Staphylococcus Flashcards
What is the number one thing to remember when determining how to treat staphyococcal infections?
Staphylococci are opportunistic pathogens. Primary cause needs to be eliminated!
Staphylococcus are commensals of:
skin and mm: nose, lower UG tract, GI tract
Staphylococcus spp are responsible for causing what type of infections?
Supperative; abscesses
Staphylococcus species of veterinary importance
S. aureus
S. pseudintermedius
S. hyicus
CoNG
Staphylococcus virulence factors
Protein A Coagulase TSST Hemolysin Enterotoxins
Which virulence factor of staphylococcus spp helps with immune evasion and anti-opsonization by binding (sequestering) antibodies?
Protein A
How does coagulase increase the virulence of staphylococcal spp?
Gives the bacterium a fibrin coat by turning fibrinogen into fibrin, which allows the bacterium to resist phagocytosis
Which staphylococcal spp are coagulase negative?
CoNG
TSST is responsible for:
Toxic Shock Syndrome
Symptoms of TSS:
Fever, headache, eye redness, hypotension, kidney failure
Virulence factor that acts as a superantigen, causing increased cytokine release and tissue destruction:
TSST
Virulence factor that plays a role in staphylococcal food poisoning:
Enterotoxins
Which staphylococcus species is responsible for contagious mastitis in cattle, botryomycosis in horses, and bumble foot in chickens?
Staphylococcus aureus
Bovine staphylococcal mastitis caused by S. aureus usually presents as:
Subclinical disease
BSM caused by S. aureus can take what 3 forms?
Subclinical
Acute
Peracute gangrenous
What issue in mastitis carrier hosts allows S. aureus to survive at subclinical levels?
impaired phagocyte function
A cow on your farm has a black, swollen, sore udder, seems depressed, and hasn’t been eating. She also hasn’t been producing any milk. What is your diagnosis?
Peracute gangrenous contagious mastitis caused by S. aureus
A farmer calls you about one of his cows who has a severely swollen and fibrotic udder, and whose milk is purulent with clots. What is your diagnosis?
Acute contagious mastitis caused by S. aureus
A farmer informs you that during regular testing of somatic cell counts in his cows’ milk, one of them showed somatic cells over 100,000, and it seemed as though one of her ducts may have been blocked. What is your diagnosis and what do you recommend to the farmer?
Subclinical contagious mastitis caused by S. aureus.
Recommend segregation of infected cows and treating them with antibiotics. These cows should be milked last from now on. Cows with chronic mastitis will need to be culled.
What is dry cow therapy?
Each cow is given a dry cycle after each lactation cycle. Abx are given right after a lactation cycle, at the beginning of each dry cycle.
S. aureus causes what post-castration complication in horses?
Botryomycosis
A horse you castrated last week now has microabscesses and granulomatous supperative lesions on the spermatic cord. What is your diagnosis and how can you treat the problem?
Botryomycosis caused by S. aureus.
Treat with surgical intervention and long term antibiotics
Your client just noticed that many of his chickens have dermatitis on their feet, and he’s worried it will spread to the turkeys he keeps nearby. What is your diagnosis and how can he prevent the problem in the future? What should be be aware of in his flock of turkeys?
Bumble Foot caused by S. aureus.
Recommend practicing good husbandry, soft, clean bedding, and preventing abrasions to the chicken’s feet.
Infections in turkeys can cause septicemia
