Lab Midterm Flashcards
Examples of eukaryotic microbes
fungi, algae, and protozoa
Mixture of nutrients in which a microorganism can grown
medium/media
Comes from red algae.
Melts at 100 C
Solidifies at 40 C
agar
medium that has known amounts of chemicals
defined medium
medium that has chemically undefined components such as yeast extract or peptone
complex medium
killing or removal of all living organisms from a medium
sterilization
Sterilization technique for media and glass
Autoclave at 121 degrees C
Sterilization technique for loops and glass
Dry heat: flaming, hot air
Sterilization for heat sensitive liquids like antibiotics
filtration
sterilization for surfaces
Radiation: UV, gamma rays
Sterilization for heat sensitive materials such as ethylene oxide
cold sterilization
occur naturally on or in body, don’t cause infection under normal circumstances
Resident (normal) microbiota/flora
temporary on body, can’t grow on skin because too dry and acidic
Transient flora
hospital acquired infection
Nosocomial infection
number of microorganisms required to establish an infection
infectious dose
a group of genetically identical bacteria, arising from a single cell on an agar plate
colony
Three types of whole colony shape
round, irregular, rhizoid
Three types of margin shape
smooth/entire, lobate, filamentous
three types of elevation
convex, umbonate, flat
Common normal flora
Staphylococcus, Acinetobacter, Propionibacterium
Triclosan
liquid soaps
Triclocarban
bar soaps
antibacterial and anti fungal agents that disrupt the cell membrane synthesis
soaps
What do soaps really do?
gets rid of transient flora
colony characteristics
colony morphology
unwanted organism which has been accidentally introduced into the culture
contaminant
some examples of aseptic technique
washing hands, disinfecting benches, sterilizing inoculating loops
a culture that contains only one kind of microorganism
pure culture
technique for diluting bacteria on agar plates; can be used to isolate bacteria from a mixture
streak plate
Common streak plate mistakes
not flaming between quadrants, not letting the loop cool, going back to the previous quadrant too much/not enough
Colony morphology: off-white, semi translucent, round, smooth, produces a dark colony with a green metallic sheen on EMB plate
Escherichia coli
Colony morphology: white, opaque, and small
Staphylococcus epidermis
makes cells more visible by adding contrast between cells and background
staining
1st step in staining cells, can be made from solid or liquid culture
smear
kills microorganisms and sticks them to slide to allow for easier visualization and staining
heat fixation
a result of staining, allows for visualization of cells
contrast
aqueous or alcohol solution of a single basic dye; highlights entire cells, stains every cell the same
Simple stain
shape of cell, visible only under magnification of microscope
morphology
arrangement of pairs of cocci
diplococcus
arrangement of cocci in random or grape like structures
staphylococcus
chain of cocci or bacilli
streptobacillus/streptococcus
tetrad or cubical packets of cocci
micrococcus
spiral with an axial rod
spirochetes
incomplete spiral
vibrio
irregular or variable shaped cell
pleomorphic
Colony morphology: yellow and opaque, gram positive
Micrococcus luteus