. Causes what?

2. Typical symptoms may be preceded by what?

3. incubation?

4. symptoms?

5. Risk is low in the US, but it is higher among international travelers

1. Typhoid fever

2. acute gastroenteritis (coming on shortly after consumption of cantaminated food and water)

3. 7-14 days

4. fever, diarrhea, vomiting, abdominal tenderness, death in some cases (12-30%)


(Human Salmonellosis)

(Salmonella serotype Typhi)

1. After ingestion...

multiplies where?

enters what?

disseminates thoughout body using what?

2. Relapses may occur during convalescence due to what?

3. (Carriers) typhoid bacillus may localize where?

4. diagnosis?

5. what are used as vaccines?

1. GI tract

lymphatic system

disseminates throughout the body by blood stream

2. Reinvasion of blood stream from the tissues in which typhoid bacilli are still proliferating

3. in the gall bladder or bile ducts (may persist there from any years after convalescence)

4. culture of blood, feces, urine or bile

5. inactivated bacterins or live attenuated strains