Pneumonia syndromes

Question 1

Causes of community acquired pneumonia

Answer 1

• Strep pneumonia
• Haemophilus influenzae
• Morexella catarrhalis
• Staph aureus
• Legionella pneumophila
• Enterobactericeae (Klebsiella pneumoniae) and Pseudomonas
• Mycoplasma pneumoniae
• Chlamydia
• Coxiella burnettii
• Viruses: RSV, parainfluenza virus, human metapneumovirus (children), influenza A and B (adults), adenovirus (military recruits)

Question 2

Causes of health care associated pneumonia

Answer 2

• Staph aureus, methicillin sensitive
• staph auerus, methicillin resistant
• Pseudomonas aeruginosa
• Strep pneumoniae

Question 3

Causes of hospital acquired pneumonia

Answer 3

• Gram neg rods, Enterobacteriaceae (Klebsiella, serratia marcescens, E coli) and pseudomonas
• Staph aureus (usually methicillin resistant)

Question 4

Causes of aspiration pneumonia

Answer 4

-Anaerobic oral flora (Bacteriodes, Prevotella, Fusobacterium, Peptostreptococcus) admixed w/aerobic bacteria (strep pneumonia, staph aureus, Haemophilus influenzae, Pseudomonas aeruginosa)

Question 5

Causes of chronic pneumonia

Answer 5

• Nocardia
• Actinomyces
• Granulomatous: Mycobacterium TB and atypical mycobacteria (Histoplasma capsulatum, coccidiodes immitis, Blastomyces dermatitidis)

Question 6

Causes of necrotizing pneumonia and Lung abscess

Answer 6

• Anaerobic bacteria (extremely common) with or without mixed aerobic infection
• Staph aureus, Klebsiella pneumoniae, Strep pyogenes, and type 3 pneumococcus (uncommon)

Question 7

Pneumonia in the immunocompromised host

Answer 7

• Cytomegalovirus
• Pneumocystis jiroveci
• Mycobacterium avium–intracellulare
• Invasive aspergillosis
• Invasive candidiasis
• Usual bacterial, viral, and fungal organisms