Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
8 Cards in this Set
- Front
- Back
|
Epidemiology
|
Found in soil, plants, moist environments, fresh vegetables; hospitals (ICU - nosocomial)
High mortality - not because of bacteria, because it is infection of debilitated hosts |
|
|
1) gram stain
2) morphology 3) metabolism 4) appearance |
gram negative bacillus
obligate aerobe except w/ nitrate no carb. fermentation oxidase positive blueish-green |
|
|
Predisposing factors
|
Disease of debilitated
prolonged hospitalization (ICU) cystic fibrosis surgery, trauma, burns immunosuppression |
|
|
Colonization
|
Normally found - oral, nasal mucosa, skin, stool
Only needs moist environment - adaptable, spreads easily Damaged tissue vulnerable |
|
|
Virulence Factors
|
Endotoxin (antiphag), pili, flagella, glycocalyx (capsule)
Exotoxin A (inhibits protein synthesis) Exoenzyme S (inhibits protein synthesis) Elastase (dissolves lamina propria) Pyoverdin (scavenges Fe) Pyocyanin (produces reaction O2 species) Alkaline protease (corneal, alveolar necrosis) |
|
|
Exotoxin A
|
most toxic VF - 20,000x more than endotoxin
Inhibits protein synthesis --> necrosis |
|
|
Clinical Manifestations - Community-acquired
|
Cutaneous - paronychia, toe web infection, pyoderma, cellulitis, vasculitis, burn/sepsis
Otitis externa Malignant - cartilage (diabetics, elderly - significant mortality) Ulcerative keratitis (extended wear contact lenses, trauma) Whirlpool folliculitis (hot tubs, on trunk under bathing suit - apocrine sweat glands) Bone/joint infection - sternocalvicular, sneaker osteomyelitis (puncture) Endocarditis (IV drug users) Pulmonary infection in CF |
|
|
Clinical Manifestations - Hospital-acquired
|
Pneumonia
Bacteremia (ICU, burns, AIDS) Neutropenic cancer pts - big 4 = E. coli, Klebsiella, Pseudomonas, S. aureus GI infection - typhilitis Shanghai fever |
