Brainscape's Knowledge GenomeTM

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


See full index

qs > Microbiology > Flashcards

Microbiology Flashcards

1
Q

How is gram staining done?

A

Come In And Stain
crystal violet
Iodine
Acetate/Alcohol
Safranin counterstain

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

What does gram positive bacteria look on gram stain?

A

Purple
retain crystal violet

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

What does gram negative bacteria look on gram stain?

A

Pink
decolorise + counterstain

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

What shape are gram positive bacteria usually?

A

mainly cocci

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

What shape are gram negative bacteria usually?

A

mostly bacilli

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

What is blood agar?

A

sheep + horse blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is chocolate agar?

A

BA cooked for 5 mins at 80C to release some nutrients (allows more organisms to grow eg fastidious organisms like H. influenza or Neisseria meningitidis)

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

What is CLED agar?

A

Cysteine Lactose Electrolyte deficient

mainly for urinary bacteria analysis (= good IDing Ecoli; can diff from salmonella + shigella w/ lactose fermentation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What color is E.coli and salmonella + shigella on CLED agar

A

E.coli = yellow

salmonella + shigella = Blue

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

What is MacConkey agar?

A

contains natural red dye + lactose
differentiates lactose fermenting gram -ve bacilli (E.coli = pink)

and no lactose fermenter (salmonella, shigella = yellow/colorless)

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

What is gonococcus agar?

A

for neisseria culture also shows w bad growth on BA and growth on chocolate agar

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

What is XLD agar?

A

differentiate salmonella + shigella

salmonella = red with black centers

shigella = red only

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

What is sabouraud agar?

A

fungal culture eg
- candida albicans (raised cream color colonies)

  • aspergillus (green/blue mold)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does gram positive catalase positive cluster indicate?

A

clusters = Steph
“bunch of grapes”

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

What does gram positive catalase negative chains indicate?

A

Chains = strep

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

What does gram positive catalase positive coagulase positive cluster indicate?

A

S. aureus

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

What does gram positive catalase positive coagulase negative cluster indicate?

A

other staph ( S. sapophyticus, S. epidermis)

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

What test comes after gram positive catalase negative?

A

haemolysis on BA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does gram positive catalase negative alpha haemolysis chains indicate?

A

partial haemolysis
appears green

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

What does gram positive catalase negative beta haemolysis chains indicate?

A

full haemolysis

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

What does gram positive catalase negative gamma haemolysis chains indicate?

A

enterococcus

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

What test follows alpha haemolysis?

A

Optochin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What test follows beta haemolysis?

A

lancefield grouping (group A, B, C, G antigenic group)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does gram positive catalase negative alpha haemolysis optochin resistant chains indicate?

A

S. viridans

25
Q

What does gram positive catalase negative alpha haemolysis optochin sensitive indicate?

A

S. pneumoniae

26
Q

What does gram positive catalase negative beta haemolysis Group A indicate specifically?

A

S. pyogenes

27
Q

What does gram positive catalase negative beta haemolysis Group B indicate specifically?

A

S. agalactiae

28
Q

What does gram positive catalase negative beta haemolysis Group B indicate generally?

A

neonatal sepsis + meningitis in neonates

29
Q

What does gram positive catalase negative beta haemolysis Group A, C, G indicate generally?

A

tonsilitis, pharynigitis, skin infection

30
Q

How is S. aureus differentiated from other staphs?

A
  1. coagulase test
  2. culture on blood agar
31
Q

How does staph show on coagulase test?

A

S. aureus will coagulate, other staphs will not

32
Q

How does staph show on blood agar?

A

S. aureus colonies are GOLD
aureus = GOLD while other staph are colorless

33
Q

How are gram negative bacteria cultures?

A

MacConkey/CLED/XLD

34
Q

What color are lactose fermenting bacteria on agar

A

pink

35
Q

What bacteria is suggested by pink lactose fermenting colonies?

A

colliforms

E. coli/ Klebsiella

36
Q

What test follows up yellow non lactose fermenting colonies?

A

Oxidase test (CLED PLATE)

37
Q

What does oxidase-positive non-lactose fermenting colonies suggest?

A

pseudomonas/aueruginosa

38
Q

What does oxidase-negatuive non-lactose fermenting colonies suggest?

A

colliforms (salmonella, shigella)

39
Q

What plate is used to determine salmonella or shigella colonies?

A

XLD plate

40
Q

What does red colonies with black centers on XLD plate suggest?

A

salmonella

shigella = red

41
Q

What does S. aureus have that other staphs do not have?

A

coagulase and DNAase

42
Q

What does S. aureus have that other staphs do not have?

A

coagulase and DNAase

43
Q

What are the sterile sites of the body?

A

Blood
CSF
pleural fluid
peritoneum
joints
urinary tract
lower resp tract

44
Q

What are the two main approaches for diagnosing viral infections?

A

viral detection = e microscopy, PCR

serology testing = ELISA, immunofluorescence, complement fixation test

45
Q

What is the preferred method of viral detection?

A

PCR = v fast + v sensitive, but the risk of a false positive

46
Q

What does serology testing do?

A

detected Igs against the virus

47
Q

What is important for running PCR?

A

need to suspect virus beforehand (so know what to expect)

quick
cheap
v sensitive

can test for multiple viruses simultaneously 9use mix of primers)

48
Q

What are the diagnostic swabs for infection?

A

Green = viral
Black (charcoal) = bacteral

49
Q

What does VZV cause and how does it present

A

Causes shingles + red painful rash conferred to single dermatome

50
Q

What does EBV cause?

A

infectious mononucleosis (glandular fever)

51
Q

What is a DDx for EBV?

A

S. pyogenes throat infection = both present with white yellowish purulent lining over the tonsils even through viral infections typically non purulent

52
Q

How is S. pyogenes DDx excluded form EBV?

A

black charcoal swab to exclude S. pyogenes

53
Q

How is EBV diagnosed?

A

EBV not diagnosed w green viral swab liek most viruses

54
Q

How does EBV appear on blood tetss

A

FBC -> atypical lymphocytes - basophilic cytoplasm + prominent nucleolus

Serology = EBV Ig w/ clotted sample
- do ELISA test;
- IgM positive = acute EBV
- IgG EBV positive = chronic/prior infection

55
Q

What are symptoms of EBV infectious mononucleosis

A

cough, fever, splenomegaly

56
Q

What antibody is produced against streptolysin toxin?

A

Anti streptolysin titre

57
Q

How long does blood film, PCR and ELISA take respectively?

A

blood film - in house
PCR = next day
ELISA = 1-2 days

58
Q

How is EBV treated?

A

supportive therapy (fluids, analgesia)
+ avoid contact sports for 6 weeks to prevent splenic rupture

59
Q

What test confirms S. pyogenes result?

A

latex agglutination test

qs (4 decks)

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