Organisms causing cystitis & pyelonephritis

Question 1

Important properties of Proteus species

Answer 1

• 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

Question 2

What are the two species of Proteus?

Answer 2

Proteus vulgaris and Proteus mirabilis

Question 3

Where is Proteus found ?

Answer 3

• human colon

- soil and water

Question 4

What infection does proteus cause?

Answer 4

urinary tract infections , especially in women

• vigorous motility of Proteus organisms may contribute to their ability to invade the urinary tract

Question 5

How proteus form calculus/stones?

Answer 5

It produces urease —-> that hydrolyzes the urea in urine to form ——> ammonia
which raises the pH, producing an alkaline urine—-> stones

Question 6

What do these stones do?

Answer 6

• Obstruct urine flow
• damage urinary epithelium
• and serve as a nidus for recurrent infection by trapping bacteria within the stone