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M2.1 Flashcards

1
Q

gram positive cocci in clusters
catalase positive, coagulase positive

A

Staphylococcus aureus

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2
Q

STAPHYLOCOCCUS AUREUS
gram-positive cocci character?
colonies on blood agar?
catalase?
coagulase?
DNAse?
on mannitol salt agar?
“Gold” color is due the pigment?

A

gram-positive cocci in grape-like clusters
• b-hemolytic yellow or golden colonies on blood agar
• catalase-positive
• coagulase-positive
• DNAse- positive
• salt-tolerant on mannitol salt agar (halotolerant)
• “Gold” color is due the pigment staphyloxanthin

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3
Q

STAPHYLOCOCCUS AUREUS
HABITAT

A

human nose (anterior nares) and skin

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4
Q

STAPHYLOCOCCUS AUREUS
VIRULENCE FACTORS:
IMMUNOMODULATORS

A

Protein A
Coagulase
Hemolysins (cytotoxins)
PV Leukocidin
Catalase
Penicillinase

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5
Q

STAPHYLOCOCCUS AUREUS

prevents complement activation?
builds an insoluble fibrin capsule?
toxic to hematopoietic cells?
specific for white blood cells?
detoxifies hydrogen peroxide?
inactivates penicillin derivatives?

A

Protein A
Coagulase
Hemolysins (cytotoxins)
PV Leukocidin
Catalase
Penicillinase

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6
Q

STAPHYLOCOCCUS AUREUS
VIRULENCE FACTORS:
TISSUE PENETRANCE

A

Hyaluronidase
Fibrinolysin
(staphylokinase)
Lipase

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7
Q

STAPHYLOCOCCUS AUREUS
hydrolyzes hyaluronic acid? Spreading factor?

dissolves fibrin clots?

spread in fat-containing areas of the body?

A

Hyaluronidase
Fibrinolysin
(staphylokinase)
Lipase

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8
Q

STAPHYLOCOCCUS AUREUS
VIRULENCE FACTORS:
TOXINS (4)

A

Exfoliatin A and B
Enterotoxins (heat-stable)
Toxic shock syndrome toxin (TSST-1)
Alpha toxin

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9
Q

STAPHYLOCOCCUS AUREUS

superantigen causing epidermal separation?

superantigens causing food poisoning?

superantigen leading to toxic shock syndrome?
contaminated tampons?

causes marked necrosis of the skin and hemolysis?

A

Exfoliatin A and B
Enterotoxins
(heat-stable)
Toxic shock syndrome
toxin (TSST-1)
Alpha toxin

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10
Q

virulence factor that helps S. aureus evade the immune system early in infection

A

coagulase

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11
Q

factor involved in spreading the infection or breaking down clots later in the infection

A

fibrinolysin (staphylokinase)

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12
Q

Exofoliatin Toxin
causes epidermal separation on what layer?
what disease?
cleaves?

A

stratum granulosum

Scalded Skin Syndrome (aka Ritter Disease)

Desmoglein

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13
Q

Enterotoxin
Common food sources:
incubation period:

A

Heat stable

poultry, ham, meat, potato salad

Short, 1-8/ 1-6 hrs

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14
Q

A 19/F was rushed to the ER, febrile, hypotensive with
scarlatiniform rash, with areas of desquamation in her arms which were insignificant. She has had abdominal pain and loose bowel movement since yesterday. She is on her D4 of menses and uses tampons for the first time. She improved and was discharged. What is the most likely diagnosis

a. Scarlet fever
b. Scalded Skin Syndrome
c. Toxic Shock Syndrome
d. Food poisoning
In the previous case, wh

A

c. Toxic Shock Syndrome

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15
Q

In the previous case, what pathophysiologic mechanism is most
important in the progression of the clinical manifestation?
a. Exfoliatin toxin cleaves desmoglein
b. Presence of TSST-1, a superantigen, in the systemic
circulation
c. Consumption coagulopathy
d. Ingestion of heat-stable toxin

