Lecture 28 - GI/Liver Bacteriology 6 Flashcards
describe the characteristics of salmonella enterica
gram -
rod
anaerobe
non-lactose fermenter
motile with flagella
what is the habitat of S. enterica
- GI tract of all animals
- soil and environment
T/F: salmonella enterica is zoonotic
TRUE
How is salmonella named?
including species, subspecies and serotype (host/disease/location)
what are the 4 ways salmonella is transmitted
- oral
- transovarian
- vector
- environment
what are the 6 salmonella virulence factors
- adhesins
- flagella
- type 3 secretion system (T3SS)
- siderophores
- LPS
- heat shock proteins
describe adhesins
fimbrial proteins attach to GI mucosa
describe flagella
motility
describe T3SS
injecting bacterial proteins into cell
describe siderophores
bind iron needed for nutrition and invasion
describe LPS
endotoxic lipid A component and stimulation of proinflammatory cytokines
describe heat shock proteins
essential for intracellular survival in macrophages
summarize the pathogenesis of salmonella (causing D+)
- adhere to epithelium
- invade and replicate intracellularly
- secrete toxins (increase Cl- secretion and Na+ absorption)
- neutrophil recruitment and inflammation
- malabsorptive and secretory D+ with blood
what are the 4 presentations of salmonella clinically
- inapparent infection
- recovered carrier state
- gastroenteritis*
- septicemia
what salmonella serotypes are present in ruminants
- dublin
- typhimurium
- newport
describe how salmonella affects neonates, cows and adult cattle
neonates: 2-6wk/o, fever and D+, death
cows: abortion
adult cattle: fever, severe D+ with blood and mucus
What is the most diagnosed infectious diarrhea in adult horses
salmonella
what salmonella serotypes are adult horses typically infected with
Typhimurium
describe how salmonella affects adult horses and foals
foals: septicemia and high mortality
adults: fever, severe D+ with[out] blood and mucus
what salmonella serotypes affect pigs
- Typhimurium
- Chloraesuis
what happens clinically to pigs infected with salmonella
acute septicemia or chronic debilitating intestinal disease
describe non-host-adapted poultry salmonella
- “paratyphoid”
- many serotypes
- motile strain
- ingestion transmission
describe host-adapted poultry salmonella
- Fowl typhoid (Gallinarum)
- Pullorum Disease (Pullorum)
- non-motile
Fowl Typhoid
- S. Gallinarum
- birds of all ages
- ova transmission
- acute septicemia or chronic enteritis/hepatitis
Pullorum Disease
- S. pullorum
- 2-3 wk/o chicks
- ova transmission
- septicemia or chronic carriers
describe salmonella in cats and dogs
- clinical disease is uncommon (D+ fever, septicemia, etc.)
- associated with consumption of contaminated food, treats, or raw meat
___ of salmonella positive dogs were nonclinical
55%
what is the single most pre-disposing factor for salmonella shedding
stress
how many organisms of salmonella cause disease in humans
1-5 organisms
how is salmonella diagnosed?
- history of disease and age group
- culture
- serology
- PCR
what are the 3 benefits of PCR over serology
- faster turn-around
- more sensitive
- not reliant on special media to promote growth
what is the treatment of salmonella
fluid and elyte therapy +/- NSAIDS for fever reduction
T/F: vaccination for salmonella is available
TRUE
how is salmonella controlled
- management of carriers and environment
- use of milk replacer
- isolation of clinically affected animals
