Salmonella Flashcards
Salmonella shares all characteristics that were described in Enterobacteriaceae. What are 5 unique characteristics?
- lactose non-fermenter
- urease negative
- produces hydrogen sulfide (rotten egg smell providing black colonies
- motile by pertrichous flagella
- no hemolysis (gamma)
What 2 species of Salmonella are non-motile?
- S. gallinarum
- S. pullorum
(devastating in poultry)
What are the 2 media widely used for culturing Salmonella? What 2 selective media are used?
- MacConkey agar (yellow, no color change)
- eosin methylene blue agar
- brilliant green agar
- Salmonella and Shigella agar
What 2 enrichment media are used for injured Salmonella isolation? What bacterial growth does it inhibit?
- tetrathionate broth
- selenite cysteine broth
coliforms (CEEK)
Where is Salmonella a commensal part of the environment? What is one exception?
digestive tract of mammals, birds, reptiles, amphibians, fish, and invertebrates
S. typhimurium is part of the normal flora of reptile and amphibian skin
How is Salmonella transmitted? How does it enter and exit hosts?
oral-fecal transmission
ENTRY: ingestion of bacteria with water, feed, or food (eggs, milk, meat, fish)
EXIT: feces
What species of Salmonella is not excreted fecally?
S. pullorum undergoes trans-ovarian transmission to next generation of poultry
What antigen do S. gallinarum and S. pullorum lack?
H antigen —> non-motile = no flagella
What antigens contribute to the diversity of Salmonella serotypes?
LPS = O antigen
flagella = H antigen
What 2 species of Salmonella are the 2500 serotypes classified into? What subspecies is responsible for 99% of disease?
- S. enterica
- S. Bongori (cold-blooded animals)
S enterica —> enterica I
What are the 3 categories of S. enterica (subspecies enterica I)?
- HOST SPECIFIC: specialists affecting only 1 host
- HOST ADAPTED: prefer 1 host, but can affect others
- GENERALISTS: no selection of preference - can affect multiple species*** (Salmonella serovars)
What 2 Salmonella enterica do not have zoonotic potential?
S. gallinarum and S. pullorum —> do not affect mammals, specialized to attack birds
(all the rest are zoonotic)
What are the top 3 serotypes of Salmonella that affect humans>
- S. typhinurium*
- S. newport
- S. enteritidis*
What 3 Salmonella cause the top 7 priority diseases of the National Poultry Improvement Plan (NPIP)? What is done if a flock is infected with these species?
- S. pullorum
- S. gallinarum
- S. enterica var enteritidis
ban any shipment from a poultry farm or hatchery if infected —> all must be inspected and tested to be free from Salmonella
What caused a major Salmonella outbreak relating to wild songbirds?
songbirds can carry Salmonella while looking healthy and clean and spread/transmit it to other animals and humans