L17- RTI VI Flashcards
list the three ways pneumonia is classified
- area of lung affected: lobar, bronchopneumonia, interstitial
- acquisition: CA, HA, ventilator associated
- causative agent: bacterial, viral, others (fungi)
list the common CA-pneumonia pathogens
- *S. pneumoniae
- *Mycoplasma pneumoniae
- *Chlamyodophila pneumoniae
- Haemophilus influenza
-Respiratory viruses (milder form, stems from URI)
list the common HA-pneumonia pathogens (differentiate by group)
(MDR- multi-drug resistant)
Non-MDR pathogens: *S. pneumoniae, H. influenzae, MSSA (meth. sens. S. aureus); Antibiotic-Sensitive Enterobacterieae: E. coli, *Klebsiella pneumoniae
MDR pathogens: *pseudomonas aeruginosa, MRSA; Anitbiotic Resistant Enterobacteriaceae
list the common causes of ‘typical’ pneumonia
- Strep. pneumoniae
- Klebsiella pneumoniae
- H. influenzae
- Staph. aureus
Clinical features of ‘typical’ pneumonia:
- (1) parts of lung involved
- (2) acute Sxs
- (3) signs of consolidation
1- one lobe affected
2- (acute onset) high fever, pleuritic chest pain, productive cough
3- dullness, vocal fremitus / resonance, egophony, whispered pectoriloquy, bronchial breath sounds
‘typical’ pneumonia:
- (1) list the phases
- (2) what are the diagnostic techiniques
1- i) consolidation, ii) red hepitization, iii) gray hepitization, iv) resolution
2- *CXR, sputum analysis, blood cultures
Strep. pneumoniae, aka (1), and causes the following infections, (2)
1- pneumococcus, diplococcus
2- pneumonia, sinusitis, otitis media
describe the distinguishing S. pneumoniae culture features
- α-hemolysis
- Optochin sensitive
describethe distinguishing S. pyogenes culture
- β-hemolysis (due to Streptolysin S)
- Bacitracin sensitive
- PYR+
(1) is the most common cause of CA-pneumonia. It is normally found in (2) and is transmitted in (3) fashion. Highest incidences are in the (4) season.
1- Strep. pneumoniae
2- nasopharyngeal flora (no animal / environmental reservoir)
3- endogenous OR exogenous person to person thru droplets
4- winter, early spring
S. pneumoniae has ______ as its hallmark symptom
rusty sputum: red-brown colored sputum
list the important virulence factors for S. pneumoniae
- Capsule: anti-phagocytic, evades immune response
- IgA protease
- Pneumolysin (many functions, on another slide)
- Autolysin
- Transformation
list the properties and functions of Pneumolysin found in S. pneumoniae
- inhibits ciliated epithelial cell activity
- *Cytotoxic for alveolar / epithelial cells
- causes inflammation + dec PMN effectiveness
list the pneumococcal pneumonia vaccinations and their indications
Pneumovax 23 (inactivated):
- 23 serotypes of different capsular polysaccharides
- for >65 y/o or smokers or those with certain medical conditions
Prevnar 13 (conjugated):
- 13 serotypes of capsular polysaccharides conjugated to a protein
- children <2y/o, adults >65y/o, or those with certain medical conditions
what is a key change to S. pneumoniae seen over the past few decades
significant inc in penicillin (and antibiotic) resistance (more than any other microbe)
Klebsiella pneumoniae:
- (1) family
- Gram(+/-) (coccus/bacillus) (un-/encapsulated) (non-/motile) (aerobe/anaerobe/facultative) catalase(+/-)
- (3) significance of lactose fermentation clinically
1- enterobacteriaeceae
2- Gram- bacillus, un-encapsulated (v. thick/large polysacharide), non-motile, facultative anaerobe, catalase+
3- it will appear pink on MacConkey’s agar
Klebsiella pneumoniae:
- (1) risks
- can cause (2) and (3) of the lung tissue, in part due to (4) virulence factor
1- alcoholics, DM, COPD, nosocomial infections (ventilators, catheters, etc) 2- necrotization of lung tissue 3- severe, destructive pneumonia (2/3 --> Necrotizing pneumonia) 4- LPS endotoxin
Klebsiella pneumoniae has _____ as its hallmark symptom
red currant jelly sputum: thick, viscous, sticky sputum mixed with blood
- *putrid odor to sputum and breath and in copious amounts in Necrotizing pneumonia
- contains: lots of bacteria, inflammatory cells, necrotic tissue
describe features of Necrotizing pneumonia (include alternate names)
-lung abscess / aspiration pneumonia
Defn: >1 area of lung parenchyma replaced by cavities filled with debris
-most are polymicrobial, including: Klebsiella pneumoniae (primary), S. aureus, anaerobes/microaerophiles from mouth flora
Klebsiella pneumoniae:
- (1) method of transmission
- (2) Fe uptake systems
- (3) and (4) are main immune evasion virulence factors
- (5) are key in initiation of infection
- (6) protein key for bacterial resistance
1- person to person contamination only (not thru air)
2- aerobactin, enterochelin
3- thick polysaccharide capsule, CPS/K Ag
4- LPS, O Ag (prevents phagocytosis, impedes C3b and opsonization)
5- pili / fimbriae –> attachment and biofilm formation
6- carbapenemase => carbapenem resistance
Pseudomonas spp., mainly (1) species, is considered a (2) pathogen found in (3). The most common infection it causes is (4).
1- P. aeruginosa
2- environmental opportunist (people with weak immunity)
3- still fresh water sources (ubiquitous)
4- otitis externa / swimmer’s ear
what people are at highest risk of Pseudomonas aeruginosa
- burn victims
- CF Pts (abnormal mucus obtructs airways => chronic lung infections)
- HA infections
(1) is the most common Pseudomonas infection, mostly in the (2) season and in people with (3) risks.
1- otitis externa
2- summer
3- swimming, trauma, dermatologic conditions
describe the general pathogenesis of an otitis externa infection
- breakdown of skin-cerumen barrier
- -> inflammation of skin
- -> pruritis + obstruction
- -> scratching
- -> cerumen quality/quanity altered
- -> inc pH = warm, alkaline, moist ear canal
- -> microorganism growth
