Download microbio 62 [4-20

Chapter 62
Respiratory System Infection Learning Objectives
1.
Causes of pharyngitis, most common => least common:
 Group A streptococci (S. pyogenes)
 Microbes causing nasopharyngitis (see below)
 EBV
 Enteroviruses
i. Cause herpangia (vesicles on mucous membranes of the throat)
2.
Causes of nasopharyngitis, most common => least common:
 Rhinovirus
 Coronavirus
 Respiratory syncytial virus (RSV), parainfluenza, adenoviruses
3.
Causes of Epiglottitis:
 Haemophilus influenzae
i. just HATES children (osteomyelitis, pneumonia in infants, meningitis too??)
4.
Who is affected by epiglottitis?
 Children who are not immunized against influenza B are most at risk for epiglottitis
 Adults can get it but it isn’t dangerous. They will culture S. pneumoniae instead.
5.
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
Causes of Croup:
Parainfluenza virus
Other viruses or Staphylococcus aureus
6.
Causes of acute tracheobronchitis (no order):
 Mycoplasma pneumoniae, Chlamydophila pneumoniae (atypical pneumonia strains),
Bordetella pertussis, and some viruses
7.
What is a bacterial infection superimposed on chronic bronchitis called?
 Acute Exacerbation of Chronic Bronchitis (AECB)
8.
What are the defense mechanisms of the lungs?
 Mucus as part of the mucocilliary escalator, containing:
i. Lysozyme
ii. Lactoferrin
iii. IgA antibodies
9.
What are the typical causes of Community-Acquired Pneumonia?
S. pneumoniae and other gram-negative bacteria (e.g. K. pneumoniae) are the “typical
organisms”
 S. pneumoniae tends to affect those who already have COPD

10. What gram-negative bacteria are nursing home residents at an increased risk for contracting?
 Pseudomonas aeruginosa and S. aureus
11. Let’s go through the list of atypical causes of Community-Acquired Pneumonia!
 Psittacosis
parrot fever
 Q Fever
due to Coxiella burnetti
 Histoplasmosis
soil and bats
 Coccidioidomycosis
soil
 Cryptococcosis
soil and pigeons
 Legionarre Disease
lurks in bad water
 Mycoplasma pneumoniae & Chlamydophila pneumoniae
12. How does acute pneumonia present on radiographs?
 Infiltrate (shadow) on X-Rays is most important for diagnosis of pneumonia
 Focal lobar consolidation with typicals S. pneumoniae, K. pneumoniae, and aspirations
 Diffuse interstitial infiltrates with atypicals M. pneumoniae, C. pneumoniae, and P. jirovecii
 Cavitation with S. aureus and Mycobacterium tuberculosis
13. What special symptoms appear in Hospital-Acquired Pneumonia? What bacteria cause it? What
about in severe infections?
 Tachycardia and tachypnea appear along with the classic cough, fever, purulent sputum,
shortness of breath, and pleuritic chest pain in HAP
 Caused by gram-negative rods (e.g. K. pneumoniae, E. coli) and S. aureus
 More severe infections are caused by P. aeruginosa and Acinetobacter species
14. What is another way to say subacute pneumonia?
 Lung abcesses, usually from normal mouth bacteria gone awry
i. Usually caused by gross aspiration into the lungs
15. Aside from the normal bacteria, what other microbes can cause subacute pneumonia?
 The soil-dwelling fungi that are listed above in “Community Acquired Pneumonia,” causing:
Histoplasmosis, Coccidioidomycosis, Cryptococcosis
16. What bacteria affects immunocompromised patients?
 Pneumocystis jirovecii
 Aspergillus fumigatus and CMV are also possibilities