Salmonelliosis Flashcards
What is salmonella (features) ?
- Gram negative rod shaped faculative anerobic bacterium
- Motile species
- Zoonotic
- Causes disease in humans and livestock
*
What are the two species of salmonella?
- S.enterica
- S.bongori
How many subspecies is S.enterica divided into?
Six
What do the serovars gallinarum and pullorum cause?
“fowl typhoid” and “pullorum disease” respectively
they are both non-motile
What does the serovar typhi cause?
“typhoid fever” which is the classic enteric fever
What do the serovars Paratyphi-A and Paratyphi-B cause?
mild forms of enteric fever in humans, most strains do not produce hydrogen sulfide
What do the serovars Cholerae-suis and Typhi-suis cause?
Severe disease in pigs
How many serotypes of salmonella are there?
Over 2500
And they are distributed worldwide
How many cases of salmonella are there a year, approximately?
11,000
What is the main cause of salmonella in humans?
Poultry and Poultry products
What kind of diseases does salmonella cause in humans?
Diarrhoeal diseases
Name some of the selective media that salmonella can grow on?
- XLD
- BGA
- Rappaport
- Selenite Broth
- Rambachs
- Chromogenic agar
Name 5 types of serotyping
- Slide agglutination
- PCR
- LAMP
- Arrays
- WGS
Why is salmonella so important?
It causes an economically important clinical disease in livestock and humans
What does Salmonella Choleraesuis cause?
Severe outbreaks of clinical disease similiar to swine fever
What does Salmonella Typhisuis cause?
Chronic enteritis in young pigs
What does Salmonella Typhimurium cause?
Enteritis and septicaemia
What does S.Dublin in cattle cause?
terminal gangrene, meningitis, enteritis, osteomyelitis, and septicaemia
What does S. Typhimurium and S. bovismorbifican cause
Enteritis and septicaemia
* Important cause of abortion in the last six weeks of pregnancy
What serovars are responsible for typhoid or enteric fever?
Typhi and Paratyphi
they both cause systemic illness
What does Salmonella Pullorum look like in poultry
Bacillary white diamond
What does salmonella Gallinarum look like in poultry?
Fowl Typhoid
What does salmonella arizonae look like in poultry?
Severe enteritis and septicaemia
Why is salmonella an issue in poultry?
- Intensification
- No vaccine available for broilers
- Vertical transmission
- Emerging pathotypes
- Persistents in low numbers below detection levels
- Use of raw eggs
How would you control salmonella in livestock?
- Vaccination
- Biosecurity
- Wildlife/ Vermin control
- Surveillanvce
What are the virulence determinants of salmonella?
- Fimbriae
- Flagella
- Outer Membrane Proteins
- Secreted Proteins
- Plasmids
- Pathogenicity Islands
- LPS
What is the type III secretion system?
- First TTSS is encoded by a salmonella pathogenicity Island and translocates bacterial proteins into the host cell which is neccesary for invasion
- The second TTSS is encoded by the SPI-2 and translocates proteins across the vacuolar membrane that act to enable intracellular replication
What is SOPD?
Contributes to fluid secretion and Inflammatory resonse during Salmonella Infection
What is SOPA?
E3 Ubiquitin LIgase and regulates Salmonella induced Intestinal Inflammation
What is SOP E/ E2?
interacts with the central regulators of the host cell actin cytoskeleton
What is the Salmonella Containing Vacuole?
- Inside host cells, the bacterium is enclosed in a membrane-bound compartment, called the salmonella containing vacuole
- Intracellular replication of salmonella requires the translocation of effector proteins into the host cytosol
- the SifA effector protein is important for the membrane stability of the SCV
What is the role of acid resistance?
- Helps salmonella survive in the host gut
- Adaptive response
- Salmonella Typhimurium possesses two general
forms of inducible acid tolerance.
What is the role of the flagella?
Important for invasion and Intracellular survival
What are the LPS important for?
The colonisation of chickens
