2.1 Gram Positive, Catalase positive Bac Flashcards
1
Q
What is the composition of peptidoglycan?
A
N-acetylglucosamine
N-acetylmuramic acid
2
Q
Is peptidoglycan a singled or multilayered?
A
Multilayered
3
Q
The 2 composition of peptidoglycan is connected by?
A
Peptide bonds
4
Q
Gram positive cocci has a thick or thin layer of peptidoglycan?
A
Thick
5
Q
Gram-positive infections are?
A
Pyogenic
6
Q
How to differentiate gram positive Cocci?
A
Catalase test
7
Q
What can be found in catalase positive for Gram positive cocci?
A
Micrococcaceae
Staphylococcaceae
8
Q
What can be found in catalase Negative for Gram positive cocci?
A
Streptococcaceae
9
Q
What is the characteristics of Staphylococci?
A
Catalase positive
Clusters
Nonmotile
Non-spore forming
Aerobic or Facultative anaerobes
10
Q
What is the Gaseous composition for S. saprophyticus
A
Obligate Anaerobe
11
Q
Is staphylococcus non capsulated?
A
Yes
12
Q
Is staphylococcus Oxidase positive?
A
False
13
Q
What environment does staphylococcus grow on?
A
7.5% NaCl (Salt tolerance test)
14
Q
What reagent is used in catalase test?
A
3, 10, 30% hydrogen peroxide (H2O2)
15
Q
What is the molarity of H2O2 in staphylococcus?
A
3%
16
Q
How do we know if we isolated staphylococcus and micrococcaceae
A
Bubble formation
17
Q
What organisms can be seen in negative catalase test?
A
Streptococcus
18
Q
What are the clinically significant Normal flora species in Staphylococcaceae?
A
Aureus
Epidermidis
Saprophyticus
19
Q
Staphylococcus aureus is a normal flora of what part of the body?
A
Nares
20
Q
Staphylococcus epidemidis
A
Skin
21
Q
Staphylococcus saprophyticus is a normal flora of what part of the body?
A
Genital tract
22
Q
Most clinically significant species of Staphylococci
A
S. aureus
23
Q
Staphylococcus is usually present in skin surfaces, is it normal?
A
no
24
Q
S. aureus usually cause nosocomial infection?
A
True
25
What are the virulence factor for S. aureus?
Enterotoxins (A-E & G-J)
Exfoliative Toxin
Cytolytic toxins
Protein A
Beta Lactamase
26
Is S. aureus an opportunistic pathogens
True
27
A virulence factor of S. aureus that can survive 100 degrees Celsius for 30 mins which is a heat stable
Enterotoxins
28
What Enterotoxins of S. aureus are associated with Food poisoning?
A, B, D
29
Enterotoxin B of S. aureus is associated with what disease?
Pseudomembranous enterocolitis (colitis) / Ulcerative colitis
30
What does pseudomembranous colitis do in the lining of the intestine?
It produces pus which thickens the lining of the intestines.
31
A superantigen syndrome that stimulates T-cell proliferation which produce large amount of cytokines.
Toxic shock syndrome toxin-1
32
What enterotoxin is associated with TSST-1?
Enterotoxin F
33
TSST-1 can cause mensturating-associated TSS which is usually acquired by?
Unreplaced tampons
34
This virulence factor causes the skin to slough off which causes the SSS
Exfoliative toxin
35
Another name for exfoliative toxin
Epidermolytic toxin a and b
36
What disease or syndrome cause by exfoliative toxin
Scalded skin syndrome (Ritter disease)
Bullous impetigo (Blister-like)
37
A Cytolytic Toxin that can damage platelets, macrophages and can cause severe tissue damage.
Alpha hemolysin
38
A Cytolytic Toxin that acts on sphingomyelin in the plasma membrane of erythrocytes which is called "hot and cold" lysin
Beta hemolysin
39
What disease can be associated with gamma hemolysin?
