STUDY GUIDE EXAM 1 Flashcards
(98 cards)
1
Q
Bacillus cereus
A
Gm +
2
Q
Bacillus subtilis
A
Gm +
3
Q
Clostridium spp.
A
Gm+
4
Q
Corynebacterium xerosis
A
Gm +
5
Q
Enterobacteria aerogenes
A
Gm -
6
Q
Enterococcus faecalis
A
Gm -
7
Q
Escherichia coli
A
Gm -
7
Q
Pseudomonas aeruginosa (BSL2)
A
Gm-
8
Q
Micrococcus luteus
A
Gm+
8
Q
Mycobacterium smegmatis
A
Gm +
9
Q
Salmonella typhymurium
A
Gm+
10
Q
Serratia marcescens
A
Gm-
11
Q
Staph aureus (BSL2)
A
Gm+
12
Q
Staph epidermidis
A
Gm+
13
Q
Strep mitis
A
Gm+
14
Q
Strep mutans
A
Gm+
15
Q
Strep salivarius
A
Gm+
16
Q
Strep sanguis
A
Gm+
17
Q
special methods used to minimize contamination when handling microorganisms
A
aseptic technique
18
Q
microorganisms are transferred from one medium to another for fresh growth
A
subculturing
19
Q
GRAM STAIN: what is the primary stain?
A
crystal violet
20
Q
GRAM STAIN: what is the mordant?
A
iodine
21
Q
GRAM STAIN: what is the destain?
A
alcohol wash
22
Q
GRAM STAIN: what is the counterstain?
A
safranin
23
GRAM STAIN: what species are used?
Staph aureus +
E. coli -
B. cereus +
24
ACID FAST STAIN: what is the primary stain?
carbol fuchsin + triton X detergent
25
ACID FAST STAIN: what is the destain?
acid alcohol
26
ACID FAST STAIN: what is the counterstain?
methylene blue
27
ACID FAST STAIN: species
M. smegmatis
staph aureus
28
ACID FAST STAIN: what color do acid-fast organisms stain?
red/pink
29
ACID FAST STAIN: what color do non-acid fast organisms stain?
blue
30
SPORE STAIN: primary stain
malachite green
31
SPORE STAIN: destain
heat/water
32
SPORE STAIN: counterstain
safranin
33
SPORE STAIN: species
clostridium & bacillus
34
SPORE STAIN: what color do the spores remain with heat?
malachite green
35
CAPSULE STAIN: primary
crystal violet
36
CAPSULE STAIN: counterstain
copper sulfate
37
CAPSULE STAIN: species
Klebsiella pneuonia
38
The properties of the bacterial cell wall determine how the bacterial cell will retain different _____
stains
39
inhibits the growth of one type of bacteria while allowing the growth of another.
facilitates bacterial isolation
selective media
40
examples of selective media
phenylethyl alcohol agar
41
distinguishes among morphologically & biochemically related organisms
may change bacteria phenotype, or the appearance of the media may change as a result of bacterial metabolism
differential media
42
PEA: what makes it selective?
gram + species grow well
43
PEA: selective for
S aureus (gm + organisms)
44
PEA: inhibits
E. coli (gm -)
45
PEA: what species grows?
S. aureus
46
PEA: what species is inhibited?
E. coli
47
PEA: genus & species
E. coli, E. faecalis, S. aureus
48
MANNITOL SALT: what makes it selective?
Salt concentration
49
MANNITOL SALT: selective for
halophiles & staph
50
MANNITOL SALT: inhibits
bacterial growth (besides staph)
51
MANNITOL SALT: carbohydrate
mannitol
52
MANNITOL SALT: indicator
phenol red
53
MANNITOL SALT: appearance for pH
pH below 6.8 = yellow (fermenters)
pH at 6.8 - 8.2 = red (non-fermenters)
pH 8.2 and above = fuschia
54
MacConkey: what makes it selective?
contains crystal violet- inhibits cell redox
55
MacConkey: selective for
gm - bacteria
56
MacConkey: inhibits
growth of gm +
57
MacConkey: carbohydrate
lactose
58
MacConkey: indicator
neutral red
59
MacConkey: appearance
fermenters = pink (bile salts ppt out, neutral red absorbed onto colony: E. coli)
non-fermenters = tan (salmonella typhi)
60
EMB: what makes it selective?
