Flashcards in this deck (22)

• What are the key features of Staphylococcus aureus in osteomyelitis?

  • Classification: Gram-positive cocci
  • Common Cause: Most common organism for osteomyelitis
  • Transmission: Hematogenous spread, direct inoculation
  • Pathogenesis: Forms biofilm, adheres to damaged bone
  • Clinical Disease: Osteomyelitis, complications include abscess, fractures
  • Diagnosis: Elevated WBC, blood culture, biopsy
  microbiology osteomyelitis
• What distinguishes Staphylococcus epidermidis in osteomyelitis?

  • Associated with indwelling prosthetic devices
  microbiology osteomyelitis
• What is a key feature of Streptococcus viridans in osteomyelitis?

  • Linked to dental sources like abscessed tooth
  microbiology osteomyelitis
• How does Escherichia coli typically spread in osteomyelitis?

  • Spreads from a urinary tract infection (UTI)
  microbiology osteomyelitis
• What is the association of Neisseria gonorrhoeae with osteomyelitis?

  • Associated with gonorrhea, a sexually transmitted infection
  microbiology osteomyelitis
• What is the significance of Pseudomonas sp. in osteomyelitis?

  • Common in puncture wounds and among intravenous drug users
  microbiology osteomyelitis
• What patient condition is Salmonella sp. associated with in osteomyelitis?

  • Strongly associated with sickle cell disease
  microbiology osteomyelitis
• What is the role of Mycobacterium tuberculosis in osteomyelitis?

  • Causes osteomyelitis secondary to tuberculosis
  microbiology osteomyelitis
• What are the key features of Eumycetoma-causing fungi?

  • Classification: True fungi causing chronic infection
  • Identifiers: Painless mass, multiple sinuses, discharge with grains
  • Microscopy: Thick, segmented hyphae
  microbiology mycetoma
• How is Eumycetoma transmitted?

  • Through traumatic inoculation, often via thorn punctures
  microbiology mycetoma
• What is the pathogenesis of Eumycetoma?

  • Organism introduced → granulomatous reaction → chronic infection spreads
  microbiology mycetoma
• What are the major clinical diseases caused by Eumycetoma?

  • Eumycetoma (Madura foot), affecting feet, hands, back, gluteal region
  microbiology mycetoma
• What diagnostic methods are used for Eumycetoma?

  • Macroscopic: Examining grains
  • Microscopy: KOH prep shows thick hyphae
  • Culture: Sabouraud Dextrose Agar
  microbiology mycetoma
• What is the most common cause of eumycetoma?

  Madurella mycetomatis produces brown-black grains.
  mycology eumycetoma
• What are the grain colors associated with Madurella grisea and Curvularia lunata?

  • Madurella grisea: Brown-black grains
  • Curvularia lunata: Black grains
  mycology fungi
• What are the key features of Actinomycetoma-causing bacteria?

  • Higher filamentous bacteria (Actinomycetes)
  • Painless subcutaneous mass
  • Thin and branching filaments on microscopy
  bacteriology actinomycetoma
• How is Actinomycetoma transmitted?

  Traumatic inoculation via thorn punctures in endemic areas; NOT human-to-human.
  bacteriology transmission
• What is the most common bacterial cause of Actinomycetoma?

  Streptomyces somaliensis produces small, hard yellow/brown 'sandy' grains.
  bacteriology actinomycetoma
• What is a key diagnostic feature of Nocardia brasiliensis?

  Produces yellow, creamy, or orange grains; is acid-fast on ZN stain.
  bacteriology diagnosis
• What is the difference in microscopy between Eumycetoma and Actinomycetoma?

  • Eumycetoma: Thick, segmented hyphae
  • Actinomycetoma: Thin, branching filaments
  mycology bacteriology
• How do Eumycetoma and Actinomycetoma differ in clinical progression?

  • Eumycetoma: Slower progression
  • Actinomycetoma: More aggressive, grows faster
  mycology bacteriology
• How do Eumycetoma and Actinomycetoma differ in response to treatment?

  • Eumycetoma: Responds poorly to antifungals
  • Actinomycetoma: Responds better to antibacterials
  treatment bacteriology