Let’s see how well you can connect the organism, media, and laboratory findings. 🔬 🧪 Question 1 A wound culture contains a mixture of Gram-positive and Gram-negative organisms. The technologist wants to selectively recover Gram-positive organisms while suppressing many Gram-negative bacteria. Which medium would be MOST appropriate? A) CNA agar B) Chocolate agar C) CDC anaerobe blood agar D) Egg Yolk Agar 🧪 Question 2 A stool specimen from a hospitalized patient with antibiotic-associated diarrhea is submitted for anaerobic culture. The physician suspects Clostridioides difficile. Which selective and differential medium is classically associated with recovery of this organism? A) Mannitol Salt Agar B) CCFA C) Bile Esculin Agar D) Tinsdale Agar 🧪 Question 3 A beta-hemolytic organism is recovered on blood agar. The technologist knows that blood agar alone cannot provide a definitive identification. Which statement BEST explains the role of blood agar in this situation? A) Beta hemolysis definitively identifies S. pyogenes B) Hemolysis provides a differential characteristic that must be interpreted with additional tests C) Blood agar selectively inhibits Gram-negative organisms D) Any beta-hemolytic Gram-positive organism is S. agalactiae 🧪 Question 4 A respiratory specimen contains heavy mixed flora. The technologist wants a medium that inhibits many Gram-negative organisms and favors recovery of Gram-positive bacteria. The laboratory specifically uses a medium containing phenylethyl alcohol. Which medium is being described? A) PEA agar B) CNA agar C) CCFA D) MSA 🧪 Question 5 An anaerobic culture is being set up from a deep tissue specimen. The technologist wants an enriched, nonselective blood-containing medium designed to support the recovery of a broad range of anaerobic organisms. Which medium is MOST appropriate? A) Tinsdale Agar B) Mannitol Salt Agar C) CDC Anaerobe Blood Agar D) Bile Esculin Agar 👀 How many can you get right without checking your notes?