Gram Positive Pathogens Flashcards
(167 cards)
1
Q
T/F. Streptococcus pyogenes is catalase positive.
A
False. Catalase negative
2
Q
T/F. Streptococcus pyogenes is facultative anaerobe.
A
False. Microaerophilic
3
Q
T/F. Streptococcus pyogenes is beta hemolytic.
A
True.
4
Q
What are the adherence factors associated with S. pyogenes?
A
M proteins and lipoteichoic acid
5
Q
What are the virulence factors associated with S. pyogenes?
A
Streptokinase and hyaluronidase
6
Q
T/F. S. pyogenes produce endotoxin.
A
False. Exotoxin
7
Q
What are the exotoxin associated with S. pyogenes?
A
Erythrogenic toxin and pyrogenic toxin.
8
Q
Provide a representative organism of Group A Streptococcus.
A
S. pyogenes
9
Q
S. pyogenes produces this toxin which damages cell membrane of capillary epithelium giving rise to scarlet fever.
A
Erythrogenic toxin or pyrogenic toxin
10
Q
S. pyogenes produces this toxin which activates the host sepsis mediators (interleukin 1) leading to toxic shock syndrome.
A
Pyrogenic toxin or erythrogenic toxin
11
Q
Which microorganism produces erythrogenic or pyrogenic toxin which damages cell membrane of capillary epithelium giving rise to scarlet fever?
A
S. pyogenes
12
Q
What are the clinical findings associated with S. pyogenes?
A
Skin infections
Pharyngitis
Scarlet fever
Toxic shock syndrome
Necrotizing fasciitis
13
Q
What are the three presentations of skin infection by S. pyogenes?
A
Pyoderma
Impetigo
Erysipelas
14
Q
Treatment for S. pyogenes
A
high-dose penicillin with clindamycin and erythromycin
15
Q
Diagnostic procedure for S. pyogenes
A
Gram stain, culture, and throat swab
16
Q
B hemolysis by S. progenes is caused by what virulence factors?
A
Streptolysin O and S
17
Q
T/F. Lipoteichoic acid serves as virulence factor for S. pyogenes.
A
False. Adherence factor
18
Q
What properties does M protein provide for S. pyogenes?
A
adherence factor, anti-phagocytic, antigenic
19
Q
T/F. Streptococcus agalactiae is a catalase negative organism.
A
True.
20
Q
T/F. Streptococcus agalactiae is a aerophilic organism.
A
False. Facultative anaerobe
21
Q
T/F. Streptococcus agalactiae is capable of alpha hemolysis.
A
False. beta hemolysis
22
Q
Streptococcus agalactiae can be acquired by babies during deliver and cause what diseases?
A
Neonatal pneumonia
Neonatal meningitis
Neonatal sepsis
23
Q
Give a representative organism for Group B Streptococcus.
A
S. agalactiae
24
Q
What are the clinical findings associated with S. agalactiae?
A
Neonatal meningitis
Neonatal pneumonia
Neonatal sepsis
25
Treatment for S. agalactiae
Penicillin
26
Diagnostics of S. agalactiae
Gram stain of CSF or urine
Culture of CSF, urine, or blood
27
Provide the representative organisms of the Viridans Group.
Streptococcus mitis, S. mutans, S. salivarius, , S. intermedius and S. anginosus
28
T/F. Viridans infection usually start as dental infection but organism may travel the blood stream through cuts in the oral cavity and cause subacute endocarditis.
True.
29
T/F. The endocarditis produced by viridans is acute similar to the endocarditis produced by Staphylococcus aureus.
False. Subacute
30
Viridans group is catalase positive.
False. Catalase negative
31
T/F. Viridans are facultative anaerobe but may be microaerophilic.
True.
32
What are the clinical presentations associated with the viridans group?
Subacute endocarditis
Dental carries
Liver or brain abscesses
33
T/F. Viridans are beta hemolytic but may also be gamma hemolytic.
False. alpha hemolytic but may also be gamma hemolytic
34
This adherence factor allow viridans to adhere to heart valves.
extracellular dextran
35
What member of the viridans group produces dental caries?
S. mutans
36
What member of the viridans group produces brain or liver abcesses?
S. intermedius
37
Treatment for viridans group
penicillin
38
Diagnostic for viridans group
gram stain and culture
39
What are representatives of enterococcus Group D Streptococcus?
Enterococcus faecium and E. faecalis
40
What are representatives of non enterococcus Group D Streptococcus?
Streptococcus bovis, and S. equinis
41
T/F. Group D Streptococci are catalase positive organisms.
