Lab 0 : Biosafety, General

Vocabulary flashcards covering diagnostic microbiology concepts, biosafety classifications, equipment, diagnostic cycle phases, media types, and biochemical assays from Lecture 1.

Sterilization

The complete elimination of all forms of microbial life.

Disinfection

The elimination of many or all pathogenic microorganisms on inanimate objects, with the exception of bacterial spores.

Chemical Fume Hood

A laboratory enclosure designed to protect the user by removing chemical fumes and aerosols from the work area, lacking HEPA filtration.

Biosafety Cabinet

An enclosed laboratory workstation equipped with HEPA filters designed to protect the user, the specimen, and the environment when handling infectious agents.

Biosafety Level 2 (BSL-2)

A biosafety level assigned to agents associated with human disease, where hazards include percutaneous injury, ingestion, or mucous membrane exposure.

Dispatch

A stabilized bleach product used to disinfect laboratory workbenches before and after lab activities.

Pre-Analytical Phase

The initial phase of the diagnostic cycle involving patient examination, tentative clinical diagnosis, appropriate specimen collection, labeling, and transport.

Analytical Phase

The phase of the diagnostic cycle during which laboratory personnel directly examine specimens, select and inoculate culture media, examine subcultures, and set up definitive identification systems.

Post-Analytical Phase

The final phase of the diagnostic cycle where culture reports are prepared, transmitted to the health care provider, and interpreted to initiate appropriate patient therapy.

3-Phase Streaking

A microbiological technique used to isolate single bacterial colonies on an agar plate, requiring the inoculating loop to be flamed between each phase.

Alpha-Hemolysis

Partial lysis of red blood cells surrounding a bacterial colony on blood agar, producing a green discoloration of the medium.

Beta-Hemolysis

Complete lysis of red blood cells in the agar surrounding a bacterial colony, resulting in a clear zone around the growth.

Gamma-Hemolysis

The absence of hemolysis on blood agar, leaving the red blood cells and medium around the colonies unchanged.

Colony Morphology Characteristics

Physical attributes used to describe isolated bacterial colonies on agar, categorized by form, elevation, and margin.

Nonselective Media

Culture media free of inhibitory substances that allow most clinically relevant bacteria to grow well, such as Blood Agar and Chocolate Agar.

Selective Media

Culture media containing added antibiotics or chemical inhibitors designed to restrict the growth of specific organisms while allowing others to grow.

Differential Media

Culture media supplemented with specific dyes, sugars, or chemicals that generate visually distinct reactions among different bacterial species.

MacConkey Agar

A selective and differential culture medium containing bile salts and crystal violet to inhibit Gram-positive organisms, and neutral red with lactose to differentiate enteric pathogens.

Mannitol-Salts Agar

A selective and differential medium with high NaCl concentration that inhibits Gram-negative and most Gram-positive bacteria, used to grow and differentiate Staphylococcus aureus via mannitol fermentation.

Gram Stain

A differential staining procedure involving fixation, primary staining with crystal violet, iodine treatment, alcohol decolorization, and safranin counterstaining to classify bacteria by cell wall composition.

Oxidase Test

A diagnostic test used to detect the presence of Cytochrome C Oxidase in a bacterial electron transport chain.

Catalase Test

A diagnostic assay used to detect the catalase enzyme, which breaks down hydrogen peroxide ($H_2O_2$) into oxygen ($O_2$) gas and water ($H_2O$).