Pure Culture Techniques and Isolation of Bacteria

Vocabulary flashcards covering key concepts related to pure culture techniques and the isolation of bacteria.

Culture

Multiplying microbial organisms by letting them reproduce in a predetermined culture media under controlled laboratory conditions.

Pure Culture

A culture containing a single type of organism.

Agar

Solid media used for culturing microorganisms.

Broth

Liquid media used for culturing microorganisms.

Selective Media

Media that promotes growth of some bacteria while limiting the growth of others.

Differential Media

Media that distinguishes between different bacteria based on changes in colonies or media.

All Purpose/Supportive Media

Contains nutrients that support the growth of a wide variety of microorganisms.

Enrichment Media

Media that enhances the growth of less abundant microorganisms using selective conditions.

Tryptic Soy Agar (TSA)

All purpose/supportive media.

Eosin Methylene Blue (EMB)

Selective and differential media for isolating gram-negative organisms.

Spread Plate Method

A method where the original culture is serially diluted and spread on the surface of an agar plate to grow surface colonies.

Pour Plate Method

A method where the original culture is serially diluted and mixed with molten agar to grow surface and subsurface colonies.

Streak Plate Method

A method where the original culture is diluted across an agar surface using an inoculating loop.

Serial Dilution

A stepwise dilution of a liquid culture in which the dilution factor at each step is constant.

Colony

A single cell or grouped related cells that produce a visible mass.

Streak Plate Purpose

To obtain a pure culture for identification and testing.

Simmons Citrate Agar

A differential medium that tests for the utilization of citrate as a carbon source.

Bromothymol Blue

A pH indicator that changes from green to blue in alkaline conditions.

Catalase Test

A biochemical test that detects the presence of the enzyme catalase by the rapid formation of bubbles when hydrogen peroxide is added.

Coagulase Test

A biochemical test used to differentiate Staphylococcus aureus as positive for coagulase.

Phenol Red

A pH indicator used in Urea Agar; changes from yellow to fuchsia in alkaline conditions.

Group A Streptococcus

Includes S. pyogenes that is beta-hemolytic and sensitive to bacitracin.

Superbug

Bacteria resistant to three or more different types of antimicrobial agents.

Epidemiology

The study of the spread of disease and the causes and effects in defined populations.