False. Catalase negative
42
T/F. Group D Streptococci are usually gamma hemolytic but maybe beta hemolytic.
False. Usually alpha but may be gamma
43
This adherence factors allows Group D Streptococcus to adhere to heart valves.
Extracellular dextran
44
What are the clinical findings associated with group D enterococcus?
Subacute endocarditis
Biliary tract infections
UTI
45
Treatment for group D Streptococcus
Ampicillin + aminoglycoside
46
Diagnostics for Group D Streptoccus
gram stain
Culture: enterococci at 40% bile and 6.5% NaCl; non enterococci in bile only
47
T/F. Culturing Group D non enterococci require bile and salt while culturing Group D enterococci require bile only.
False. non entero - bile only; entero - bile and salt
48
This organism is the primary cause of bacterial pneumonia and meningitis in adults, and otitis media in children.
Streptococcus pneumoniae
49
T/F. S. pneumoniae cells are arranged in chains.
False. Paired spheres (diplococci)
50
What are the virulence factors associated with S. pneumoniae?
capsules and pneumolysin
51
This virulence factor associated with S. pneumoniae binds to cholesterol in host-cell membranes.
Pneumolysin
52
Clinical findings associated wit S. pneumoniae
pneumonia
meningitis
sepsis
otitis media in children
53
Treatment for S. pneumoniae
Penicillin
Erythromycin
Ceftriaxone
Vaccine
54
Diagnostic for S. pnemoniae
gram stain, culture (does not grow in optochin and bile), positive Quellung reaction
55
How is S. pneumoniae differentiated from S. mitis?
susceptibility to optochin
56
T/F. Staphylococcus aureus is a catalase negative microorganism.
False. Calatase positive
57
T/F. S. aureus appear as chains of spheres.
False. grape-like clusters of spheres
58
T/F. S. aureus is alpha hemolytic.
False. S. aureus is beta hemolytic
59
T/F. All Staphylococcus species are coagulase positive.
False. Only S. aureus. S. epidermidis and S. saprophyticus are coagulase negative
60
This virulence factor of S. aureus binds IgG and prevents phagocytosis.
Protein A
61
This virulence factor of S. aureus induces clots as protection from phagocytes.
Coagulase
62
This virulence factor of S. aureus destroys RBC, neutrophiles, macrophages, and platelets.
Hemolysin
63
This virulence factor of S. aureus destroys WBC.
leukocidins
64
This virulence factor of S. aureus inactivates penicillin.
Penicillinase
65
This virulence factor of S. aureus breaks down hyaluronic acid.
Hyluronidase
66
This virulence factor of S. aureus lyses formed fibrin clots.
Staphylokinase
67
This virulence factor of S. aureus degrades fats and oils on skin
Lipase
68
This toxin produced S. aureus causes scalded skin syndrome.
Exfoliatin
69
What are the toxins produced by S. aureus
Enterotoxin
Toxic shock syndrome toxin (TSST-1)
Exfoliatin
70
What are clinical findings associated with the exotoxins produced by S. aureus.
Gastroenteritis
TSS
Scalded skin syndrome
71
What are clinical findings associated with direct invasion by S. aureus.
Pneumonia
Meningitis
Acute bacterial endocarditis
UTI
etc.
72
Treatment for S. aureus
Penicillinase- resistant penicillins
1st gen cephalosporins
Clindamycin
73
Diagnosis for S. aureus
Gram stain
Culture (B-hemolytic, golden yellow pigment)
catalase (+)
coagulase (+)
74
Culturing S. aureus in blood agar produces what characteristic morphology?
B hemolysis
Golden yellow pigment
75
What are characteristic culture morphology of Bacillus species.
Aerobic
Hemolysis in B. cereus
Gelatin liquefaction
Inverted tree morphology in galatin stabs
76
What are representative of aerobic, spore forming rods?
Bacillus anthracis
B. cereus
77
T/F. As opposed to Clostridium species, Bacillus species are anaerobic.
False. Bacillus species are aerobic.
78
T/F. Bacillus species as opposed to Clostridium always have a terminal spores.
False. Always have spores located centrally.
79
T/F. B. anthracis primarily affects herbivores.
True.
80
T/F. Humans are directly infected by B. anthracis.
False. humans are infected via contact with diseased animals
81
B. anthracis in humans are primarily through inhalation of spores.
False. 95 cutaneous, 5% inhalation, GI anthrax is rare
82
In animal hosts, B. anthracis portal of entry is through?
