Chapter 3.1 Flashcards
The Five I’s
-Inoculation
-Incubation
-Isolation
-Inspection
-Identification
Inoculation
Introduction of microbes into or upon a media
Culture
-(verb) Adding to and the growing of microbes in various media
-(Noun) Population of microbes in or on nutrient medium
Medium/Media (plural)
A nutrient-containing environment in which microbes can multiply
Incubation
Inoculated media placed in temp controlled chamber called incubators
Incubator temperatures and function
-Control temperature for culture growth.
-Temps ranging from 20-45 degrees C
-Also control atmospheric gasses ( oxygen, CO2)
Microbial growth in liquid medium is
Cloudy or has turbidity
Colonies
Visible masses of piled up cells
Media classified into 3 properties
1) Physical state 2) Chemical Composition 3) Functional type
Media Physical state
Liquid, semisolid, solid
Media Chemical composition
Chemically defined (synthetic) or Complex (not chemically defined)
Media Functional types (8)
-General purpose
-Enriched
-Selective
-Differential
-Anaerobic growth
-Specimen transport
-Assay
-Enumeration
Liquid Media
-Water based solutions that do not solidify above freezing temps
-Broths, milks, infusions
Semisolid media
-Clot like consistency at room temps
-Contains enough agar or gelatin to thicken but not solidify
-Used to determine motility of bacteria
-Also used to localize a reaction to specific site
Brain and heart infusion
- made by boiling cow or pig heart and brain. Very nutrient dense
semisolid- lower concentration of agar (0.5-1%)
Solid Media
-Provides a firm surface upon which cells can form discrete/separate colonies
-Used to isolate bacteria and fungi
Agar media
-Complex polysaccharide isolated from red alga
-Solid at room temp, liquefies at 100 C
-Begins to solidify at 42 C
-Any medium containing 1-5% agar usually has the word “agar” in its name
Defined (synthetic) Media
-Exact chemical compositions are known
-May contain pure organic and inorganic compounds that vary little from one source to another
Complex Media
-Contains at least one component that is not chemically definable.
-Provides rich mix of nutrients for microbes that have complex needs
examples: Blood, serum, meat extracts,milk, yeast extract, soybean
Fastidious bacteria
Have complex or specific growth requirements
General purpose media
-Complex media w/ nutrients that grow a broad spectrum of microbes
-Nutrient agar and broth, brain heart infusion, and soy agar
Enriched media
-Contains complex organic substances that fastidious bacteria require for growth.
(blood, serum, hemoglobin or special growth factors)
Selective media
-Contains one or more agents that inhibit growth of certain microbes.
-Encourages select microbes to grow
-Primary isolation of a certain type of microorganism from a mixed sample
Differential Media
-Allow multiple types of organisms to grow but display visible differences between species
(size, color, media color changes or formation of gas bubbles or precipitates)
Blood Agra
-Differential AND enriched media
-used as an enrichment medium for fastidious microbes as well as differential for seeing visible differences
Hemolysins
Enzymes that (break down) red blood cells to release iron-rich hemoglobin
Beta- hemolysis
-Complete lysis of red blood cells
-Transperency
Alpha- hemolysis
incomplete lysis of red blood cells
Gamma hemolysis
no hemolysis
MacConkey Media
-Selective for gram negative bacteria
-Lactose fermenters grow red whereas non-fermenters grow yellow
Mannitol Salt Agar
-Selective for staphylocci
- Mannitol fermenters turn medium yellow.
-nonfermenter growth turns pink
Reducing Media
Grow anaerobic bacteria
Carbohydrate fermentation media
-Contain sugars that can be fermented and pH indicator to show reaction
Transport media
Maintains and preserves specimen
Assay Media
-Tests effectiveness of antimicrobial drugs disinfectants, antiseptics, cosmetics and preservatives on the growth of microorganisms
Enumeration
-Used in industrial and environmental microbiology to count the numbers of organisms in milk, water, food, soil etc
Isolation
Individual bacterial cell separated and given space on a firm nutrient surface.
Colony
-Mound of cells formed on solid nutrient surface.
-Arises from a single cell
Isolation techniques
-Streak plate method
-Pour Plate Method
-Spread Plate Method
Pure culture/Anexic
Container of medium that contains only a single known species or type of microorganism
Subculture
A second level culture from a well isolated colony
Mixed culture
Container that holds two or more identified, easily differentiated species of microbes.
Contaminated culture
A culture that was once pure or mixed that now contains contaminants (unwanted microbes)
Inspection
-Examining growth and location of growth in tubes
-Looking at morphology of cells or colonies (size, shape, color)
Identification
Identifying celluar geneses, species and metabolism through
-Biochemical testing
-Genotypic testing (DNA)
-Immunological testing
Biochemical testing
Determines chemical characteristics such as nutrient requirements, products given off during growth, presence of enzymes, and mechanisms for deriving energy.
Genotypic testing
Analysis of DNA-PCR sequencing
Immunologic testing
Testing against known antibodies