Panton-Valentine Leukocidin
40
What is Panton-Valentine Leukocidin?
Elimination of neutrophils and Macrophages
41
Other name of coagulase in Staphylococci
Staphylocoagulase
Fibrinogen to fibrin
42
Other name of fibrinolysin in staphylococci?
Staphylokinase
Breaks fibrin
43
Protease
Cleaves protein
44
A spreading factor of staphylococcus
Targets patient connective tissue
hyaluronidase
45
Hydrolyzes lipids
lipase
46
IT is considered virulence marker of staphylococcus which can differentiate from other Staphylococcus spp.
Staphylocoagulase
47
Virulence factor of Staphylococcus is the ability to bind the Fc to IgG which blocks Phagocytosis
Protein A
48
Virulence factor that is responsible for drug resistance factor for Staphylococcus
Beta Lactamase
49
Patient has High fever and low bp level. In addition, the patient has high DIC. Patient said that he frequently uses tampons. What is the disease or syndrome associated with?
Toxic Shock syndrome Toxin-1
50
Earliest signs of TSST-1?
Exfoliative toxins
Ritter disease and Bullous Impetigo
51
What happens if TSST-1 is left untreated?
Multiple organ failure
52
What will happen if S.aureus penetrate to blood stream?
Endocarditis
Osteomyelitis
Arthritis
Nosocomial infection
53
What is the virulence factor for S. epidermidis
Exopolysaccharide slide or biofilm
- adheres to medical devices and provides refractoriness to host defense
54
What are the disease associated with S. epidermidis
Hospital acquired UTI
Prosthetic valve endocarditis (not wearing gloves)
55
How is hospital acquired UTI occur?
Unreplaced catheter
56
What is the virulence factor for S. saprophyticus
Adhere to epithelial cell lining in urogenital tract
57
What are the disease associated with S. saprophyticus
UTI
Common in young females
Sexual activity
58
A bacteria that can cause both community associated and hospital acquired infection.
It more virulent in prosthetic valve endocarditis than epidermidis
S. lugdunensis
59
What is the virulence facto of S. Lugdunensis?
Gene mecA
60
What is gene mecA?
Oxacillin resistant
61
It has a Vancomycin resistant as a virulence factor
S. Haemolyticus
62
What are the specimen for Staphylococcaceae
Aspirate
Swabs
63
Culture media for staphylococcus?
Blood agar
Colistin-Nalidixic acid
Phenylethyl alcohol agar
Mannitol salt agar
CHROM agar
64
What is the purpose of Blood agar in Staphylococcus
Enriched isolation
65
What is the purpose of Colistin-Nalidixic in Staphylococcus
Selective medium for gram positive cocci
66
What is the purpose of Mannitol salt agar in Staphylococcus
Selective and differential
67
What is the purpose of CHROM in Staphylococcus
Selective and Differential for Methicillin-resistant S. aureus
68
It test the ability to breakdown Hydrogen peroxide into oxygen and water
Catalase test
69
Amount of hydrogen peroxide use for Staphylococcaceae
3%
70
where 30% H2O2 is use for in catalase test
Mycobacterium and Neisseria
71
What organisms is positive for catalase in gram positive cocci?
Staphylococcus and micrococcus
72
What organisms is negative for catalase test in gram positive cocci?
Streptococcus
73
What is the indicator for catalase test if it is positive?
Bubbles
74
A test for the ability of the bacteria to convert fibrinogen to fibrin
This test can differentiate from aureus to other Staphylococci
Coagulase test
75
What are the 2 types of coagulase test?
Bound and free
76
What is the best sample for Staphylococcaceae
Aspirate
77
A type of coagulase test that uses slide method wherein plasma is put on the slide.
Bound coagulase
78
A type of coagulase test that uses a tube method
Free coagulase
79
How many hours to confirm if the free coagulase test is positive?
4-6 hrs
18-24 hrs if the there is no agglutination or clot on the first 4-6 hrs
80
What is the positive indicator for coagulase test?
