Microbiology Study Guide – Labs 5–9 Terms & Definitions

Flashcards covering key terms, definitions, and concepts from the Microbiology Study Guide.

Incidence

New cases in a defined time period divided by population at risk.

Prevalence

All existing cases in a population at a specific time.

Morbidity

Percentage of infected individuals who develop symptoms.

Mortality

Percentage of total population who die from disease.

Case Fatality Ratio (CFR)

Percentage of diagnosed infected individuals who die.

R0 (Basic Reproduction Number)

Average number of secondary cases caused by one infected person.

Beta Hemolysis

Complete breakdown of RBCs; clear zone on blood agar.

Alpha Hemolysis

Partial breakdown of RBCs; greenish color.

Gamma Hemolysis

No hemolysis; no color change in blood agar.

Selective Media

Media that only allow certain organisms to grow.

Differential Media

Media that show visible differences between organisms.

Catalase Test

Biochemical test that detects catalase enzyme—produces bubbles when positive.

Nipah Virus

Spread primarily through direct contact with infected pigs; reservoir is bats.

Case-control study

Identified behaviors linked to Nipah virus infection, such as handling sick pigs.

Zone of inhibition

Indicates effectiveness of antimicrobial compounds tested against bacteria.

Cinnamaldehyde

Natural antimicrobial that disrupts bacterial membranes.

Gram-negative bacteria

Bacteria selected by MacConkey agar, indicated by pink color for lactose fermentation.

Staphylococcus aureus

Identified by yellow coloration on Mannitol Salt Agar indicating mannitol fermentation.

Catalase-positive

Indicates Staphylococcus species; produces bubbles when tested.