A

b. Presence of TSST-1, a superantigen, in the systemic
circulation

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16
Q

In the previous case, which of the following is correct regarding the
causative agent?
a. Catalase (-) Coagulase (+)
b. Gram positive cocci in tetrads
c. Possesses penicillinase enzyme
d. Optochin and Bacitracin Sensitive

A

c. Possesses penicillinase enzyme

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17
Q

STAPHYLOCOCCUS AUREUS
SPECTRUM OF DISEASE: PYOGENIC

A

Skin & Soft Tissue Infections
Acute Endocarditis
Osteomyelitis & Septic Arthritis

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18
Q

STAPHYLOCOCCUS AUREUS
DISEASE: PYOGENIC
• Skin & Soft Tissue Infections

A
  1. bullous impetigo
  2. folliculitis
  3. furuncles
  4. carbuncles
  5. cellulitis
  6. hidradenitis suppurativa
  7. mastitis
  8. surgical site infections
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19
Q

8/M from Bulacan presents with fever, cough and respiratory
distress. In the ER the patient was unstable and in tripod position.
CXR showed hazy infiltrates in bilateral lower lung fields with area
of cystic lucency in the middle lobe. AFB sputum smear (-), What is
the most likely causative agent?
a. Streptococcus pneumoniae
b. Klebsiella pneumoniae
c. Legionella pneumophila
d. Staphylococcus aureus

A

d. Staphylococcus aureus

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20
Q

Most common cause of acute endocarditis
o native valve (tricuspid valve) in IV drug users

A

Staphylococcus aureus

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21
Q

Most common cause of acute endocarditis
o native valve (tricuspid valve) in IV drug users

A

Staphylococcus aureus

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22
Q

INFECTIVE ENDOCARDITIS IN IV Drug user:

A

Staphylococcus aureus

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23
Q

INFECTIVE ENDOCARDITIS IN
Prosthetic valve:

A

Staphylococcus epidermidis

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24
Q

INFECTIVE ENDOCARDITIS IN s/p GU or GI procedures:

A

Enterococcus Faecalis

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25
Q

INFECTIVE ENDOCARDITIS IN(+) GI Malignancy:

A

Streptococcus bovis

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26
Q

INFECTIVE ENDOCARDITIS IN(+) GI Malignancy:

A

Streptococcus bovis

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27
Q

INFECTIVE ENDOCARDITIS IN Dental procedures:

A

Viridans streptococcus

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28
Q

INFECTIVE ENDOCARDITIS
most frequent valve involved in IV drug user

A

Tricuspid Valve

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29
Q

INFECTIVE ENDOCARDITIS most frequent valve involved EXCEPT in IV drug user

A

Mitral Valve

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30
Q

STAPHYLOCOCCUS AUREUS
DISEASE: PYOGENIC

Pneumonia

A
  1. nosocomial pneumonia
  2. VAP
  3. necrotizing pneumonia
  4. post-viral pneumonia

complicated by empyema, abscess or pneumatocele

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31
Q

STAPHYLOCOCCUS AUREUS
Osteomyelitis & Septic Arthritis

Spread?

involves in children?
more common in adults?

Abscess?
sequestered focus of osteomyelitis arising in the?

A

hematogenous spread or direct inoculation

long bones

vertebral osteomyelitis

Brodie abscess
metaphyseal area of a long bone

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32
Q

STAPHYLOCOCCUS AUREUS
SPECTRUM OF DISEASE: TOXIGENIC

A

Gastroenteritis
Scalded Skin Syndrome (Ritter disease)
Toxic Shock Syndrome

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33
Q

STAPHYLOCOCCUS AUREUS
SPECTRUM OF DISEASE: TOXIGENIC

Gastroenteritis

onset?

vomiting and diarrhea due to ingestion of?

source?

