BASIC - LAB 2 Flashcards
define sterilization
process that KILLS all viable micro-organisms
what is the process that REDUCES the number of viable microorganisms
disinfection
what materials are used for disinfection
chlorine, glutaraldehyde, and alcohol - 70% isopropul
t or f all materials must be washed and cleaned before serilization and disinfection
t
why are preservatives added to pharmaceutical preparations
to prevent microbial growth during the manufacturing process and storage
USP chapter ___ defines preservative and describes the procedure for testing antimicrobial effectiveness for various product categories
51
_____ selectively interfere with the growth of microorganisms while ideally causing little or no damage to the host and used to treat susceptibe infections
abx
why are antibiotic sensitivity tests important
because not all abx are appropriate to use for all infections
abx sensitivity testing allows
to choose the appropriate abx for an infection and to detect resistant strains
the lowest concentration that inhibits microbial growth is known as
minimum inhibitory concentration
the ____ is used to test the sensitivity of the causative bacteria to several abx
kirby bauer sensitivity test
explain how the kirby bauer sensitivity test works
a disc is saturated with mic of a abx and placed on a bacterial plate
the sensitivity of the bacteria is determined based on the measured zone of growth inhibition
what is the universal first step for classifying bacteria
the gram stain
which type of bacteria has a thick peptidoglycan layer in their cell wall and retain the primary crystal stain - APPEAR VIOLET
gram POSITIVE
what are the characteristics of gram NEGATIVE bacteria
higher lipid content, appear PINK due to restaining with safranin
what are examples of basal media
tryptic soy agar and nutrient media
what are characteristics of basal media
they contain basic nutrients required for bacterial growth
what is enriched media
adding blood, vitamins and other nutritional components to basal meia for FASTIDOUS ORGANISM
define fastidious
means that the organism has a specific nutrient requirement for growth that is not present in basal media
define differential media
contains additional components used to differentiate between microorganisms
what are used in media to distinguish between lactose fermenters adn non fermenters
lactose and pH indicators
______ in the presence of pH indicator is used to distinguish between staph aureus and other staphylococci
mannitol fermentation
selective media contains components that _____ growth of some microorganisms but not others
suppresses
___ and ____ are used for the selective growth of gram negative bacteria
crystal violet , bile salts
high concentration of _______ is used for selective staphylococci growth
sodium chloride
what are considered selective-differential media?
mannitol salt agar and macconkey agar
what selective differential media is used to detext H2S bacteria like shigella and salmonella
hektoen enteric agar
what are some methods of sterilization?
heat (autoclaving), filtration, radiation
when is sterilization an appropriate method of bacterial control?
contact with sterile body fluids, surgery, and injection
when is disinfection an appropriate method of bacterial control?
prevent contaminiation, person to person, prevent baterial transfer, can’t completely kill
antibiotics are used to ____ microbial growth
prevent and limit
why must antimicrobial effectiveness be demonstrated in multi dose formulations
multidose exposed to antibacterial growth more than a single dose
how many categories are there for abx product effectiveness?
4
what is the product description for category 1
injections, other parenterals including emulsions, otic products, sterile nasal products, and opthalmic products made with aqueous bases or vehicles
what is the product description for category 2
topically used products made with aqueous bases or vehicles , nonsterile nasal products, and emulsions including those applied to mucous membranes
what is the product descriptio for category 3
oral products other than anatacids made with aqueous bases or vehicles
what is the product description for category 4
antacids made with an aqueous base
what are the three major bacterial classifications
spore formation, biochemical reactions and serological reactions
which bacterial are spherical shaped
staphylococci, streptococci, nesseria
which bacteria are rod shaped
bacilli
gram positive bacteria are what color under staining
violet
gram negative bacteria stain what color
red
what kind of bacteria do not stain
mycobacteria
why don’t acid fast bacteria stain
they have mycolic acid in the outer layer, waxy and can’t retain stain
how can we get myco bacteria to retain stain
pre treatment with heat or detergent before they will accept a stain
what color do acid fast bacteria appear because they resist decolorization
red
what are the steps and elements used in gram staining
crystal violent
iodine
decolorizer like alcohol
safranin - counter stain
obligate aerobes ____ oxygen for energy production
need
what is an example of an obligate aerobe
mycobacterium tb
obligate anaerobes ____ grow at atomospheric oxygen concentrations
cannot
what are examples of the obligate anaerobes
bacteroides, clostridium
what are examples of facultative anaerobes
staphylococcus, streptococcus, e coli
certain bacteria have a ___ for special media such as sucross, lactor or mannitol
requirement
nutrient broth/agar are used for
routine cultivation of microorganisms
t or f all strains of bacteria grow well in nutrient broth and agar
false, some strains may grow poorly or fail to grow
blood agar detects
hemolytic activity
chocolate agar detects
haemophilus influenza
____ bacteria have a complex nutritional requirement and only grow when provided with specific nutrients
fastidious
what bacteria utilizes mannitol
staphylococci aureus
what bacteria is used for detect e coli and enterobacteria
lactose
___ detect pH change as a result of fermentation of carbohydrates
pH indicators
____ is utilized by H2s producing bacteria such as enterobacteria, clostridia
sodium thiosulfate
___ contains components that suppress growth of some bacteria but not others
selective media
______ prevents the growth of gram positive bacteria
crystal violet
bile salts prevent the growth of _____ bacteria
positive
_____ prevent the growth of gram negative bacteria
high sodium chloride concentrations
antibiotics prevents the growth of
susceptible bacteria
the zone of inhibition si when there is
no bacterial growth
