Microbiology and Specimen Collection Flashcards

What is the maximum time a urine specimen should sit at room temperature before culture without preservative?

Answer: 2 hours

Unrefrigerated urine should be cultured within 2 hours to prevent bacterial overgrowth that distorts colony counts.

Which organism is the most common cause of community-acquired urinary tract infections?

Answer: Escherichia coli

E. coli, a gram-negative gut bacterium, causes the majority of uncomplicated UTIs.

Why should specimens be properly labeled at the patient's bedside?

Answer: To prevent misidentification and ensure results match the correct patient

Labeling at the bedside immediately after collection prevents specimen mix-ups and patient misidentification.

Which precaution is essential when handling all patient specimens?

Answer: Standard (universal) precautions treating all specimens as infectious

Standard precautions require treating every specimen as potentially infectious regardless of the patient's diagnosis.

A sputum specimen for culture is best collected at what time?

Answer: First thing in the morning before eating

Early morning sputum contains accumulated overnight secretions, providing the best yield for culture.

What does a CLIA waived test mean for a medical assistant's scope?

Answer: Simple tests with low risk of error that the MA may perform

CLIA-waived tests are simple, low-complexity tests that medical assistants are permitted to perform in the office.

How should a specimen be transported if there will be a delay before processing for most bacterial cultures?

Answer: Refrigerated, unless contraindicated for the specific test

Refrigeration slows bacterial overgrowth for most cultures, though some specimens (like CSF and certain swabs) require different handling.