CLT Microbiology & Urinalysis Flashcards
6 cards from real CLT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CLT Microbiology & Urinalysis flashcards as text
Waxy casts found in urine sediment are associated with which clinical condition?
Answer: Severe chronic renal failure
Waxy casts form from the degeneration of granular casts in nephrons with very slow urine flow and indicate severe chronic renal disease.
A urine dipstick is positive for nitrites. What does this finding indicate?
Answer: The presence of nitrite-reducing bacteria (gram-negative organisms)
Many gram-negative bacteria reduce dietary nitrates to nitrites; a positive nitrite result on dipstick suggests a bacterial UTI caused by gram-negative organisms.
Which agar is used for the isolation of Neisseria gonorrhoeae and other fastidious organisms?
Answer: Thayer-Martin agar
Thayer-Martin agar is an enriched selective medium containing antibiotics (VCN — vancomycin, colistin, nystatin) that inhibit normal flora while supporting growth of Neisseria species.
In urine microscopy, which finding is most associated with acute glomerulonephritis?
Answer: RBC casts
RBC casts indicate that red blood cells have leaked through damaged glomeruli and formed casts in the tubules, which is pathognomonic for glomerulonephritis.
The coagulase test is used to differentiate which two clinically important Staphylococcus species?
Answer: S. aureus (positive) from S. epidermidis (negative)
Coagulase production distinguishes the pathogenic S. aureus (coagulase-positive) from coagulase-negative staphylococci such as S. epidermidis.
When a urine specimen for culture cannot be processed within 2 hours, what is the recommended storage condition?
Answer: Refrigeration at 2–8°C for up to 24 hours
Refrigeration at 2–8°C preserves urine specimens for culture for up to 24 hours by inhibiting bacterial growth without altering colony counts.