Mouth
83
The capsule of B. anthracis is encoded in what plasmid?
pXO2
84
The capsule of B. anthracis is composed of what chemical?
poly-D-glutamic acid
85
The capsule of B. anthracis confers what effector?
Prevention of phagocytosis
86
T/F. B. anthracis is a spore former.
True.
87
The exotoxins of B. anthracis is encoded in what plasmid?
pXO1
88
This exotoxin produced by B. anthracis, similar to B subunit of an AB toxin, promotes entry of the edema factor into host cells.
Protective antigen
89
This exotoxin produced by B. anthracis, similar to an A subunit of a AB toxin, performs the toxic function by impairing neutrophil thereby causing massive edema.
Edema factor
90
This exotoxin produced by B. anthracis stimulates release of tumor necrosis factor.
Lethal factor
91
This clinical finding associated with B. anthracis is characterized by painless, black vesicles.
Cutaneous anthrax
92
This clinical finding associated with B. anthracis is characterized by abdominal pain, vomiting, and bloody diarrhea.
GI anthrax
93
Clinical findings associated with B. anthracis
Cutaneous, pulmonary, and GI anthrax,
94
Treatment for B. anthracis
Ciprofloxacin
Doxycycline
Raxibacumab (pulmonary)
Vaccines
95
Diagnostic for B. anthracis
Gram stain
Culture
Serology
PCR of nasal swab
96
T/F. Bacillus cereus is motile and capsulated.
False. motile but non-encapsulated
97
This microorganism causes food poisoning when spores are ingested.
B. cereus
98
T/F. B. cereus produces endospores.
True.
99
What are the two types of enterotoxin produced by B. cereus.
heat-labile toxin
heat-stable toxin
100
This enterotoxin produced by B. cereus causes nausea, abdominal pain, and diarrhea.
heat-labile toxin
101
This enterotoxin produced by B. cereus causes nausea and vomiting but limited diarrhea.
heat-stable toxin
102
What are the clinical findings associated with B. cereus?
Food poisoning: nausea, vomiting, diarrhea
Bacteremia/endocarditis: rare
103
Treatment for B. cereus
Vancomycin
Clindamycin
No treatment for food poisoning
104
Diagnostic for B. cereus
Culture from contaminated food
105
What is diagnostic procedure for C. botulinum
Gram stain and culture
106
T/F. As opposed to Bacillus species, Clostridium have spores that is always centrally located.
False. Clostridium spores may be central, subterminal, or terminal
107
T/F. Clostridium species are peritrichously-flagellated.
True
108
T/F. Unlike Bacillus species, Clostridium species are generally anaerobes with few aerotolerant.
True.
109
T/F. Clostridium species are generally alpha hemolytic and grows well in blood-enriched media.
False. Beta hemolytic
110
Treatment for C. botulinum
Antitoxin for WB and FB
BIG IV for IB
Penicillin
Intubation and vent
Surgical debridement
111
This Clostridium species are mainly found in soil, canned or bagged food products, smoked fish, and honey.
C. botulinum
112
This microorganism causes flaccid paralysis.
C. botulinum
113
What are the three presentations of botulism?
infant, adult (food-borne), and wound botulism
114
In botulism, the toxin inhibits the release of what compound from peripheral nerves causing inability to contract muscles?
acetylcholine
115
T/F. Toxins of C. botulinum is released while the organism is still alive.
False. released upon death of bacterium
116
This presentation of botulism is characterized by GI symptoms, cranial nerve palsies, muscle weakness, and respiratory paralysis.
Food-borne botulism
117
This presentation of botulism is characterized by the same symptoms as food-borne botulism but without the GI symptoms.
wound botulism
118
T/F. C. tetani infection is usually caused by skin trauma by any spore- contaminated object.
True.
119
Sustained contraction of skeletal muscles is called?
tetany
120
This toxin produced by C. tetani causes sustained contraction of skeletal muscles.
Tetanospasmin
121
Tetanospasmin inhibits the action of what type of neurons?
Renshaw cell interneuron
122
Tetanospasmin inhibits the action of Renshaw cell interneuron preventing release of what inhibitory neurotransmitters, leading to high frequency impulses to the muscle?
GABA and glycine
123
Clinical findings for C. tetani
Muscle spasms
Lockjaw
Risus sardonicus
Respiratory muscle paralysis
124
This characteristic appearance of patients infected with C. tetani is produced by the locking of the jaws due to constant contraction of the jaw muscles.
risus sardonicus "grinning face"
125
Treatment for C. tetani
Tetanus toxoid (part of DTaP vaccine)
Antitoxin (human tetanus immune globulin)
Clean the wound
Metronidazole or penicillin
126
This Clostridium species causes gas gangrene, found in soil, and rampant as one of the primary causes of death in soldiers before penicillin.
