Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > Final Lab Practical > Flashcards

Final Lab Practical Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
0
Q

why is coccidioides immitis considered to be a dimorphic fungus?

A

It can grow as yeast or as mold depending on conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

what is the difference between mold and yeast (macro and micro)?

A

yeast are creamy looking, moist, large and oval

mold are not creamy or moist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the growth differences between fungus and bacteria?

A

fungi-grow slower, at a lower temperature, and lower pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the difference between vegetative hyphae and aerial hyphae?

A

Vegetative- grow down or into agar

aerial- grow above agar surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the difference between sporangiospores and conidiospores?

A

spor- spores grow inside of a sack

conid- spores at the end of hyphae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how are molds identified in the laboratory?

A

macroscopic and microscopic appearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define bacteriophage
lytic
plaque

A
  • virus that infects only bacteria
  • lyses or bursting of the host cell
  • area of clearing representing a virus blowing up a bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the purpose of making dilutions of the T-4 virus?

A

you need a countable plate of plaques

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define obligate intracellular parasite

lytic cycle

A
  • organisms that can only grow inside another living host cell
  • cycle in which virus infects and then bursts their host once the appropriate number of viruses have been synthesized, killing the host cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does a medium used for bacterial growth differ from media used for bacteriophage growth?

A

the virus uses the bacteria on the media to grow/infect. ordinary agar/broth but bacteria is used as host cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Differentiate between staphyloccocus and streptococcus by the catalase test

A

staph-positive, bubbles

strep-negative, no bubbles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the principle in the catalase and coagulase tests, what is the media used for each?

A

cat- does bacteria produce catalase enzyme, H2O2 (bubbles)

coag-does bacteria produce coagulase enzyme, rabbit plasma (white clumps)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

calculate the titer of phage in the original sample given teh numbe of plaques and dilution of the plate.
what is the unit??

A

plaque count X dilution factor X sample amount = PFU’s/ml of sample
PFU’s/ml

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

differentiate between the two species of Staphylococcus by the coagulase test and reaction on mannitol salt agar
BE ABLE TO SPELL!!

A

Staphylococcus aureus- coagulase (+), yellow salt agar (+)

Staphylococcus epidermidis- coagulase (-), no change in media (-)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is mannitol salt agar both a selective and differential media?

A

selective because of high salt and differential because of mannitol fermentation (if positive, bacteria will produce acid, which will change the pH of media, and change the color of media)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Determine species of Micrococcus by pigmentation or nitrate test result. BE ABLE TO SPELL

A

Micrococcus roseus- pink hue, (+) nitrate test (red at first, or no red after zinc)
Micrococcus luteus- yellow hue, (-) nitrate test(no color at first, red after zinc)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the gram result, morphology, and arrangement of staphylococcus and micrococcus?

A

gram (+), cocci, in clusters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where are staphylococcus and micrococcus found in the body?

A

skin and mucous membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

define carrier
MRSA
nosocomial

A
  • a person who harbors a pathogen but exhibits no symptoms
  • methylin resistant staphylococcus aureus
  • health-care acquired disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

name two substances that staphylococcus aureus produces to cause disease.

A
  1. coagulase enzyme

2. catalase enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

when do staphylococcus epidermidis and micrococcus cause disease?

A

they opportunistic pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

describe the difference between the types of hemolysis.

A

alpha-bruised
beta-lysed, clearing
gamma-no change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

why do you use the streak-stab method for blood agar inoculations?

A

let’s you see hemolysis better

23
Q

State the atmosphere used to grow streptococcus.

A

candle-jar, they are microaerophiles

24
Q

Differentiate the colony appearance of staphylococcus and streptococcus

A

staph-pigmented, convex, opaque, larger

strep-translucent, semi-opaque

25
Q

which enzyme helps differentiate all staphylococci from streptococci

A

catalase

26
Q

How did Lancefield divide the beta-hemolytic streptococci into groups?

A

c polysaccharide extracted from cell walls.

27
Q

what is the species name of Lancefield group A streptococci?

group B?

