Lecture 2: Pneumonias and Respiratory Infections Flashcards
What are the 2 major bacteria that will grow on chocolate agar (factors V and X)?
- Haemophilus influenza
- Neisseria
Mycoplasma pneumoniae requires growth on a media containing what?
Cholesterol and Nucleic acids (purines and pyrimidines)
What is the number one cause of bronchitis and atypical pneumonia in teenagers and young adults?
Mycoplasma pneumoniae
What is the appearance of Mycoplasma pneumonia when grow on cultured media?
Dome-shaped colonies with “fried egg” appearance or “mullberry” appearance
Why is microcytic anemia associated with Mycoplasma pneumoniae?
- Cold agglutinins
- Pts develop monoclonal IgM ab’s directed at a common RBC Ag called the “I” Ag, which appears to be modified w/ infection
Labs drawn from person with pneumonia showing hyponatremia and hypophosphatemia is consistent with what organism?
Legionella
Which 2 bacterial causes of pneumonia are associated with positive urinary antigens?
- S. pneumoniae
- Legionella
What are 3 Abx options for Mycoplasma pneumoniae?
- Macrolides
- Tetracyclines
- Fluoroquinolones
Emperic abx for community acquired pneumonia requires minimum of how many days of tx?
5 days
For the emperic tx of commuity acquired pneumonia what is first drug you should consider using in an ambulatory patient; what if they can’t tolerate this first lin drug?
- Macrolide = 1st
- Can’t tolerate –> go with Doxycycline
For the emperic tx of commuity acquired pneumonia what are 2 options for pt at increased risk for drug resistance (Abx in past 90 days, immunosuppression, exposure to kids)?
- Fluoroquinolone
- Macrolide + beta-lactam
For the emperic tx of commuity acquired pneumonia what should you give to hospitalized pt?
Fluoroquinolone
For the emperic tx of commuity acquired pneumonia what should you give to pt in ICU?
Fluoroquinolone + antipneumococcal beta lactam (3rd gen. Ceph or ampicillin sulbactam)
What Abx should be added to regimen for pneumonia if coverage for pseudomonas is desired?
Piperacillin-tazobactam, cefipime, or a “penem”
What are the 3 etiologic agents most often causing atypical pneumonia?
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- Legionella pneumophilia
Chlamydia pneumoniae presents similar to M. pneumoniae, but what is one part of the presentation that may be a clue?
Pt may have hoarse voice w/ Chlamydia pneumoniae
Who is most often affected by atypical pneumonia and how does it present?
- Younger adults
- Generally “milder” sx’s –> fever + chills + cough (may be dry) + dyspnea
- Typically follows URI like sx’s: rhinitis, laryngitis, pharyngitis, sinusitis
What lab can be ordered to aid in differentiating between viral and bacterial pneumonia?
Procalcitonin –> will be elevated in bacterial pneumonia
What is CURB-65 severity score for whether you should admit someone or discharge pt with pneumonia; what scores are necessary?
- Confusion
- BUN >20 mg/dL;
- RR >30;
- BP (systolic <90 or diastolic <60)
- Age ≥65 y/o
*Each worth 1 point –> 0-1 = outpatient; 2 = moderate/severe - short hospitalization; 3-5 = severe pneumonia/ICU
Which bacterial cause of pneumonia has a life cycle consisting of an elementary body and a initital body (aka reticulate body)?
Chlamydia pneumoniae
What is the gram stain, morphology, and oxygen dependence of Legionella?
Gram negative rod (pleomorphic), aerobic, flagellate, water lover
Legionella is a facultative intracellular parasite for what?
Amoebas
Which bacterial cause of pneumonia is associated with a fever with pulse-temperature dissociation (high fever, low HR), severe HA, confusion, myalgia and cough?
Legionella
Which 3 abx can be used for tx of Legionella?
- Azithromycin
- Levofloxacin
- Doxycycline
Which characteristic finding does Klebsiella pneumoniae produce on CXR?
Bulging fissure sign
Which bacteria forms colonies like the ones seen on the right?
Klebsiella pneumoniae —> Mucoid colonies
Which bacterial cause of pneumonia is associated with bullous myringitis?
Mycoplasma pneumoniae
Who gets the pneumococcal vaccine?
- Age ≥65
- Immunocompromised
- Asplenic pt’s
- Pt’s 2-64 y/o w/ risk factors
What is the morphology of adenovirus?
Non-enveloped, dsDNA, icosahedral virus
What is this CXR indicative of?
Aspiration pneumonia; notice you cannot see the R heart border
What is a common finding on a CXR in pt with Histoplasmosis?
“Coin lesions” = calcified pulmonary nodule
Which skin lesions may be seen in a small percentage of patients with Coccidioides immitis?
Erythema NODOSUM
What are the signs/sx’s and labs/imaging associated with Hantavirus infection?
- High fevers + myalgias + cough + N/V
- Progresses to pulmonary edema + respiratory failure
- Thrombocytopenia + leukocytosis + ↑ LDH,
- Bilateral pulmonary infiltrates
What is the reservoir for Chlamydophila psittaci and how is it transmitted?
- Reservoir = birds and poultry
- Trasmitted via inhalation of bird feather dust or dried out bird feces
Using the mnemonic Some Killer Have Pretty Nice Capsules; what are the encapsulated bacteria?
- S. pneumoniae
- Klebsilla
- H. influenzae
- P. aeruginosa
- N. meningitidis
- Cryptococcus
To be nosocomial pneumonia the patient will have to have at least 2 out of what 3 sign/sx’s in the presence of a new or progressing pulmonary opacity on CXR?
- Fever
- Leukocytosis
- Purulent sputum
What type of pneumonia is this?
Interstitial pneumonia
