Organisms causing cystitis & pyelonephritis Flashcards
1
Q
Important properties of Proteus species
A
- Gram negative rods
- Produces phenylalanine deaminase ( distinguish it from other Enterobacteriaceae)
- Produces urease ( cleaves urea to form NH3 and CO2)
- Some are motile & produce a striking swarming effect on blood agar
Characterized by expanding rings (waves) of organisms over the surface of the agar
2
Q
What are the two species of Proteus?
A
Proteus vulgaris and Proteus mirabilis
3
Q
Where is Proteus found ?
A
- human colon
- soil and water
4
Q
What infection does proteus cause?
A
urinary tract infections , especially in women
- vigorous motility of Proteus organisms may contribute to their ability to invade the urinary tract
5
Q
How proteus form calculus/stones?
A
It produces urease —-> that hydrolyzes the urea in urine to form ——> ammonia
which raises the pH, producing an alkaline urine—-> stones
6
Q
What do these stones do?
A
- Obstruct urine flow
- damage urinary epithelium
- and serve as a nidus for recurrent infection by trapping bacteria within the stone