A
  • pyogenes

- agalactiae

28
Q

Which test is used on alpha streptococcus, what are the results?
beta streptococcus?

A

alpha-optochin sensitivity-streptococcus mitis is resistant, streptococcus pneumoniae is sensitive
beta-bacitracin sensitivity- group C streptococcus is resistant, streptococcus pyogenes is sensitive

29
Q

how is enterococcus different from other alpha hemolytic streptococcus?

A

enterococcus faecalis is the only one that is bile esculin positive, it is resistant to all sensitivity tests.

30
Q

where is enterococcus normally found in the body?

A

gastrointestinal tract

31
Q

Explain VRE

viridans streptococci

A
  • vancomysin resistant enterococcus

- other alpha hemolytic streptococci other than streptococcus pneumoniae

32
Q

name the organism that causes the following diseases:

  • community-acquired pneumoniae
  • dental cavities
  • neonatal septicemia
  • strep throat
  • urinary tract infection
A
  • streptococcus pneumoniae
  • viridans streptococci
  • Group B strep
  • Group A strep
  • Enterococcus
33
Q

what are the two major groups of gram (-) rods and what are the common characteristics of each group?

A

enterobacteriaceae-gram (-), ferment glucose, oxidase (-)

non “”- gram (-) bacilli, no ferment glucose, oxidase (+)

34
Q

which carbohydrate is used to determine whether a gram negative rod is a “nonfermenter’ or “enterobaceriaceae”?

A

glucose

35
Q

what carbohydrates are in the Kliger Iron Agar media?

A

KI agar contains glucose and lactose

36
Q

what carohydrate is in MacConkey agar?

A

lactose

37
Q

Why is MacConkey agar considered to be selective and differential media?

A

selects using bile salts and crystal violet, inhibits gram (+) growth, differential with lactose fermentation.

38
Q

what is an “enteric” organism?

A

normally part of normal flora of intestinal tract

39
Q

How are culture media designed to detect if a bacteria can produce a specific enzyme?

A

substrates for the enzyme are incorporated into culture medium along with an indicator system to detect products.

40
Q

what is the purpose of the Durham tube in the carbohydrate fermentation tubes?

A

detect gas formation

41
Q

name the specific tests that are part of the IMViC test?

A

indole, methyl red, voges-proskauer, citrate

42
Q

name three Enterobacteriaceae notmally found in the gi tract

A

escherichia coli
enterobacter arogenes
proteus vulgaris

43
Q

Name two Enterobacteriaceae that are major pathogens and state the disease that each causes.

A

Salmonella-gastroenteritis and typhoid fever

Shigella-bacterial dysentery

44
Q

Name one of many commercial test systems used to identify Gram (-) rods in clinical labs.

A

Enterotube, AP120E, Micro ID

45
Q

Explain how CNA and MacConkey agar aid in the identification of bacteria in a mixed unknown.

A

CNA-selective for gram (+) and differential for hemolysis

MacConkey- selective for gram (-), differential for lactose fermentation

46
Q

what does bacteria that grow on MacConkey and can fermet lactose look like?

A

Hot pink colonies

47
Q

what type of organism grows on macConkey agar?

A

Gram (-)

48
Q

what ingredient in the MacConkey agar will differentiate the organisms growing on the agar?

A

lactose

49
Q

what type of organism grows on CNA?

A

gram (+)

50
Q

How does the CNA medium inhibit the growth of gram negative rods?

A

It has narrow spectrum antibiotics in it to inhibit gram negative growth

51
Q

What ingredient in the CNA media allows differentiation of the organisms growing on the agar?

A

blood

52
Q

why is the CNA media incubated in the a candle jar?

A

microaerophilic

53
Q

why is a cotton swab used to obtain the sample from the original broth?

A

its a mixed culture and so it ensure we get both bacteria

54
Q

why is T. soy agar used to grow the “stock cultures”?

A

neutral media that sustains growth of all bacteria

55
Q

Why do you need to develop TWO flow charts in order to identify your unknown organisms?

A

we have two unknowns, we need a key for both of them.

Microbiology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions