Microbiology-Actinomycetes

What bacterium causes actinomycosis?

Actinomyces israelii

This bacterium causes dental caries, gingivitis and peridontitis

Actinomyces viscosus

This bacterium causes cat-scratch disease

Bartonella henselae

Name 3 symptoms of actinomycosis

Cervicofacial, jaw and lung abscesses, sinus tracts and inflammation from IUDs

This symptom occurs in cat-scratch disease

Chronic lymph node swelling

What aspect of actinomycetes is fungus-like?

Difficulty of treating infections

This bacterium displays "corrosive" growth on agar

Eikenella corrodens

This bacterium is present in the human mouth and spreads by direct contact

Eikenella corrodens

T/F: Actinomyces israelii is acid-fast

F

T/F: Actinomycetomas are surface lesions on the skin

F (deep tissue sinus tract extensions)

What is the most major risk factor for nocardiosis?

Immunocompromise (also steroid use and bacterial inhalation/entry through damaged tissue)

This bacterium is ubiquitous in water, rubber, pipes and plastics

Legionella pneumophila

How is cat-scratch disease diagnosed?

Microscopic viewing of tissue sections

This bacterium causes nocardiosis

Nocardia asteroides

What 3 symptoms occur in nocardiosis?

Nodular abscesses, sinus tracts and actinomycetomas

What two characteristics cause actinomycetes to be characterized as "more bacterial than fungal"?

Penicillin-susceptible and prokaryotic cell wall

How is actinomycosis diagnosed?

"Sulfur" granules in pus and immunofluorescence

These 3 methods are used to diagnose Legionella infections

Sputum culture, direct fluorescent antibody test and radioimmunoassay

What actinomycete is a major source of antibiotics for topical antibiotic creams?

Streptomyces

How is nocardiosis treated?

Surgical debridement and cotrimazole or sulfadiazene

How is actinomycosis treated?

Surgical debridement and penicillin G or trimethoprim/sulfamethoxazole

T/F: Actinomycetes are filamentous soil bacteria

T

T/F: Recovery from systemic nocardiosis is poor

T

Name 4 symptoms of an infected human bite wound

Sinusitis, brain abscess, pneumonia and endocarditis