lactose fermentation
61
EMB: selective for
gm - bacteria
62
EMB: inhibits
growth of gm + bacteria
63
EMB: carbohydrate
lactose
64
EMB: indicator
methylene blue
65
EMB: appearance
E. coli is metallic green: high lactic acid dyes into surface of colony
lactose fermenter are thick & pink (enterobacter aerogens)
non-lactose fermenters are colorless (S. typhi)
66
complete lysis, media is color depleted
beta
66
example of beta
Strep lancefield
Staph aureus
67
incomplete lysis, results in greenish halo around bacteria
alpha
68
example of alpha
Strep mitis
Strep pneumonia
69
no lysis, no change in media
gamma
70
example of gamma
Strep salivarius
E. faecalis
71
Known ingredients in carefully measured concentrations, typically a single sugar as the carbon and
energy source, maybe an inorganic nitrogen source, various mineral salts and/or growth factors.
The exact chemical composition of the medium is known. Example: Glucose salt broth
defined
72
Protein: partially digested organic material from soy, yeast, or animal proteins (peptone and
tryptone) from milk or meat. Glucose or other sugars are the main carbon and energy source. The
combination of peptides + sugar creates a medium rich in organic nutrients and minerals. The exact
chemical composition is unknown. Example: TS (Tryptic Soy), Beef heart infusion broth
complex
73
Can be complex or chemically defined but is supplemented with growth-promoting or growth-
inhibiting additives to encourage or suppress growth. The additives may be species- or organism-
selective. Example: PEA agar, Crystal Violet Agar
selective
74
Contains a dye or indicator that can be used to distinguish one organism from another on the same
plate. Examples: Mannitol Salt, MacConkey, EMB (all are Selective and Differential)
differential
75
Contains added components (like RBCs or Fetal Calf Serum) to encourage the growth of fastidious
organisms needing a rich nutritional environment. Example: Blood Agar (Enriched and Differential)
enriched
76
species that is an example of gamma hemolysis
enterobacter aerogenes (klebsiella aerogenes)
77
species that is an example of beta hemolysis
enterococcus faecalis (BSL2)
78
species that is an example of alpha hemolysis
alcaligenes faecalis
79
what species forms beta hemolysis around the colonies of streptococci grown under routine aerobic positions
streptolysin S
80
what species is oxygen-labile (O2 kills it)
streptolysin O
81
what species is oxygen stable?
streptolysin S
82
(Gm+ cocci) excretes an enzyme called
dextransucrase (glycosyl transferase), which
polymerizes sucrose into a large polymer, dextran
(dental plaque), plus fructose.
S. mutans
83
clings to the teeth and forms dental plaque,
in which bacteria reside and ferment fructose with
the formation of lactic acid = Dental caries
dextran
84
(Gm+ rod) produces lactic acid and
other organic acids that reduce the oral acid
concentration to a pH of less than 5. At this pH,
decalcification occurs and dental decay begins
L. acidophilus
85
SNYDER AGAR: is it selective, differential, enriched?
differential
86
SNYDER AGAR: what is it selective for?
lactobacillus in saliva
87
SNYDER AGAR: inhibits
growth of other bacteria
88
SNYDER AGAR: species
S. mutans
L. acidophilus
89
what does MSAT metabolize?
sucrose & glucose
90
MSAT: produces gummy mucoid colonies
strep salivarius
91
produces undulate colonies, with a granular
“Frosted-glass/Blue crystal”
appearance due to dextran synthesis
Strep mutans
92
MSAT: metabolize glucose only
strep mitis
enterococcus
93
are small, flat,
light blue.
strep mitis
94
are small,
and reduce tellurite to
produce dark, blue-black
colonies
enterococcus
95
Streptococcus mutans results in glucose and fructose. The glucose is then converted into dextran by Streptococcus mutans, while the fructose is converted into lactic acid by Lactobacilli. The Oxidase test is used to detect the presence of cytochrome c oxidase.
degradation of sucrose
