Respiratory Tract Infection Flashcards
Upper respiratory tract is commonly colonised by which gram-positive bacteria?
GRAM POSITIVE STREPTOCOCCI: alpha and beta hemolytic streptococci, Strep penumonia and Strep pyogenes (respectively.)
GRAM POSITIVE STAPHYLOCOCCI: Staphylococcus aureus
What is the microorganism associated with epiglottitis?
Haemophilus influenza type B (Hib)
How is epiglottitis treated?
Ceftriaxone - a cephalosporin. SEFF-TRIA-ZONE
Tests for epiglottitis?
Blood culture, do not throat swab as patient has a compromised airway due to inflamed epiglottis.
For haemophilus influenzae gram stain would show pink (gram negative.)
Haemophilus influenza type B will also grown on chocolate agar/lysed blood agar.
What is the most commonly encountered organism in exacerbations of COPD?
Moraxella Catarrhalis, gram negative diplococcus
What tests would you do in an acute exacerbation of COPD?
Resp exam: cyanosed, wheeze, crackles
Sputum culture to find out the causative microorganism (infleunce antibiotics)
Sputum purulence - severity?
CXR to rule out pneumonia
Treatment for acute exacerbation of COPD?
Antibiotics -> doxycycline or amoxicillin
Bronchodilator inhalers
Short course of steroids in some cases
Evidence of respiratory failure- oxygen
Cystic fibrosis microbiology
Inefficient clearance and build up of mucus = EVERYTHING
Acute Bronchitis Microbiology
Usually viral origin and usually preceded by an upper respiratory tract infection
What is pertussis?
Whooping cough
acute tracheobronchitis
“cold like” symptoms for two weeks.
Paroxysmal cough is main feature
What is the microbiology of pertussis?
Bordatella pertussis, gram negative coccobacillus
How do you diagnose Pertussis?
Take a nasal swab
Attempt grow bacteria on culture. Bortadella Pertussis (pertussis causative organism) would grow on charcoal blood agar!
Can also perform PCR on nasal swab specimen
Can also perform serology on nasal swab specimen
There are not many organisms that would cause paroxysmal cough!
Treatment for pertussis?
Treat with antibiotics if less than 21 days cough
Macrolides - clarithromycin or erythromycin if pregnant patient.
Most common causative organism of community aquired pneumonia?
Streptococcus pneumoniae (70%)
Diagnosis of community acquired pneumonia?
Purulent sputum
Sputum culture: culture on blood agar depends on organism. E.g. alpha hemolysis for streptococcus pneumoniae
Perform PCR on sputum, should be negative for viruses
Perform Gram stain to deermine type of bacteria, will see lots of pus cells
Check if its legionella pneumonia by looking for the legionella antigen in URINE
CXR Consolidation, alveolar infiltrate and pleural effusion