Clot or clumping
81
What organisms is positive in coagulase test? why?
Staphylococcus aureus
Because of the presence of Staphylocoagulase
82
This test differentiate S. epidermidis and S. saprophyticus
Novobiocin test
83
It is a clear zone that surrounds the antibiotic which shows it's effectiveness and the susceptibility of the bacteria to it.
Zone of inhibition (16mm) - novobiocin
84
How many grams of Novobiocin is used in Novobiocin test?
5ug
85
What organisms is resistant to Novobiocin?
Staphylococcus saprophyticus
86
What organisms is susceptible to Novobiocin?
Staphylococcus epidermidis
87
What is being test for in Microdase test?
Cytochrome C
88
What differentiates in microdase test?
Staphyloccoci and Micrococcus
89
What is positive indicator for microdase test?
Blue to purple-blue
90
What organisms is positive in microdase test?
Micrococcus spp.
91
A selective and differential agar that uses NaCl
Ability to ferment mannitol
Mannitol salt agar
92
How many percentage of NaCl in Mannitol salt agar?
7.5%
93
What is the positive indicator for mannitol salt agar?
Fermentation (Yellow halo around growth)
94
What organisms is positive in mannitol salt agar?
Staphylococcus aureus
95
Other name for Bacitracin?
Bacitracin taxo A
96
What is the purpose of Bacitracin?
Differentiates micrococcus spp. to Staphylococcus spp.
97
What is the zone of inhibition for bacitracin
10mm
98
What is the positive organisms for bacitracin?
Micrococcus spp.
99
It test the ability to hydrolyze DNA
DNAse test
100
What are the 2 methods for DNase test?
Toluidine blue w/ Methyl green
HCl precipitation
101
What is the postive indicator for DNAse test?
Clear zone
102
What organisms is positive for DNAse test
Staphylococcus aureus
103
What is the principle for DNAse test?
Clearing
Break down DNA making a clearing zone
104
Test for the ability of the organism to hydrolyze the substrate L-pyrrolidonylβ-napththylamide to l-pyrrolidone and β-naphthylamine,
Pyrrolidonyl aminopeptidase
105
What is the positive indicator for pyrrolidonyl aminopeptidase?
Bright red after 5mins
106
What organisms is positive for pyrrolidonyl aminopeptidase?
Staphylococcus epidermidis and saprophyticus
107
What organisms is negative for pyrrolidonyl aminopeptidase?
Staphylococcus lugdunensis and haemolyticus
108
It is considered Gold standard for bacteria identification
Real time Polymerase chain Reaction
109
Next Gold standard considered after RTPCR in identifying bacteria?
Culture
110
This targets the rRNA sequences for Staphylococcal identification from from blood cultures
Qualitative nucleic acid hybridization assays
111
This detects turbidity of the bacteria and Continues to be integrated as U.S. Food and Drug Administration (FDA)
approval occur
Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry
112
Who issued the standard guidelines for antimicrobial susceptibility test
Clinical and Laboratory standards Institute (CLSI)
113
This encodes penicillin-binding proteins (Oxacillin resistant)
mecA gene
114
What antimicrobial is use to treat methicillin-resistant Staphylococcus aureus?
Vancomycin and Oxacillin
115
What is being use to determine methicillin resistance?
Cefoxitin
116
How cefoxitin confirms MRSA?
NO zone of inhibition (Resistant to Cefoxitin)
117
What is the drug of choice for MRSA?
Vancomycin
118
This antimicrobial is frequently use for Staphylococcal skin infections
Can also be use to treat MRSA
Clindamycin
119
What antimicrobial is use in D-zone test?
Erythromycin and Clindamycin disks
120
What is the presence of D-shaped for clindamycin say?
Induced clindamycin resistant
Meaning, Clindamycin cannot be use for treatment for staphylococcus infection.
121
Pseudomembranous ulcerative colitis is associated by what bacteria?
Staphylococcus aureus
Clostridium Difficile
