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
arrangment
diplo, chaining, tetrad, clusters, palisade, random
diplo
appers in pairs
chaining
form a chain
tetrad
cells tend to group in fours
clusters
cells clump in an irregular fashion forming grape like clusters
palisade
picket fence arrangement
random
no regular arrangment
bacilli cannot _______ ever
cluster
when prepping a slide from a broth you do not need to add
water to the slide
simple stain
ascertain the cellular shape and arrangement of the bacteria being studied
methylene blue
blue
safranin
pink/red
most common differential stain
gram stain
gram postive color
purple
gram negative color
pink
primary stain of gram
crystal violet
mordant
substance which aids the cells ability to hold a stain
gram counter stain
safranin
how to report a gram stain
gram reaction (positive or negative), cell shape (bacillus, cocci, spirillum) and then cell arrangement (chain, cluster, tetrad, loosely arranged)
differential stain is designed to
enhance visualizing unique morphology as well as obtain additional information that is helpful in differentiating between species
differential stain is based on
structural or physiologic differences between groups of bacteria
differential step
the procedural step in the process that determines the identifying difference between two groups of bacteria
differential step in gram stain
decolorization
report for spore stain
no spores seen, terminal/subterminal/central spore seen
spore formers are more difficult to
kill
primary stain in spore
malachite green
differential step in spore
rinse
counter stain in spore
safranin
primary stain/differential step in capsule
india ink
in capsule stain the India ink is a
negative stain
counter stain for capsule
crystal violet
fluorescence antibody stain determines if a specific _____ is present
antigen
lophotricous and polar
flagella at one end with multiple flagella
monotricous and polar
one flagella at one end
peritrichous
multiple flagella all over cell
amphitrouous and polar
flagella at both ends
acid fast screen for what bacteria
myobacterioum sp. and nocardia sp.
acid fast do not
gram stain
capsule
state capsule is present or not present
spore
state positive for spore formation or negative for spore formation
acid fast
state acid fast or non acid fast
flagella stain
state flagella present or flagella not present, where flagella are present state arrangement
general purpose media
designed to permit growth of most organisms.
nutritive (enriched) agar
designed to permit growth of fastidious organisms as well as organisms that grow well on general purpose media.
selective media
enhances the ability to isolate an organism by providing the adequate growth requirements for the group of organisms being selected while inhibiting the growth of an alternate group or not
differential media
designed to visualize a difference in some ability of two groups of organisms and narrow down the possibilities in an identification process
TSA classification
general/ not differential
TSA
most organisms grow well on TSA
NUT agar classification
not differential
NUT agar
more nutrients than TSA and is basically NUT broth with agar added to form a semisolid media, some fastidious organisms survive on NUT agar
blood agar classification
nutritive and differential
BA is based on the organisms ability to hemolyze
RBC
MacConkey Agar classifcation
selective and differential
macconkey is selective for
gram negative
Macconkey is differential based on the ability of the organism to ferment
lactose as a energy source
mannitol salt classification
selective and differential
mannitol is selective for
7.5% salt tolerant organisms
mannitol is differential based on an organisms ability to ferment
manitol
eosin methylene blue classification
selective and differential
EMB is selective for
gram negative
EMB is differential between
lactose feremeters
arm
area of microscope between tube and base.
base
Bottom support structure of microscope
coarse focus
Larger of the two adjustment knobs, this moves the objective lenses closer or farther away. Large steps
fine focus
Smaller of the two adjustment knobs, moves objective lenses closer or farther away in small steps. Can be used to fine tune focus after using the course focus
condenser lens
Mounted in or below the stage. This focuses the light on the specimen. Helps increase illumination and resolution.
diaphragm
Most useful at higher powers. 5 hole disc housed under the stage adjusts the amount of light passing through the stage opening.
eyepiece lens
AKA ocular lenses. What you actually look through.
field of view/field of vision
Diameter of light visible when looking into the eyepiece. Increasing lens power equals smaller FOV
illuminator
light source, Mounted underneath the stage.
nose piece
Hold the objective lens.
objective lens
Lens closest to the object being viewed. Each one has different magnification, 4x, 10x, 40x, 100x.
4x
scanning lens
10x
low power
40x
high dry power
100x
oil immersion
immersion oil
Special oil used at 100x or higher. Drop of oil is placed on the cover slip with the objective lens lowered until it touches the oil. Acts as a bridge between the glass lens and the glass slide. Oil concentrates the path of light to increase the resolution of the
Image.
mechanical stage/stage
Main flat stage that holds the specimen.
stage clip
On the stage that clip the specimen down
on/off switch
Controls the power to the microscope.
parfocal
Maintains focus on the specimen when objective lens is switched
resolution
Lens system ability to resolve fine details of the observed object.
staphylococcus epidermis GS
gram pos cocci
staphylococcus epidermis fast
no
staphylococcus epidermis 7.5% salt tolerant
no
staphylococcus epidermis other characteristics
mannitol nonfermenter, usually nonhemolytic
staphylococcus aureus GS
gram pos cocci
staphylococcus aureus fast
no
staphylococcus aureus 7.5% salt tolerant
yes
staphylococcus aureus other characterisitcs
mannitol fermenter usually
beta or nonhemolytic
streptococcus pneumoniae GS
gram pos cocci
streptococcus pneumoniae fast
yes
streptococcus pneumoniae 7.5% salt tolerant
no
streptococcus pneumoniae other characteristics
alpha hemolytic fastidious
bacillus subtillis GS
gram pos bacillis
bacillus subtillis fast
no
bacillus subtillis 7.5% salt tolerant
yes
bacillus subtillis other characteristics
spore former
escherichia coli GS
gram neg bacillus
escherichia coli fast
no
escherichia coli 7.5% salt tolerant
no
escherichia coli other characteristics
lactose fermenter
acinetobacter faecalis GS
gram neg bacillus
acinetobacter faecalis fast
no
acinetobacter faecalis 7.5% salt tolerant
no
acinetobacter faecalis other characteristics
lactose nonfermenter
klebsiella pneumoniae GS
gram neg bacillus
klebsiella pneumoniae fast
no
klebsiella pneumoniae 7.5% salt tolerant
no
klebsiella pneumoniae other characterisitics
lactose fermenter
capsule former
mucoid colony morphology when forming capsules
what species is fastidious
streptococcus pneumoniae
what species is 7.5% salt tolerant
staphylococcus epidermis, staphylococcus aureus, bacillus subtillis
ubiquitous
reside in almost every naturally occurring environment
universal protocal
policy followed in the medical professions requiring that one must treat every patient and every biological sample as if they carry a potential pathogen
opportunistic pathogens
can cause disease in the right circumstances
what lab type are we in
BSL2
after switching from high dry or oil lenses one only adjusts the
fine focus
only adjust coarse focus when in
low power
basic steps in the process of identification of bacteria strains
isolation of strain
determination of colony morphology
determination of cellular morphology and gram stain
you can confidently confirm a species after doing the basic steps by
biochemical testing
antigen determination
molecular techniques
cellular morphology refers to the
size shape and arrangement of cells
goal of a smear
adhere to a glass slide a single layer of bacterial cells for viewing
direct smear
term used in clinical settings to refer to a stain preformed directly on a clinical specimen
how do we know if a carb test is positive
positive means a change in color to yellow, negative stays the pink color with no color change
urease positive and negative
positive is bright pink and negative is no color change
positive and negative citrate color
positive is a deep blue and negative is no color change (green color)
sulfur test positive and negative
positive is black color where there is growth and negative is no black color
positive and negative indole
positive is when the kovacs reagent changes color into a red ring and negative is no red ring
