Lab Exam 1 Review

this refers to practices that minimize the chance of transfer of microorganisms between a patient and a health care worker

aseptic technique

this term refers to infections acquired while in a health care facility

nosocomial

the pores on most masks used in the health care setting will block droplets and large dust particles but are usually not small enough to block a virus that is not associated with a droplet or dust particle

true

for those working in extremely dangerous conditions the use of this PPE will give them the greatest chance of being protected from air borne pathogens

PAPR

this refers to hospital rooms that are set up so that the air from the hallway flows into the room rather than having the air flow out of the room into the hallway

negative pressure rooms

which is the proper order for donning PPE?

gown → mask → face shield → gloves

when properly doffing contaminated gloves, this should be done with the first glove that is removed

it should be wadded up and placed in the palm of the still gloved hand

a patient has a runny bowel movement that spills on the floor.  You are to properly clean and disinfect the floor.  Once you have your PPE on, this is the first thing you should do

physically remove as much organic matter as possible

a skin pathogen is shown to be transmitted via direct contact or contact with surfaces touched by an infected person.  What measures must be taken to reduce the risk of transmission?

Based off of CDC Principles, step one is cleaning. Physically (through wiping or scrubbing) removing the microorganisms is just as important as the cleaning agents that will be used. The second step is disinfecting. Allowing the disinfect to be on the contaminated surface for as long as the time it says it should be on the label of the disinfect being used. 

washing hands before and after putting gloves on is good practice as well

what role do surfactants play in cleaning surfaces? 

prevents the organic material from attaching onto the surface. they will interfere with the forces that allow the organic material to stick onto the surface, by doing this it is easier to clean up as well

how many points can be deducted from your final point total for rule violations?

10 points

what happens if you come to lab late?

cannot take quiz and could be barred from participating in lab exercises

where do unnecessary items go?

lockers, shelves, or underneath the back bench in the lab

what are not allowed in the lab?

cellphones, food, or drinks

what is proper apparel for lab?

• long sleeves must not be worn (roll sleeves up if worn)

• if you have long hair, it must be tied back or covered in a hair net

• no open-toed shoes or open-back shoes

• no exposed skin between the pants and shoes

the following procedure must be done when entering lab

• place nonessential items in the lockers, shelves or beneath back bench

• wash lab bench with lysol disinfectant

• wash hands

what needs to be done before leaving lab?

• equipment must be returned to the place of origin

• the clean up checklist must be done

• gas bench is turned off

• trash is disposed of

• chairs are pushed back to the bench

what are considered microbes?

too small to be seen with the naked eye

what are the current recognized domains of life?

bacteria, archaea and eukarya

archae

• extremophiles (can live in harsh environments)

• smaller than average bacteria

• prokaryotic

• can be found in minor part of normal flora of the mouth and colon

bacteria

• most numerous in the planet

• important roles in the nutrient cycles

• most have cell walls

• peptidoglycan

• prokaryotic

fungi

• multicellular

• eukaryotic

• cell wall made of chitin

• saprophytic (secrete enzymes that secrete proteins)

virus

• do not make ATP

• not considered alive

• cannot replicate themselves without entering a cell and utilizing the biochemical machinery of a host cell

ubiquity

found everywhere

volume of sphere

4/3(3.14)r³

relative volume

volume of first cell (or virus)/volume of second cell (or virus)

how do you aseptically transfer liquid using an inoculating loop?

• flame the loop until wire turns red and let cool

• remove top of sterile water

• flame opening of the tube

• dip inoculating tube into the water and remove a loop of water

• flame the tube opening and replace the top

how do you aseptically transfer a measured volume of liquid from one sterile container to another using a serological pipette?

• leave pipette in the sterile sleeve until ready for use

• open the tube of water and flame the tube opening

• draw the water to the “0” mark

• flame the tube opening and replace the top

• flame opening of your tube when finished putting the liquid into it and replace top

how do you create a fungal garden?

• acquire agar plate and write name

• find dust covered surface

• open plate and place it where you blow the dust from the surface to land onto the plate

• give one short puff of breath

• close plate and incubate at room temp for several weeks

how do you safety transport a microscope?

lift using two hands, one on the base and one on the arm and make sure cord is wrapped around base before lifting

how do you clean the microscope?

clean stage, objectives and oculars with lens paper and cleaning solution

how should the microscope be left when finished working with it?

• remove slide from the stage and dispose of properly

• move mechanical stage to its lowest point

• rotate the revolving nosepiece so that the scanning objective is in the viewing position

• clean stage, objectives and oculars with lens paper and cleaning solution

• wind the cord around the base and use two hands (one on base and one on the arm) to place back into bench storage cabinet

how can you adjust the intensity of the light?

voltage regulator

what allows light to be passed through to the subject to be magnified?

iris diaphragm

how do you adjust the position of the condenser?

• condenser adjustment knob

  • alterating the position affects the contrast of what is being observed

base

provides stable platform to minimize the vibration transmitted to the scope

illuminator

light source of the microscope

condenser

system of lenses that focuses the light on the subject to be observed

mechanical stage

the site where the microscope slide is placed

what moves the slide?

stage adjustment knobs

how to move mechanical stage?

• two focus knobs on the left and right of microscope

• coarse focus adjustment: larger and can only be used with scanning and low power objectives

• fine focus adjustment: smaller and should be used with the high power or oil immersion objectives

coarse focus adjustment

larger and can only be used with scanning and low power objectives

fine focus adjustment

smaller and should only be used with the high power or oil immersion objectives

parfocal

switch from one objective to another with very little need to refocus

parcentral

you can switch from one objective to another with very little re-centering of your specimen

scanning objective

• 4X

• red ring

low power objective

• 10X

• yellow ring

high power objective

• 40X

• blue ring

oil immersion

• 100X

• white ring

why do you use oil for oil immersion?

to reduce the amount of image distortian caused by light refraction

coccus

diplococcus

streptococcus

staphylococcus

bacillus

streptobacillus

diplobacillus

palisades

coccobacillus

vibrio

spirillum

spirochete

pure culture

consists of cells of one species of bacteria

why is attaining pure culture important?

allows further experimentation to identify the bacteria and determine drug sensitivities

T streak method

gram positive bacteria

• thick, relatively rigid layer of peptidoglycan

• teichoic acid

• liptoteichoic acid

gram negative bacteria

• thinner less rigid layer of peptidoglycan

• phospholipid bilayer outside the peptidoglycan (outer membrane)

what does the outer membrane have?

lipopolysaccharides (LPS)

LPS

referred to as a endotoxin, it evokes a strong immune system reaction

what is mycobacterium tuberculosis responsible for?

tuberculosis

a positive staining result will be reported as what?

AFB⁺

reagents for Ziehl-Neelson protocol

carbolfuchsin → acid alcohol → loeffler’s methylene blue

gram staining reagents

crystal violet → gram’s iodine → ethyl alcohol → safranin