Staphylococcus Flashcards
what gram, shape, and arrangement are stapylococcus
-gram positive
-cocci
-grape like clusters
respiration, motility, spore forming?
-facultative anaerobe
-non motile (non flagellated)
-non spore forming
catalase, media?
-catalase positive (detoxify H2O2)
-grow on high salt media – mannitol salt agar
what does mannitol salt agar support and inhibit growth of
-supports most gram positive bacteria
-inhibits most gram negative bacteria
-inhibits streptococcus (gram+ but hates salt)
what does staph aureus do to mannitol salt agar
ferment mannitol and change agar color from red to yellow
what does staph epidermis do to mannitol salt agar
does not ferment mannitol, no color change (stays red)
a, B, y hemolysis on blood agar
-a – incomplete hemolysis, green
-B – compete hemolysis, clear
-y – no hemolysis, no change in media
what causes yellow color of staph aureus on blood agar
-carotenoid pigment staphyloxanthin (antioxidant)
coagulase test
positive = more pathogenic
negative = less pathogenic, many in humans
habitat of staphylococcus
-skin
-nasal cavity
-buccal cavity
-nasopharynx
-mammary gland
-groin region
risk factors of staphylococcus
-opportunistic pathogen
-parasitic, fungal, viral infection
-shearing sheep, grooming dogs
-nutritional imbalances (zinc, vitamin deficiency)
body structures – cell wall
-bacterial viability
-homeostasis
-protect from host lysozyme
body structures – protein A
-grabs immunoglobulin so it can’t grab onto pathogens
-bind Fc of IgG
-blocks immune response, opsonization
body structures – binding or clamping factors
-attachment to host proteins
body structures – capsule (slime layer)
-adhesion
-prevents chemotaxis
-inhibit phagocytosis by polymorphonuclear leukocytes
enzymes – hyaluronidase
-breaks down connective tissue between adjacent cells
enzymes – catalase
- protects against host ROS
enzymes – coagulase
-clots blood to hide in it
enzymes – staphylokinase
-lyses clots (fibrin) to come out of it and disperse itself
enzymes – lipase
-digest lipids – can colonize skin surface and sebaceous glands
enzymes – protease
-destroys tissue protiens
enzymes – B-lactams
-inactivate B-lactam drugs, survive treatment
toxins – hemolysin
- destroys RBC, neutrophils, macrophages, platelets
toxins – cytolytic toxins (leuckocidin)
-destroy cell membranes of host cells (leukocytes)
-destroy WBC
toxins – exfoliative toxin
-separate skin layers, resulting in impetigo and skin layer peel off
toxins – toxic shock syndrome toxin
-superantigens (mass T cell activation)
toxins – enteotoxins
-food poisoning by stimulating gut mobility
-superantigens
staphylococcal pathogenesis steps
-adhesion and attachment on host cell surface or matrix
-biofilm formation on host cell surface
-advance for intracellular invasion, multiplication, persistence in host cell
-inflammation, abscess formation, necrosis, bacteria encapsulation
2 possible final outcomes of staph pathogenesis
-bacteria hide in dormant small colony variant formed in sequestra
-abscess maturation, rupture, bacterial spread, bacteremia
staphylococcus that are coagulase positive
S. aureus – mammals, birds
S. hyicus – pigs
S. pseudintermedius – pets
S. schleiferi – pets
staphylococcus that are coagulase negative
S. chromogenes – mammals
S. felis – pets
S. epidermis – foot odor in humans
the 4 directions staph species advance from
-pus, abscess
-ear
-mammary
-urogenital
what does S. aureus generally cause
-abscess
-dermatitis
-mastitis
-septicemia
-endocarditis
-meningitis
-osteoarthritis
-surgical lesion infection
what does S aureus cause in cattle
-mastitis
-teat based pustules/impetigo
-gangrenous teat
what does S aureus cause in sheep
-mastitis
-tick pyemia of lambs
-dermatitis or torn skin
-periorbital dermatitis
what does S aureus cause in goats
-mastitis, dermatitis, subacute or peracute mastitis
what does S aureus cause in pigs
- mastitis (impetigo)
-endometritis
what does S aureus cause in horses
-mastitis
-botryomycosis of spermatic cord after castration
what does S aureus cause in poultry
-septicemia
-foot/joint pyogranulomatous lesion (bumble foot)
-arthritis
what does S aureus cause in dogs and cats
-suppurative lesions
what does S pesudintermedius cause in dogs and cats
-pyoderma
-pyometra
-otitis externa
-pneumonia
-osteoarthritis
-wound
-eyelid and conjunctivitis
what does S schleiferi cause in dogs and cats
-otitis external
-otitis media
-head shaking and tilting
-skin reddening
-hair loss
-scratching and itching
-pyoderma
what does S felis cause in cats
-otitis
-abscess
-dermatitis
-cystitis
-conjunctivitis
what does S chromogenes cause in cattle
-subclinical mastitis
what does S chromogenes cause in pigs
-exudative epidermitis
what does S chromogenes cause in horses and cats
-dermatitis (rare)
what does S hyicus cause in pigs
-exudative epidermatitis (greasy pig disease) in young pigs
-septicemia (fatal)
-septic polyarthritis
-metritis
-vaginitis
what does S hyicus cause in cattle
-mastitis
what does S hyicus cause in horse
-skin infection
treatment of staph
one of the multidrug resistance species
what has S aureus acquired resistance to
Methicillin
vancomycin
control and prevention
-improving hygiene and wellbeing
-tick control of lambs
-good hygiene at milking
what causes cutaneous pus and peeling of skin in huamns
S aureus
what causes cutaneout pus and peeling of skin layers in pigs
S hyicus
what casues peeling skin, cutaneous pus, pus form ear/uterus in pets
-pyoderma – S pseudointermedius, sometimes S aureus or S schleiferi
-otitis externa in dogs – S schleiferi
-otitis externa in cats – S felis
what casues pus/gangrene in udder and teats
-mastitis – S aureus
-subclinical mastitis – S chromogenes
what casues pus forming bacteria in skin infested by ticks in sheep
-tick pyremia – S aureus
what causes pus and nodule forming bacteria in skin of lips/limbs, utter/scrotum, septicemia in horses
-S aureus
what causes pus forming in joints of legs/foot/wings, gangrene of skin, and septicemia in poultry
S aureus
what causes bumblefoot in poultry
S aureus