A

acute onset (4 hrs)
preformed heat-stable enterotoxin
salad made with mayonnaise (potato or tuna salad)

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34
Q

STAPHYLOCOCCUS AUREUS
SPECTRUM OF DISEASE: TOXIGENIC

Scalded Skin Syndrome (Ritter disease)

Virulence factor?
Cleaves?
Separation of epidermis at?

A

exfoliatin

cleaves desmoglein in desmosomes

stratum granulosum

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35
Q

TEN (Lyell disease)

Separation of epidermis at?

A

dermo-epidermal junction

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36
Q

STAPHYLOCOCCUS AUREUS
SPECTRUM OF DISEASE: TOXIGENIC

Toxic Shock Syndrome

due to?

fever, hypotension, sloughing of the filiform papillae →

usual scenario?

A

TSST-1

strawberry tongue, desquamating rash and multi-organ
involvement (>3)

tampon-using menstruating women or in patients with nasal packing for epistaxis

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37
Q

TREATMENT
methicillin-sensitive
SA (MSSA)

A

penicillinase-resistant penicillins
(nafcillin, oxacillin, &
dicloxacillin)

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38
Q

TREATMENT
methicillin-resistant
SA (MRSA)

A

contain altered PBP
DOC is vancomycin

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39
Q

TREATMENT
vancomycin-resistant
SA (VRSA)

A

DOC is linezolid

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40
Q

NECROTIZING PNEUMONIA

A

K, VAPS
Kliebsiella (Friedlanders PNM), Viral PNM, Aspergillus,
Pseudomonas (Fleur De Lis), Staphylococcus Aureus

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41
Q

A 12-year-old boy, with a known history of endocarditis,
complains of right leg pain associated with fever. His mother
noticed that her son complains of pain when stepping with his
right foot. X-ray showed a lucency over the distal tibia. Patient was
operated and samples collected intraoperatively was sent for
culture. The most likely organism involved is?
A. Staphylococcus epidermidis
B. Staphylococcus aureus
C. Staphylococcus lugdunensis
D. Streptococcus pyogenes

A

B. Staphylococcus aureus

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42
Q

The radiolucency over the distal tibia described above most likely
represent?
A. Pus collection
B. Tumor growth
C. Fracture
D. Blood collection

A

A. Pus collection

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43
Q

The radiolucency over the distal tibia described above most likely
represent?
A. Pus collection
B. Tumor growth
C. Fracture
D. Blood collection

A

A. Pus collection

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44
Q

A 52/M company manager presented with a 4-week history of
fever, and exertional dyspnea. On physical examination, he had a
grade 3/6 systolic murmur heard loudest over the 3rd ICS left
parasternal border. You also noted splinter hemorrhages under
his fingernails. Which of the following tests will be most helpful in
clinching the diagnosis?
A. Single positive blood culture for S. aureus
B. Echocardiography showing valvular vegetations
C. Elevated ESR and CRP
D. Elevated ASO titers

A

B. Echocardiography showing valvular vegetations

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45
Q

the modified Duke Criteria
• Major criteria:

A

at least 2 (+) cultures
> 12 hours apart,
all 3 or a majority of
>= 4 with the first and last drawn at least 1 hour apart,
single positive blood culture only for Coxiella burnetii

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46
Q

On history, patient admits he actively uses illicit IV drugs. The
most likely organism implicated in this case is?
A. Coxiella burnetii
B. Streptococcus pyogenes
C. Enterococcus spp.
D. S. aureus

A

D. S. aureus

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47
Q

Treatment for the above infection is given for how many days?
A. 10
B. 14
C. 21
D. 28

A

D. 28

generally given for 4-6 weeks to 8 weeks depending
on the factors mentioned

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48
Q

A 14-year-old Caucasian male presents with painful erythematous and honey-
colored crusted lesions around his mouth. Culture of the lesions reveals gram-
positive cocci in clusters. Further analysis reveals bacteria that are beta-
hemolytic, coagulase positive, and appear golden on the blood agar plate.
Which of the following helps the bacterium in this infection bind to
immunoglobulin and prevent phagocytosis when invading its host?
A. Protein A
B. Staphylokinase
C. Exfoliatin A
D. Protein M

