Microbiology Lecture Review Flashcards

A set of 30 practice flashcards based on microbiology lab quiz topics including biochemical tests, microscopy, antibiotics, and helminthology.

What conclusion can be made from a coagulase broth incubated at $37^{\circ}C$ for $36$ hours showing positive results?

Coagulase is produced

True or False: A VP positive organism undergoes a $2,3\text{-butanediol}$ fermentation.

True

What is the limit of resolution for a microscope using the $40\times$ objective ($0.65$ numerical aperture) at $500\,nm$?

$$384.6\,nm$$

To what class of helminth does the organism described in slide 4 belong?

Cestode

What is the route of transmission for the organism identified in slide 5?

Vector borne via Reduviid bug

True or False: Taxo A (bacitracin) is used to differentiate and presumptively identify Group A strep (Streptococcus pyogenes).

True

What conclusion can be made about an organism on a Novobiocin plate if it produces catalase enzyme?

Staphylococcus spp; susceptible

What is the enzyme produced in a positive Bile Esculin Hydrolysis test?

Esculinase

True or False: The spontaneous oxidation reaction in the oxidase test only occurs after the $20$ second waiting period.

False

True or False: PEA medium contains a differential substrate.

False

What conclusion can be made about an organism on an HEA plate incubated for $24$ hours at $37^{\circ}C$ showing fermentation?

Probable Gram negative organism; Lactose/Sucrose/Salicin fermenter

What organism is presumptively identified (P-ID) on an HEA plate showing blue/green growth without fermentation?

Shigella spp

What organism is presumptively identified (P-ID) on an HEA plate showing black precipitate?

Salmonella spp

True or False: The production of a single bubble in the catalase test is a positive result.

True

What is the conclusion for a bacterium on an MSA plate showing yellow growth?

Halotolerant organism and mannitol fermenter; Staphylococcus aureus

What is the Mechanism of Action (MOA) for the antibiotic Tetracycline?

Inhibits protein synthesis

What is the Mechanism of Action (MOA) for the antibiotic Penicillin?

Inhibits cell wall synthesis

True or False: Penicillium species reproduce asexually by conidiospores.

True

To what phylum does the organism identified in slide 19 belong?

Mastigophora

What conclusion should be made for a citrate slant incubated for only $18$ hours?

Inconclusive because the test was not incubated long enough

What is the observation and result for a Phenol Red broth test showing a yellow broth with no bubble?

$$A/-$$

What are the observation and result for a positive Urease test?

pink and positive

What type of leukocyte is identified in the slide 23 image?

Neutrophil

Which of the following is NOT a function of a lymphocyte: Produce antibodies, Phagocytosis, or Attack cells infected with viruses?

Phagocytosis

What is the conclusion for an organism on a MAC plate showing pink/red growth?

Organism is a gram negative, lactose fermenter

Which ingredient in a medium, such as Peptic digest of soybean meal, would make it undefined?

Peptic digest of soybean meal

What is the Mechanism of Action (MOA) for Nalidixic Acid in the CNA Agar plate?

Inhibit DNA synthesis

What is the conclusion for a bacterium on a CNA agar plate showing a clear zone of clearing?

Probable Gram-positive, beta hemolytic organism

What is the conclusion for a bacterium on a CNA agar plate showing greening of the medium?

Probable Gram-positive, alpha hemolytic organism

True or False: The bacterium on a CNA agar plate showing no change in the medium is a gamma hemolytic organism.

True