Flashcards in Lower Resp. Micro- Debiel Deck (67):
What is the most common cause of community acquired pneumonia?
Sudden onset of chills, fever, dyspnea, productive cough with purulent sputum, PLEURITIC chest pain, tachypnea, decreased breath sounds with dullness to percussion
Gradual onset of non-productive cough, dyspnea, more prominent extra-pulmonary signs (headache, sore throat, diarrhea)
What are the four common causes of aytpical pneumonia?
Viruses (RSV and Influenza)
What type of pneumonia would intra-alveolar exudate indicate?
What type of pneumonia would diffuse patchy inflammation of interstitial areas/alveolar walls indicate?
Interstitial pneumonia/ Atypical
Usually caused by viruses, mycoplasma, chlamydia, legionella
What is the common causes of post-viral/ secondary?
Pneumonia causes associated with IV drug use
Causes of pneumonia associated with post-viral/ secondary infections
Causes of pneumonia commonly seen in alcoholics?
Causes of pneumonia associated with gross aspiration?
Causes of pneumonia associated with the immunocompromised?
Gram - rods
Most common hospital acquired cause of pneumonia?
Gram - rods
Drug resistant staph aureus
Common cause of pneumonia for neonate (birth-6 weeks)
Group B strep
Most common causes of pneumonia in children (6 weeks - 18 years)
Viruses = RSV
Most common cause of pneumonia in Adults (18-40 years)
Most common cause of pneumonia in adults (40-65 years)
Most common cause of pneumonia in the elderly? (older than 65)
Gram - rods
What is the most common cause of pneumonia in COPD patients? second most common cause?
1: H. Flu
2. M. catarrhalis
Why would you not use a b-lactam antibiotic to kill mycoplasma pneumoniae?
They have no cell wall!!! (does not gram stain!)
What is a complication of pneumonia with a mycoplasma pneumoniae infection?
B-cells may generate a response where autoantibodies react with RBCs = IgM cold agglutinins
A 1-day old infant developed pneumonia. Probable cause? why? how do you treat it?
It is carried in mother's genital tract.
Treat with penicillin G
Gram +, B-hemolytic, bacitracin resistant
Can cause pneumonia, meningitis, and sepsis
Strep. Agalactiae = Group B strep!
What are the three B-hemolytic organisms?
Strep Pyogenes (bacitracin sensitive)
Strep Agalactiae (bacitracin resistant)
Gram + cocci
Gram + cocci
Treatment for Chlamydiae pneumoniae
What is the obligate intracellular parasite that can cause atypical pneumonia common in young adults?
What stain do you need to use to visual intra-cytoplasmic inclusion during a chlamydiae pneumonia infection?
What are the two life-forms of chlamydiae?
Elementary body = infectious, enters cell via endocytosis, then transforms into reticulate body (extracellular)
Reticulate body: replicates by fission, and reorganizes into elementary bodies (intracellular)
What stain do you need to use to visual legionella?
What media do you need to culture legionella on?
Charcoal yeast extract with iron and cysteine
Where does legionella like to proliferate?
They get phagocytosed by alveolar macrophages, and survive and proliferate in there.
Virulence factors of RSV
G-surface protein for attachment
F protein causes infected cells to fuse
At what age group does Strep Pneumonia become the most common cause of pneumonia?
Gram + diplococci
Susceptible to optochin
What causes "rust-colored" sputum?
It does alpha hemolysis (only partially lysis RBCs)
What organism is associated with alcoholics and aspiration and shows up bright red because it is gamma hemolytic?
What kind of agar do you grow H. influenzae on?
If someone has conjunctivitis and it feels like "grains of sand" what are you thinking?
Multinucleated giant cells in pneumonia, crusted lesion on lip. What are you thinking?
What antibody opsonizes microorganisms once they arrive in the alveoli?
Does bronchitis cause inflammation in the alveoli?
Peak age for bronchiolitis?
When are adults infectious with influenza?
The day before symptoms begin through 5 days after onset of illness
Describe bordatella pertusis.
Gram - cocco-bacillus
With what bug do you see an increase in lymphocytes (rather than a typical increase in neutrophils with bacterial infection)?
What drug is given in pertussis?
Tx for Moraxella catarrhalis?
How does B. pertussis adhere to cilia?
Describe the pathogenesis of B. pertussis.
Binds epithelium via Filamentous hemagluttinin
AB toxin inactivates Gi proteins. This leads to an increase in cAMP.
Increase in cAMP impairs phagocytosis
Describe what happens from the B cell response to Mycoplasma pneumoniae.
B cells generate IgM antibodies that react with erythrocytes. *Cold agglutination*
Pneumonia or abscesses.
3 things that cause green sputum?
How can you differentiate between bronchitis and pneumonia?
Bronchitis will NOT have consolidations or infiltrates as seen in pneumonia
Most common cause of bronchiolitis?
Which antigenic types of flu cause the epidemics?
Type A and B!
Type C is mild disease, rarely causes epidemic, and by age 15 almost everyone has developed antibodies to it
What is one way to distinguish influenza infection from the common cold?
Common cold is afebrile
Influenza has abrupt onset high fever
Who should get a flu vaccine?
Everyone over 6 months of age
What does B. Pertussis need to be grown on?
When is someone with the flu infectious?
1 day BEFORE symptoms begin through 5 days after onset of illness
Describe the difference between antigenic drift and shift
Antigenic Drift: occurs when minor changes in antigens occur due to gene mutaiton in influenza virus
Antigenic Shift: occurs when MAJOR changes in antigens occur due to gene reassortment in influenza A virus
Which type of influenza virus undergoes antigenic shift?
Type A influenza virus
Which organism causes rust colored sputum?
Strep pneumonia due to the alpha hemolysis
Which organisms cause green sputum?
Which organism produces red currant jelly sputum?