A

A. Protein A

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49
Q

Methicillin resistance in Staphylococcus aureus is carried in which gene?
A. blaZ
B. mecA
C. dfrB
D. gyrA

A

B. mecA

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50
Q

gram positive
cocci in clusters
catalase positive,
coagulase negative,
novobiocin sensitive

A

Staphylococcus
epidermidis

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51
Q

gram positive
cocci in clusters

catalase positive,
coagulase negative,
novobiocin resistant

A

Staphylococcus
saprophyticus

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52
Q

STAPHYLOCOCCUS EPIDERMIDIS

• gram-positive cocci in?
• catalase?
• coagulase?
• novobiocin?
• colonies on blood agar?

A

• gram-positive cocci in clusters
• catalase-positive
• coagulase-negative
• novobiocin-sensitive
• whitish, non-hemolytic colonies on blood agar

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53
Q

STAPHYLOCOCCUS EPIDERMIDIS

HABITAT

A

normal skin flora

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54
Q

STAPHYLOCOCCUS AUREUS

TRANSMISSION

A

• direct contact (hands)
• fomites
• contaminated food

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55
Q

STAPHYLOCOCCUS EPIDERMIDIS

TRANSMISSION

A

• autoinfection
• direct contact (hands)

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56
Q

STAPHYLOCOCCUS EPIDERMIDIS

PATHOGENESIS

A

glycocalyx adheres well to foreign bodies and form biofilms

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57
Q

most common cause of
o prosthetic valve endocarditis
o septic arthritis in prosthetic joints
o ventriculoperitoneal shunt infections

A

STAPHYLOCOCCUS EPIDERMIDIS

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58
Q

STAPHYLOCOCCUS EPIDERMIDIS

TREATMENT

A

• removal of prosthetic device
• over 50% are methicillin-resistant and thus require vancomycin

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59
Q

STAPHYLOCOCCUS SAPROPHYTICUS

• gram-positive cocci in?
• catalase?
coagulase?
novobiocin?
• colonies on blood agar?
• Nitrite?

A

• gram-positive cocci in clusters
• catalase-positive, coagulase-negative, novobiocin-resistant
• whitish, non-hemolytic colonies on blood agar
• Nitrite negative (unlike E. coli)

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60
Q

2nd most common cause of UTIs in sexually active women

A

STAPHYLOCOCCUS SAPROPHYTICUS

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61
Q

STAPHYLOCOCCUS SAPROPHYTICUS

CLINICAL FINDINGS

A

• Honeymoon cystitis
• dysuria, pyuria, and bacteriuria

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62
Q

STAPHYLOCOCCUS SAPROPHYTICUS

CLINICAL FINDINGS

A

• Honeymoon cystitis
• dysuria, pyuria, and bacteriuria

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63
Q

STAPHYLOCOCCUS SAPROPHYTICUS

TREATMENT

A

• TMP-SMX, quinolone

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64
Q

STAPHYLOCOCCUS SAPROPHYTICUS

TREATMENT

A

• TMP-SMX, quinolone

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65
Q

Gram-positive cocci in chains

Catalase negative, beta
hemolytic, bacitracin-sensitive

A

Streptococcus pyogenes

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66
Q

STREPTOCOCCUS PYOGENES

• gram-positive cocci in?
• catalase?
• hemolysis?
• bacitracin?
• Lancefield group?
• PYR test?

