BACTE LEC FP: STAPHYLO Flashcards
What is the shape and Gram reaction of Staphylococcus?
Perfectly spherical Gram-positive cocci
What is the size range of Staphylococcus cocci?
Approximately 0.5 to 1 µm in diameter
What is the colony arrangement of Staphylococcus?
They grow in clusters like a bunch of grapes
What is the colony pigment of S. aureus?
Golden yellow
What is the colony pigment of S. albus/S. epidermidis?
White
What is the habitat of S. aureus?
Nasal passages, skin, oral cavity, and intestinal tract
What is the habitat of S. epidermidis?
Inhabitant of the skin
What is the role of surface proteins in Staphylococcus?
They promote colonization of host tissues
What does the fibronectin binding protein promote?
Attachment to epithelial and endothelial surfaces and blood clots
What does the clumping factor bind to?
Fibrinogen and fibrin
What does the collagen-binding factor help infect?
Indwelling medical devices like IV catheters and prosthetic joints
What component inhibits phagocytosis in Staphylococcus?
Capsular polysaccharide and protein A
What is the function of protein A in S. aureus?
Binds IgG the wrong way, disrupting opsonization and phagocytosis
What is the function of leukocidin?
Toxin that specifically acts on polymorphonuclear leukocytes
What is the function of alpha toxin?
It damages membranes and causes leakage of cellular contents
What is the function of beta toxin?
It is a sphingomyelinase causing incomplete hot-cold lysis of sheep RBCs
What is the function of delta toxin?
It is a phospholipase; its disease role is unclear
What is the function of gamma toxin?
It forms a two-part toxin with leukocidin to damage membranes
What is the role of Panton-Valentine leukocidin (PVL)?
Potently leukotoxic and involved in necrotizing skin infections
What do enterotoxins cause?
Diarrhea and vomiting (staphylococcal food poisoning)
What is TSST-1 responsible for?
75% of toxic shock syndrome cases, especially menstrual cases
What does the epidermolytic (exfoliative) toxin cause?
Scalded skin syndrome in neonates
What is the function of coagulase?
Forms staphylothrombin with prothrombin to activate thrombin and form clots
What is the function of staphylokinase?
Activates plasminogen to dissolve fibrin clots
What does FAME do?
Modifies antibacterial lipids in abscesses to prolong bacterial survival
What is the function of hyaluronidase?
Hydrolyzes hyaluronic acid (cementing substance)
What does S. epidermidis commonly infect?
Prosthetic devices and catheters with biofilm production
What are the catalase and coagulase reactions of S. aureus?
Catalase and coagulase positive
What are the catalase and coagulase reactions of S. epidermidis?
Catalase positive, coagulase negative
Which staphylococcus ferments mannitol?
S. aureus
What does S. aureus cause in horses?
Botryomycosis
What does S. aureus cause in cattle?
Mastitis
What does S. aureus cause in lambs?
Tick pyemia
What does S. aureus cause in poultry?
Purulent synovitis or bumblefoot
What does S. aureus cause in rabbits?
Exudative dermatitis
What does S. hyicus cause in pigs?
Exudative epidermitis (Greasy pig disease)
What are diagnostic tools for Staphylococcus?
Smear, BAP culture, Mannitol salt agar, Coagulase, DNase
Is there an effective vaccine against Staphylococcus?
No effective vaccine
What are two resistance factors of Staphylococcus?
Beta lactamase and methicillin resistance (MRSA)
