ENT DSA I Checkpoint Flashcards
- Anatomically, why are children more susceptible to ear infections than adults?
a. Horizontal Eustachian tube and shorter
- Why are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis the most common causes of acute otitis media? Hint: Location
a. Nasopharynx normal flora
- Distinguish between acute otitis media and otitis media with effusion. Which symptoms would you use to tell them apart? Which typically requires antibiotics and which does not?
a. AOM = antibiotics, OME = no antibiotics, pain fever discharge
- What are the guidelines for treating otitis media provided by the CDC? When should observation be considered (age group) and when would antibiotic therapy be considered?
a. = 2yr known- antibiotic severe, observations nonsevere; unknown- observation
- For otitis externa, how would you visually distinguish between a fungal infection and a bacterial infection? What kind of morphology would you look for?
a. Appearance of colonies
- Which two genera of fungi are the most common causes of otomycosis? Which type of environment is particularly conductive for infection?
a. Aspergillus and candida, damp (such as water from swimming stuck in canal)
- What is the taxonomy of Moraxella catarrhalis?
a. Nonmotile, gram-negative, aerobic, oxidase+, cocci
- Which disease is Moraxella catarrhalis commonly associated with? Which diseases are Moraxella catarrhalis associated with in immunocompromised patients or patients with decreased lung function (COPD, chronic asthma, long-term smokers, etc.)?
a. Most common, AOM
b. Also sinusitis, bronchitis, and pneumonia in immunocompromised
- What two characteristics distinguish between Moraxella and Neisseria?
a. Carb fermentation, DNase positive for M. catarrhalis
- What is the taxonomy of Corynebacterium diphtheriae?
a. Gram+, facultative anaerobic, non-spore-forming rods
- How is the pharyngitis caused by C. diphtheriae unique in appearance?
a. Gray plaques
- What is the mechanism of diphtheria toxin and which systems does it affect?
a. Inhibits elongation factor 2 (essential for protein synthesis)
b. A subunit blocks protein synthesis, and B subunit allows access to neural and cardiac tissue
- What is the agar C. diphtheriae grows well on?
a. Loeffler’s medium or potassium tellurite agar(appears black)
- Describe the initial treatment of diphtheria.
a. Antitoxin given immediately
- Upon Gram staining, how do Actinomyces species appear?
a. Gram+ rod-shaped bacteria, sometimes confused with fungi due to appearance
b. Looking like sulfur-granules