A

• gram-positive cocci in chains
• catalase-negative
• beta-hemolytic, bacitracin-sensitive
• Lancefield group A
• positive PYR test

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67
Q

measures hydrolysis of l-pyrrolidonyl-β-naphthylamide

A

PYR test

positive result – formation of a red compound

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68
Q

STREPTOCOCCUS PYOGENES
HABITAT

A

• human throat (oropharynx)
• skin

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69
Q

STREPTOCOCCUS PYOGENES
TRANSMISSION

A

respiratory droplets

70
Q

STREPTOCOCCUS PYOGENES

VIRULENCE ENZYMES

A

Hyaluronidase
Streptokinase
(fibrinolysin)
DNase (streptodornase)
C5A peptidase

71
Q

STREPTOCOCCUS PYOGENES

VIRULENCE ENZYMES

A

Hyaluronidase
Streptokinase
(fibrinolysin)
DNase (streptodornase)
C5A peptidase

72
Q

STREPTOCOCCUS PYOGENES

VIRULENCE ENZYMES

degrades hyaluronic acid
(spreading factor)?

activates plasminogen?

degrades DNA in exudates or necrotic tissue?

inactivates complement C5A?

A

Hyaluronidase

Streptokinase
(fibrinolysin)

DNase (streptodornase)

C5A peptidase

73
Q

STREPTOCOCCUS PYOGENES
TOXINS
Erythrogenic toxin produce scarlet fever
Streptolysin O
(oxygen-labile)
highly antigenic
causes AB formation
Streptolysin S (oxygen-stable)
Pyrogenic exotoxin A superantigen similar to TSST
Exotoxin B protease that rapidly destroys
tissue

A

STREPTOCOCCUS PYOGENES
TOXINS
Erythrogenic toxin produce scarlet fever
Streptolysin O
(oxygen-labile)
highly antigenic
causes AB formation
Streptolysin S (oxygen-stable)
Pyrogenic exotoxin A superantigen similar to TSST
Exotoxin B protease that rapidly destroys
tissue

74
Q

STREPTOCOCCUS PYOGENES
TOXINS

A

Erythrogenic toxin
Streptolysin O
(oxygen-labile)
Streptolysin S (oxygen-stable)
Pyrogenic exotoxin A
Exotoxin B

75
Q

STREPTOCOCCUS PYOGENES
TOXINS

produce scarlet fever?

highly antigenic
causes AB formation?

superantigen similar to TSST?

protease that rapidly destroys tissue?

A

Erythrogenic toxin
Streptolysin O
(oxygen-labile)
Streptolysin S (oxygen-stable)
Pyrogenic exotoxin A
Exotoxin B

76
Q

STREPTOCOCCUS PYOGENES
ANTIBODIES

A

Anti-streptolysin O (ASO)
Anti-DNAse B
Anti-streptokinase

77
Q

STREPTOCOCCUS PYOGENES
ANTIBODIES

Elevated titers suggest antecedent
pharyngitis

Elevated titers suggest antecedent skin
infection

Antibodies decrease efficiency of streptokinase in managing MI

A

Anti-streptolysin O
(ASO)
>250 Todd units indicate recent or repeated
infections

Anti-DNAse B

Anti-streptokinase

78
Q

STREPTOCOCCUS PYOGENES

SPECTRUM OF DISEASE: PYOGENIC

A

Skin & Soft Tissue Infections
Impetigo contagiosa
Erysipelas
Cellulitis
Necrotizing fasciitis

Pharyngitis

79
Q

Perioral blistered lesions with honey-colored crust

accumulation of neutrophils beneath?

complication?

A

Impetigo contagiosa

stratum corneum

poststrep GN

80
Q

superficial infection extending into dermal lymphatics

A

Erysipelas

81
Q

deeper infection involving subcutaneous/dermal tissues
facilitated by?

A

Cellulitis

hyaluronidase (spreading factor)

82
Q

rapidly progressive infection of deep subcutaneous tissues

facilitated by?

A

Necrotizing fasciitis
exotoxin B

83
Q

rapidly progressive infection of deep subcutaneous tissues

facilitated by?

