Exam 1 Flashcards
gram positive
All Staphylococci species, Streptococci species and Bacillus subtilis
gram negative
E. coli, Acintobacter faecails, Klebsiella pneumoniae
fastidious organisms
All Streptococcus species.
organisms that tolerate 7.5% salt
All Staph species and Bacillus species.
goal of glove uses
prevent exposure of the worker to potentially harmful organisms, and prevent contaimination of the work with normal flora from the workers of from organisms from the environment
gloves should be put on in a manner that one does not
introduce organisms to the surface of the gloves
gloves should be removed in such a manner that one does not contaminate ones self with
the very organisms for which the gloves were preventing exposure
dispose of used gloves in the
biohazard waste disposal
in procedure 1.1 we touched our gloved hand to the agar plate, then we touched our hair, face and cultures to the plate. What was the point of touching just the gloved hand before we touched anything else to the plate.
this was the control
in exercise 1.2 we conducted a experiment using live organisms but before that we swabbed our clean gloves on a plate and after the experiment we put our gloves on the plate. What was the point of this exercise.
to see the bacteria that was on our hands prior and compare it to the amount of bacteria that grew on the after plate, this showed that even if we do not touch the bacteria some can still get on ourselves through the air.
resolution
measure of clarity of an image. measure of the shortest distance between 2 objects
parfocal
the ability of a microscope to retain coarse adjustment focus when changing objectives
total magnification
magnification is the amount by which the image one views is enlarged. total magnification of the object viewed is the magnification available through the objective lens multiplied by the magnification of by the oculars
oculars magnify how much
10x
if viewing through the 40x how much is the total magnification
400x
low objective
first objective used when viewing a slide
low objective number
10x
high dry objective
used to obtain higher magnification
high dry objective number
40x
you can view protozoa and fungi through
40x
you must use what when using 100x lens
immersion oil
you can see bacteria with what objective
100x
sepsis
presence of microbial life
aseptic technique
protocol that ensures cultures do not travel to the outside world
colony
group of genetically identical cells grouped on solid or semisolid matrix in a large enough mass that is visible to the naked eye
inoculating needle
handle with a long straight piece of wire made from metal
inoculating loop
tool has a handle with a long piece of wire that has been bent at the end to form a loop
sterile cotton swabs
used to transfer organisms from the original source to a growth medium, or to transfer a culture from one medium to another
loops and stabs are incinerated to
kill any organisms on them immediately prior to use
after you transfer bacteria with a loop or stab you incinerate it again, why?
to prevent culture organisms from entering the environment
thermophile
grows best above 45 degrees Celsius
mesophile
growth range is 10-47 degrees Celsius with an optimal range of 25-35 degrees Celsius
psychrophile
growth range of -5-20 degrees Celsius with an optimal range from -5-5 degrees Celsius
psychrotroph
able to grow as low as 0-5 degrees Celsius but may grow at higher temps with a maximum temp often well above 20 degrees Celsius
majority of human pathogens are
mesophile
aerobic
grows only in the presence of oxygen
anaerobic
cannot survive in the presence of oxygen and grows only in its absence
facultative anaerobe
prefers anaerobic but can survive in either the presence or absence of oxygen
facultative aerobe
prefers aerobic conditions but can survive in either the presence or absence of oxygen
facultative
can survive aerobic or anaerobic, inconclusive on what it prefers
microaerophilic
prefers lower than ambient air oxygen level and a higher CO2 lever but not a strict anaerobic condition
ambient air incubation
is the air found in our environment, incubating in ambient air means simply placing the culture in the room or incubator as is
microaerophilic incubation
a candle jar is created by placing a candle on top of the cultures, lighting it, and closing it with a tight seal. as the candle burns down, O2 is depleted, raising the % CO2 to the proper level
anaerobic incubation
contain no O2. obtained by fixing the O2 in ambient air with H2 and creating water
ambient air incubation were placed on
the normal rack
microaerophillic incubation were placed in
jar
anaerobic incubation were placed in
container
energy source
energy can be obtained from light or from chemical bonds
phototroph
obtain energy from light
chemotroph
obtain energy from chemical bonds
most organisms that cause human disease are
chemotroph
carbon source
carbon is needed to build organic moleules necessary for life. generally provided in the form of a carb, but some bacteria can obtain carbon from other organic moleules. some organisms can obtain from CO2 as it is fixed into organisms moleules to store energy from sunlight
nitrogen source
through some bacteria can use inorganic nitrogen most bacteria require an organic nitrogen source. organic nitrogen can be found in protiens, amino acids and other organic compounds
inorganic salts
often present in media, salts provide cofactors for enzymatic reactions and other purposes, excess salt can inhibit growth
vitamins
many bacteria require specific vitamins for growth. others can manufacture vitamins. humans rely on this feature for some of their own vitamin needs
free water
water is essential for life. bacteria require a minimum level of available water for growth
defined media
contains a specific and precise amount of ingredients. One knows exactly how much of a particulate sugar or amino acid is present
minimal media
contains bare minimum of nutrients required, often limiting the amount or variety available for purposes of study
general media
contains all the basic needs for most organisms
enriched media
contains a vast variety and amounts of nutrients, giving organisms the best chance of growth
2 commonly used standard methods to isolate pure cultures
pour plate method, streak plate method
most common used method of isolation
streak plate
semiquantitation
quadrant in which isolated colonies occur is dependent on the concentration of initial inoculation
first stage of idenfication
colony morphology, cellular morphology, gram reaction of the organisms
biochemical testing
refers to testing an organism for the ability to preform a single biochemical reaction or a battery of specific biochemical reactions
color
use terms like white, creamy, yellow, red, gray
size
described in milimeter, average diameter across an isolated colony
density
describes the ability of light to pass through the colony
transparent
one can see through it when it is held up to the light
opaque
solid, not able to see through
shape
describes the shape of the entire colony, use terms like round, pinpoint, filamanous or irregular
margin
describes the shape of the edge of the colony use terms like, smooth, wavy, irregular, woolly
elevation
describes the colony as viewed from the side, use terms like raised, flat, convex, hilly, pitted or craterform
consistency
describes the texture of the colony
turbidity
degree of cloudiness
0 turbidity
one can see clearly through the broth; one is able to clearly read print through the broth
1 turbidity
hazy, the broth has a slight haze; letters appear out of focus when read through broth
2 turbidity
cloudy, it is difficult to see through the broth; letters cannot be distinguished though one can tell they exist
3 turbidity
turbid, the broth is so cloudy one cannot see through it
cellular morphology
refers to the size, shape and arrangement of the bacterial cells
cellular shape
coccus, bacillus, spirillum
coccus
spherical in shape
bacillus
rod shaped, elongated, shaped like a stick or rod
spirillum
long and coiled
