Micro

• What shape are Gram-positive cocci?

  Spherical

  
• Name two types of Gram-positive cocci.

  Staphylococci and Streptococci

  
• What are the two most common groups of Gram-positive organisms of medical importance?

  Staphylococci and Streptococci
• What does the term "staphylococcus" mean?

  It means "bunch of grapes"
• What is a key characteristic of Staphylococci regarding their survival?

  They are hardy and can survive well outside the animal host
• Why are many Staphylococci considered harmless?

  They are normally harmless commensals
• How can Staphylococcus aureus infections vary in severity?

  Infections can be trivial or rapidly fatal

  
• What color are the colonies of Staphylococcus aureus?

  Golden
• What is the significance of coagulase production in Staphylococcus aureus?

  It converts fibrinogen to fibrin, protecting from the immune system
• What is a common characteristic of MRSA strains?

  They are often resistant to multiple antibiotics
• What is the role of Protein A in Staphylococcus aureus?

  It binds to IgG and prevents opsonization

  
• What is the function of fibronectin-binding protein in Staphylococcus aureus?

  It promotes binding to mucosal cells and tissue matrices
• What are cytolytic exotoxins in Staphylococcus aureus known for?

  They attack mammalian cell membranes

  
• What is a superantigen exotoxin's role in Staphylococcus aureus infections?

  It stimulates an enhanced T cell response

  
• What is the most common type of infection caused by Staphylococcus aureus?

  Localized skin infections
• What is impetigo, and who is it most common in?

  It is a superficial, rapidly spreading infection, especially in children

  
• What can localized skin infections from Staphylococcus aureus lead to if untreated?

  They can lead to bacteremia
• What is the clinical significance of deep infections caused by Staphylococcus aureus?

  They can cause significant localized damage
• What is septicemia/bacteremia in relation to Staphylococcus aureus?

  It often arises from a starter lesion on the skin
• What is toxic shock syndrome, and what are its symptoms?

  It is a severe condition with fever, rash, vomiting, and multi-organ involvement
• What causes scalded skin syndrome in Staphylococcus aureus infections?

  It results from specific toxins leading to epithelial desquamation

  
• What is the treatment approach for destructive infections caused by Staphylococcus aureus?

  Aggressive treatments including incision, drainage, and antibiotics
• What is the first-line antibiotic choice for treating Staphylococcus aureus infections?

  Flucloxacillin, which is resistant to beta-lactamase
• What is the significance of MRSA in healthcare settings?

  MRSA is often healthcare-associated and has worse outcomes
• What is the role of Staphylococcus epidermidis in human health?

  It is part of the normal flora, especially on the skin
• What is the clinical significance of Staphylococcus saprophyticus?

  It can cause cystitis, especially in younger women
• What are the key points in the overview of Staphylococci?

  • Gram-positive cocci
  • Includes Staphylococcus and Streptococcus
  • Can cause a range of infections
  • Important virulence factors
• What are the major clinical significances of Staphylococcus aureus infections?

  • Localized skin infections
  • Septicemia/bacteremia
  • Endocarditis
  • Pneumonia
  • Toxic shock syndrome
  • Scalded skin syndrome
  • Gastroenteritis
• What are the treatment options for Staphylococcus aureus infections?

  • Aggressive treatments for destructive infections
  • Source control (incision/drainage)
  • Antibiotics (e.g., flucloxacillin)
• What are the characteristics of coagulase-negative staphylococci (CNS)?

  • Not Staphylococcus aureus
  • Lower virulence
  • Part of normal flora
  • Associated with implants and catheters
• What is the significance of Staphylococcus saprophyticus in urinary tract infections?

  • Causes cystitis in younger women
  • Part of normal flora of the genital tract