A

Necrotizing fasciitis
exotoxin B

84
Q

male genital area and perineum; often caused by mixed organisms
but can be caused by GABHS

A

Fournier’s gangrene

85
Q

most common bacterial cause of sore throat

A

STREPTOCOCCUS PYOGENES

86
Q

STREPTOCOCCUS PYOGENES

Pharyngitis

pyogenic complications:

A

o inflammation, exudate, fever, leukocytosis, and tender CLAD

o pyogenic complications: peritonsillar and retropharyngeal (Quincy)
abscess, otitis, sinusitis, meningitis

87
Q

STREPTOCOCCUS PYOGENES
SPECTRUM OF DISEASE: TOXIGENIC

A

Scarlet Fever

Streptococcal Toxic Shock Syndrome

88
Q

STREPTOCOCCUS PYOGENES
SPECTRUM OF DISEASE: TOXIGENIC

Scarlet Fever

o Post?
o due to?
o clinical findings?
o determining susceptibility to Scarlet Fever?

A

o Post-pharyngitic
o due to erythrogenic toxin, seen in lysogenized strains
o fever, strawberry tongue, centrifugal rash (sandpaper-like), Pastia lines, desquamation
o Dick test –
involves injecting the skin with 0.1 cubic centimeter of
scarlet fever toxin

89
Q

STREPTOCOCCUS PYOGENES
SPECTRUM OF DISEASE: TOXIGENIC

Streptococcal Toxic Shock Syndrome

o clinically similar but milder than?
o due to?
o pyogenic inflammation?
o blood cultures?

A

o clinically similar but milder than S. aureus TSS
o pyrogenic exotoxin A
o recognizable site
o blood cultures are often positive

90
Q

STREPTOCOCCUS PYOGENES
SPECTRUM OF DISEASE: TOXIGENIC

Streptococcal Toxic Shock Syndrome

o clinically similar but milder than?
o due to?
o pyogenic inflammation?
o blood cultures?

A

o clinically similar but milder than S. aureus TSS
o pyrogenic exotoxin A
o recognizable site
o blood cultures are often positive

91
Q

TOXIC SHOCK SYNDROMES

STAPHYLOCOCCAL

Point of infection?
Culture?

A

TSST-1

(-) Point of infection
(-) Culture

92
Q

TOXIC SHOCK SYNDROMES

STREPTOCOCCAL

Point of infection?
Culture?

A

Pyogenic Exo A

(+) Point of infection
(+) Culture

93
Q

STREPTOCOCCUS PYOGENES

SPECTRUM OF DISEASE: IMMUNOLOGIC

A

Acute Rheumatic Fever
Glomerulonephritis

94
Q

STREPTOCOCCUS PYOGENES

SPECTRUM OF DISEASE: IMMUNOLOGIC

Acute Rheumatic Fever

o Post?
o cross-reacting antibodies to?
o marked tendency for?
o Presents with?

A

o Post-pharyngitic (Does not follow streptococcal skin
infections)
o cross-reacting antibodies to M proteins and antigens of joint, heart, and brain tissue
o reactivation with recurrent
streptococcal infections
o migratory polyarthritis and pancarditis

95
Q

J♡NES CRITERIA

A

Joints – polyarthritis
♡ - Carditis
Nodules (subcutaneous)
Erythema marginatum
Sydenham chorea (St. Vitus Dance)

96
Q

STREPTOCOCCUS PYOGENES

SPECTRUM OF DISEASE: IMMUNOLOGIC

Glomerulonephritis

o post?
o M protein incites?
o reactivated by?
o SSx?

A

o post-impetigo (commonly the M12 type) OR post-pharyngitic
o immune complex deposition on the
glomerular basement membrane, type 3
o Not reactivated by recurrent streptococcal infections
o hypertension, periorbital edema, hematuria

97
Q

POST-STREPTOCOCCAL

Glomerulonephritis

Post?
Type?
reactivated?
Chemoprophylaxis?