C. perfringens
127
The alpha toxin of C. perfringens is what kind of enzyme?
lecithinase
128
This clinical finding associated with C. perfringens is characterized by exposed necrotic skin and crepitus which is the appearance of moist, spongy, crackling consistency in the wound due to pocket of gas.
Cellulitis/wound infection
129
Primary presentation of C. perfringens.
Cellulitis/wound infection
130
This characteristic appearance of C. perfringens wound infection produces moist, spongy, crackling consistency due to pockets of gas.
Crepitus
131
This presentation of C. perfringens infection causes destruction of muscles.
myonecrosis
132
This presentation of C. perfringens infection is caused by ingested contaminated food and characterized by watery diarrhea.
diarrheal illness
133
Treatment for C. perfringens infection
Surgery (may include amputation)
Penicillin
Hyperbaric oxygen
134
This microorganism causes antibiotic- associated pseudomembranous colitis.
C. difficile
135
This presentation of C. difficile infection is characterized by red, inflamed mucosa and areas of white exudate.
pseudomembranous colitis
136
This toxin produced by C. difficile causes diarrhea
Toxin A
137
This toxin produced by C. difficile is cytotoxic to the colonic cells.
Toxin B
138
This newly discovered toxin produced by C. difficil produces 15 to 20 times more toxins
Clostridium difficile binary toxin (CDT)
139
Treatment for C. difficile infection
Discontinue antibiotics
Fidaxomycin
Oral vancomycin
Metronidazole
Fecal transplantation
140
T/F. As opposed to Clostridium and Bacillus species, Corynebacterium diphtheriae are non spore forming.
True.
141
T/F. Corynebacterium diphtheriae are constantly rod shaped.
False. Coccobacillus/pleomorphic rods
142
T/F. C. diphtheriae is aerobic organism.
False. Facultative anaerobic
143
T/F. C. diphtheriae is catalase positive.
True
144
T/F. C. diphtheriae is motile.
False. nonmotile
145
As opposed to Listeria monocytogenes, C. diphtheriae is non-motile.
True. Motility test to differentiate Listeria monocytogenes from C. diphtheriae
146
The toxin produced by C. diphtheriae is what kind of toxin?
AB toxin
147
This toxin produced by C. diphtheriae blocks EF-2, inhibiting protein synthesis.
A subunit
148
This toxin produced by C. diphtheriae provides entry into cardiac and neural tissues.
B subunit
149
Clinical findings of C. diphtheriae.
diphtheria
150
This disease caused by C. diphtheriae is characterized by mild sore throat, fever and pseudomembrane on pharynx.
diphtheria
151
T/F. Similar to sore throat caused by S. pyogenes, C. diphtheriae causes the same symptoms but with darker coloration of exudates.
True.
152
Treatment for C. diphtheriae infection.
Antitoxin
Penicilline or erythromycin
Vaccine: DTAP
153
This microorganism appear as dark colonies in culture of potassium-tellurite
agar.
C. diphtheriae
154
This microorganism appear as reddish granules after staining with methylene on Loeffler's culture.
C. diphteriae
155
Culture medium for C. diphtheriae
potassium-tellurite agar - dark black colonies
Loeffler's medium - reddish granule after staining with methylene blue
156
This microorganism is found in wide range of environments, survives at low temp (4oC), low pH, high salt, and is associated with dairy products or pre-packed raw produce.
Listeria monocytogenes
157
T/F. L. monocytogenes appears as long rods.
False. Short rods.
158
T/F. L. monocytogenes is microaerophilic.
False. Facultative anearobic
159
T/F. L. monocytogenes is catalase-negative.
False. Catalase positive.
160
T/F. L. monocytogenes is alpha hemolysis.
False. beta hemolysis
161
Virulence factors associated with L. monocytogenes
Listeriolysin O and phospholipases
162
What effector do its virulence factors provide to L. monocytogenes.
evasion of phagocytosis
163
Other than Group B Strep, what other organism causes neonatal meningitis.
L. monocytogenes
164
What is the clinical presentation of L. monocytogenes in pregnant women?
septicemia
165
What is the clinical presentation of L. monocytogenes in immunosuppressed patient?
Meningitis
166
Treatment for L. monocytogenes
Ampicillin
Trimethoprim/ sulfamethoxazole
167
Diagnostic for L. monocytogenes
gram stain, culture
