Pneumonia Flashcards
What are typical vs atypical bacteria causes of pneumonia
Typical
- S. pneumo, H. influ, Staph. Aureus, GAS, M. cat, aerobic gram-negative bacteria (Acinobacteria)
Atypical (not severe, can still walk)
- legionella (gram-neg)
- Mycoplasma pneumo
- Chlamydia pneumo
What are characteristics of S. pneumo
Gram?
Shape?
Hemolytic?
Capsule?
- Gram-positive
- Cocci in pairs/short chains
- Alpha-hemolytic
- Polysaccharide capsules (virulent serotypes only)
Which bacteria is one of the most important causes of pneumo?
Staph aureus especially MRSA
H. influ characteristics?
Gram?
Shape?
Capsule that causes pneumo?
Requires?
- Gram-negative
- coccobacilli
- non-typeable h. influ causes penumonia
Klebsiella pneumonia characteristics
Family?
Gram?
Found where?
Who it affects?
Symptoms?
Lactose fermenter?
Capsule?
Family? Enterobacteriacae
Gram? Negative
Found where? Normal flora, mouth, skin
Who it affects? diabetes, alcoholism (people with debillating diseases)
Symptoms?
- alveoli destruction –> thick/bloody sputum
Lactose fermenter?
- Yes
Capsule: yes
Pseudomonas aeruginosa
Gram?
Who does it affect?
Shape?
Virulence factors?
- Gram-negative
- Opportunistic pathogen
- Shape: Rod-shpaed (bacillus)
- Virulence factors (BAPE PO)
Biofilm formation from exopolysaccharide
Pili
Endotoxin
Legionella Pneumophilia
Gram?
Aerobic/anaerobic?
Environment
Fastidious?
Disease?
Gram? Negative
Aerobic/anaerobic? Anaerobic
Environment? Needs w/ iron L-cysteine
Fastidious
- Pontiac fever
Mycoplasma pneumoniae
Shape, cell type?
Symptom?
Virulence?
Biggest organism? T/F
Shape, cell type?
- no cell wall
- pleomorphic cells (can change shape)
Symptom?
- “walking pneumo”
Virulence?
- specific adhesion protein
Biggest organism? F
- smallest organism that can be free living in nature and self-replicating
Chlamydophila pneumoniae
Cell wall characteristics? (4)
Shape it forms?
STD?
Disease it caused?
Symptoms?
How does it reproduce?
Cell wall characteristics?
- high lipid content
- rigid, no peptidoglycan (but contains the genes to make it)
- plays role in cell division
- Has lipopolysaccharide LPS
Shape?
- form elementary bodies –> infectious, resistant
STD? NO
Diseases it caused?
- bronchitis, pneumonia, sinusitis
Symptoms? Malaise, cough
How does it reproduce?
- must infect another cell (obligate intracellular pathogen)
What are major risk for opportunistic pneumonia (3)
- AIDS
- long-term corticosteroid
- Anything that suppresses the immune system
Mycobacterium tuberculosis characteristics
Aerobic/anaerobic?
Spore/non-spore forming
Cell wall characteristic?
Affects who?
Symptoms?
Aerobic/anaerobic?
- Aerobic
Spore/non-spore forming
- Non-spre forming
Cell wall characteristic?
- ACID FAST: cell wall that has a lot of lipid called mycolic acids
Affects who?
- immunocompromised NOT healthy people
Symptoms?
- Coughing, chest pain, weakness, weight loss
What is the staining technique for M. tuberculosis and acid-fast bacteroa? What are the steps?
Ziehl-Neelsen technique
1. Apply primary stain of carbolfuschin for 30 seconds
2. Heat fix cells to the slide using flame
3. Decolorize with acid alcohol for 15-20 seconds
4. Apply counterstain of methylene blue for 30 seconds then rinse excess stain
which pathogens are NOT likely in children in community acquired pneumonia? and NOT atypicals?
M. catt
staph auerus
Atypicals?
legionella
which pathogens are NOT likely in adults in community acquired pneumonia? and NOT atypicals?
staph auerus
Atypical?
legionella
When does hosptial-acquired pneumo develop HAP?
48+ hrs after hosptial admission
When does ventilator-acquired pneumo develop VAP?
after 48-72 hrs after intubation
When does healthcare-associated pneumo develop HCAP? (3)
Must have all the following
- hospitalized for 2+ days within the last 90 days
- Resided in nursing or LTC
- In last 30 days, received IV antibiotic, chemotherapy or wound care>
which bacterias are the leading cause of HAP VAP & HCAP (3)
- gram-negative aerobic bacilli (acinobacteria)
- Staph aureus esp. MRSA
- Multidrug resistant pathogens
What are challenges for lab diagnosis of CAP
Hard to narrow the pathogen of CAP to 1 microbe
Is CAP causative agents required for outpatients? What are indications for extensive diagnosting tests? (2)
No
Indication
- if the result of the diagnostic test is likely to change individual antibiotic management
- to detect reportable infections or ones that may lead to outbreak
Who is blood culture tests indicated for? (3)
- Patients with host factors that make it DIFFICULT TO CLEAR BACTEREMIA
- Patients who require hospitaliztion due to moderate or severe bacterial CAP
- Children who fail to show improvement
What are advantages of blood culture (3)? What are limitations?
Adv
- Specific daignosis
- Increased potential to affect antibiotic management
- Provide data on causative agent
Limitations
- cant detect mycoplamsa pneumo and viral causes
- False negatives
- If had prior antibiotic therapy = less positive results
- False positives: due to contamination of blood culture
What presence of sputum suggests heavy contamination from saliva in the sputum sample?
Presence of many squamous epithelial cells/low-power field (10+ cells, 100x field)
What suggests a purulent exudate in a sputum sample?
A large number of polymorphonuclear leukocytes (25+)