A

Post SKIN and PHARYNGITIS
Ag-Ab mediated, type 3
NO tendency to be reactivated
Chemoprophylaxis NOT needed

98
Q

POST-STREPTOCOCCAL

Rheumatic fever

Post?
Type?
reactivated?
Chemoprophylaxis?

A

Post PHARYNGITIS only
M protein, type 2
Can be reactivated
Chemoprophylaxis needed

99
Q

Acute Rheumatic Fever

TREATMENT

A

• DOC is Penicillin G
• patients with a history of rheumatic fever require long-term
antibiotic prophylaxis to prevent recurrence of the disease

100
Q

IgG antibodies complexes with self or foreign antigens resulting in complement activation

A

Type 3

101
Q

IgG antibodies complexes with self or foreign antigens resulting in complement activation

A

Type 3

102
Q

Pre-sensitized CD4+ helper T-cell releases cytokines when re-exposed to the offending material

A

Type 4

103
Q

Antigens cross-link IgE antibodies triggering vasoactive amine
release

A

Type 1

104
Q

Cross-reaction of antibodies to bacterial antigens with self-antigens leading to cytotoxicity

A

Type 2

105
Q

sequela caused by rheumatic fever (RF)

A

Aschoff bodies may be found in the heart

Caterpillar cells/ anitschow cells

106
Q

Gram-positive cocci in
chains

Catalase negative, beta
hemolytic, bacitracin-resistant

A

Streptococcus agalactiae

107
Q

STREPTOCOCCUS AGALACTIAE

• gram-positive cocci in?
• Catalase?
• hemolysis?
• Bacitracin?
• Lancefield group?
• hippurate?
• CAMP test?
• grow using?

A

• chains
• Catalase negative
• Beta-hemolytic
• Bacitracin-resistant
• Lancefield group B
• hydrolyze hippurate, +
• CAMP test–positive
• Lim broth

108
Q

CAMP test

Meaning?
(+) result?
Where?

A

Christie, Atkins,
Munch-Petersen test

arrowhead shaped zone of hemolysis

perpendicular to S. aureus
streak

109
Q

STREPTOCOCCUS AGALACTIAE

HABITAT

A

vagina

110
Q

STREPTOCOCCUS AGALACTIAE

TRANSMISSION

A

• transvaginal
• transplacental

111
Q

STREPTOCOCCUS AGALACTIAE

SPECTRUM OF DISEASE

A

• urinary tract infection in pregnant women
• neonatal pneumonia, sepsis and meningitis

112
Q

most common cause of neonatal pneumonia, sepsis and meningitis

A

STREPTOCOCCUS AGALACTIAE

113
Q

STREPTOCOCCUS AGALACTIAE

neonatal pneumonia, sepsis and meningitis

predisposing factors?

A

§ intrapartum fever (T>38)
§ PROM (>18h)
§ vaginal colonization
§ complement deficiency
§ endometritis

114
Q

Neonatal Meningitis
Top 3

A

S. agalactiae
L. monocytogenes
E. coli

115
Q

STREPTOCOCCUS AGALACTIAE

TREATMENT

A

DOC is penicillin G

116
Q

all pregnant women should be screened for GBS colonization
at?

chemoprophylaxis with?

A

35-37 weeks AOG

IV Penicillin or Ampicillin 4 hours prior to delivery

117
Q

Gram-positive cocci in
chains

Catalase negative, gamma
hemolytic

A

Group D streptococci

118
Q

GROUP D STREPTOCOCCI

• gram-positive cocci?
• catalase?
• hemolysis?
• Lancefield group?
• Growth in?
hydrolyzes?
in medium?

A

• chains
• catalase-negative
• gamma hemolytic colonies
• Lancefield group D
• Growth in bile,
hydrolyzes esculin
in bile-esculin agar (BEA)

119
Q

GROUP D STREPTOCOCCI

• gram-positive cocci?
• catalase?
• hemolysis?
• Lancefield group?
• Growth in?
hydrolyzes?
in medium?

