Practice Test Geeks(CMLA) Certified Medical Laboratory Assistant Practice Test
← All CMLA Flashcard Decks

Microbiology Basics Flashcards

7 cards from real CMLA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Microbiology Basics flashcards as text

  1. The coagulase test is used primarily to identify which pathogen?

    Answer: Staphylococcus aureus

    Staphylococcus aureus is coagulase-positive, clotting plasma by converting fibrinogen to fibrin, which distinguishes it from coagulase-negative staphylococci like S. epidermidis.

  2. Which culture medium is used for the primary isolation of Neisseria gonorrhoeae?

    Answer: Thayer-Martin agar

    Thayer-Martin agar is a modified chocolate agar with antibiotics (VCN: vancomycin, colistin, nystatin) that selectively isolates Neisseria gonorrhoeae from genital specimens.

  3. A spore-forming, Gram-positive rod that causes food poisoning via a heat-stable enterotoxin is:

    Answer: Bacillus cereus

    Bacillus cereus produces a heat-stable emetic toxin associated with reheated rice and a heat-labile diarrheal toxin; it forms spores allowing survival of cooking.

  4. The KOH (potassium hydroxide) preparation is used in microbiology to:

    Answer: Clear debris and visualize fungal elements

    KOH dissolves keratin and cellular debris in skin, nail, or hair samples, allowing fungal hyphae and spores to be seen clearly under microscopy.

  5. Which test confirms that an isolate ferments lactose on MacConkey agar by producing a pink/red colony?

    Answer: The organism is a lactose fermenter producing acid

    MacConkey agar contains lactose and neutral red dye; lactose-fermenting organisms produce acid that turns the pH indicator, making colonies appear pink to red.

  6. Which parasite is transmitted via the fecal-oral route and infects the small intestine, causing malabsorption and greasy stools?

    Answer: Giardia lamblia

    Giardia lamblia cysts are ingested via contaminated water or food, excyst in the small intestine, and cause malabsorption with characteristic greasy, foul-smelling stools.

  7. A disk diffusion test shows no zone of inhibition around an antibiotic disk. This indicates the organism is:

    Answer: Resistant

    No zone of inhibition means the antibiotic did not inhibit bacterial growth around the disk, indicating the organism is resistant to that antibiotic.