Lab Practical 1 Flashcards
What is a colony derived from?
A single cell
What is a cfu?
Colony forming unit
Describe a bacterial colony that would be indicative of coming from the surfact of people
- Small to medium in size
- white, off-white, or yellow in color
Describe bacterial colonies that originate from water
glistening/shiny in appearance
Describe bacterial colonies that originate from soil
rough appearance, not shiny
Which of the treatments would be considered the most effective at sanitizing hand?
Soap and water followed byb hand sanitizer
What are the 3 components of ACC’s Hazard communication system?
- communication from your instructor
- material safety data sheets (MSDS)
- Hazard labels
What are the required PPE for lab?
- Z87 approved safety eyewear
- gloves
- shoes that cover all of foot
- lab apron
- tie back long hair
What type of information does a typical chemical hazard label portray?
- category of the hazard (Health - blue, flammability - red, reactivity - yellow, personal protection -white)
- Level of Hazard (0 = no hazard, 4 = extremely hazardous)
Know the difference between a biohazard and radioactive materials label image
What are 4 tools used for aseptic technique?
- incenerator
- bunsen burner
- inoculating loop
- inoculating needle
What is a term that described cloudy growth in a broth?
Turbidity
What is a semisolid media?
- also referred to as motility media
- assessed whether an organism is mobile or not based on where growth occurs - growth only at site of inoculation is immobile while growth outside of that is considered mobile
- uses stick and poke method
What is a solid slant media and what is it used for?
- solid medium that provies larger surface area to grow microorganisms
What is a media solid plate?
- Used as an agar plate, and provides the largest surface area for microbial growth
What is aseptic technique?
- uses practices and procedures to prevent contamination from microorganisms
- minimizes risk of exogenous contamination that may lead to infection in a healthcare setting
What are the different growth patterns that can occur in broth?
- control - no growth
- turbid - general cloudyness throughout
- pellicle - bacteria floating on top of the broth
- sediment - bacteria that sinks to bottom
- flecculent growth - bacteria that grows in clumps
What is the purpose of streaking a plate for isolation?
- to produce isolated colonies of an organism on an agar plate
- can be used to seperate organisms in a mixed culture of when you need to study colony morphology of an organism
What are the 5 conditions that fluid thioglycolate broth/medium (FTM) provides?
- aerobic
- anaerobic
- facultative
- microaerophil
- aerotolerant
What does fluid thioglycollate medium test for?
- it tests the aerotolerance of bacteria
- uses methylene blue indicator which shows color in the presence of oxygen
What is the purpose of an anaerobic jar?
- creates an enviornment where there is no molecular oxygen available for cellular respiration
- a catalyzed reaction creates water in the form of condensation on the inside of the jar
- methylene blue is used as an indicator - turns blue in presence of oxygen but is colorless in an anaerobic enviornment
What are the different types of flagellar arrangements?
- atrichous - no flagella
- monotrichous - one flagella
- amphitrichous - flagella on either end
- peritrichous - all over surface
- lophotrichous - tuft of flagella (like a tail)
What are the 3 different ways that can determine is a bacterium is motile?
- wet mount
- motility media
- flagellar stain
How does the flagella stain work?
- provides a method for viewing bacterial flagella by employing crystal violet in an alcoholic solution as a primary stain
- Alchol evaporates leaving the stain around the flagella
What is the mortant used for flagella?
Tannic acid
What is the primary purpose of simple stains?
The simple stain is used to discern morphology - cell shape, size, and arrangement
What are the stains typically used for simple stains?
- methylene blue
- safranin
- crystal violet
Are simple stains basic or acidic?
- basic - the cell wall of bacteria are acidic so they react and accept the basic stain
- can cause some distortion from the reaction
Are negative stains basic or acidic?
- Acidic - the dye is repelled by the cell wall of bacteria, but it stains the background instead
- bacteria show up more clearly, no distortion
- takes longer to dry
What is the primary dye used for negative stains?
nigrosin
What is the catalase test?
- used to differentiate staphylococci (catalase-positve) from steptococci (catalase-negative)
- catalase is an enzyme produced by bacteria that respire using oxygen, and it protects them from the toxic by products of oxygen metabolism
What is the gram stain?
a staining method that differentiates bacterial species into two groups: gram-positive and gram-negative
What is the primary stain used for the gram stain?
crystal violet
what is the secondary stain used in the gram stain?
Safranin
What is the mortant used in the gram stain?
Iodine
What is the decolorizer used in the gram stain?
Ethanol or acetone
What is an endospore stain?
it will display the presence or absence of endospores which can be used to identify specifc gram-positive bacteria in Bacillus of Clostridium
What stains are used in the endospore stain?
- Mahcalite green - colors the endospores
- safranin - acts as counterstain, stains vegetative cells
- water - used as decolorizer
What us an acid fast stain?
A differential stain used to identify acid-fast organisms
How are acid-fast organisms characterized?
by their wax-like nearly impermeable cell walls that contain mycolic acid
What stains are used in an acid-fast stain?
- carbol fuchsin - stains acid fast as pink
- acid-alcohol - used as decolorizer
- methylene blue - counterstain which stains non acid-fast organisms blue
What is an example of a diagnostic test that uses acid-fast?
Mycobacterium tuberculosis
What is a capsule stain?
- method devised to observe bacterial capsules
- mixes india ink which stains the background providing a negative background to view cells and capsules
- utilizes an acidic dye for background and basic dye to stain the cell purple
What types of stains are used in the capsule stain?
A mixture of india ink (acidic background) and crystal violet (basic cell wall)