A

• chains
• catalase-negative
• gamma hemolytic colonies
• Lancefield group D
• Growth in bile,
hydrolyzes esculin
in bile-esculin agar (BEA)

120
Q

ENTEROCOCCI

PYR test?
Growth in 6.5% NaCl?

A

PYR test - Positive
Growth in 6.5% NaCl - Positive

121
Q

S. BOVIS

PYR test?
Growth in 6.5% NaCl?

A

PYR test - Negative
Growth in 6.5% NaCl - Negative

122
Q

S. BOVIS

PYR test?
Growth in 6.5% NaCl?

A
123
Q

GROUP D STREPTOCOCCI

HABITAT

A

• human colon
• urethra and female genital tract can be colonized

124
Q

GROUP D STREPTOCOCCI

TRANSMISSION

A

may enter bloodstream during gastrointestinal (GI) or genitourinary tract procedures

125
Q

GROUP D STREPTOCOCCI

SPECTRUM OF DISEASES

A

UTIs due to indwelling urinary catheters and urinary tract
instrumentation

biliary tract infections

endocarditis

126
Q

endocarditis in patients who underwent GIT surgery

A

E. faecalis

127
Q

GROUP D STREPTOCOCCI

TREATMENT

for penicillin-resistance?
for vancomycin-resistant strains?

A

• Penicillin plus gentamicin
• Vancomycin for penicillin-resistance
• Linezolid for vancomycin-resistant strains

128
Q

endocarditis in patients with abdominal malignancy
due to?
what endocarditis?

A

S. bovis

Marantic endocarditis

129
Q

Gram-positive cocci in
chains Catalase negative, alpha hemolytic, bile soluble, optochin-sensitive
Taxo P

A

Streptococcus
pneumoniae

130
Q

Gram- positive cocci in
chains
Catalase negative, alpha
hemolytic, bile insoluble,
optochin-resistant

A

viridans streptococcal sp.

131
Q

Gram- positive cocci in
chains
Catalase negative, alpha
hemolytic, bile insoluble,
optochin-resistant

A

viridans streptococcal sp.

132
Q

STREPTOCOCCUS PNEUMONIAE

• Gram-positive cocci in?
• Catalase?
• hemolysis?
• Bile soluble and optochin?
• Quellung reaction

A

• Gram-positive “lancet-shaped” cocci in pairs or chains
• Catalase-negative
• Alpha-hemolytic
• Bile soluble and optochin-sensitive
• positive Quellung reaction

133
Q

STREPTOCOCCUS PNEUMONIAE

HABITAT AND TRANSMISSION

A

• habitat is upper respiratory tract
• transmission via respiratory droplets

134
Q

STREPTOCOCCUS PNEUMONIAE

PATHOGENESIS

retards phagocytosis?
for colonization?
reacts with CRP?

A

capsule retards phagocytosis
IgA protease for colonization
c-substance reacts with CRP

135
Q

STREPTOCOCCUS PNEUMONIAE

SPECTRUM OF DISEASES: PYOGENIC

A

Pneumonia
Otitis media, sinusitis, meningitis
Septic shock

136
Q

most common cause of CAP
o Blood-tinged, pink, or rusty sputum
o Blood cultures often positive

A

STREPTOCOCCUS PNEUMONIAE

137
Q

predisposes to sepsis?

Bacteria?

A

Splenectomy

S. Pneumoniae
N. Meningitidis
H.influenzae

138
Q

STREPTOCOCCUS PNEUMONIAE

TREATMENT

A

• Penicillin G
• Levofloxacin or Vancomycin combined with Ceftriaxone for
penicillin resistance

139
Q

STREPTOCOCCUS PNEUMONIAE

PREVENTION

A

polysaccharide vaccine
conjugated vaccine

140
Q

Most common cause of otitis media

A

STREPTOCOCCUS PNEUMONIAE

141
Q

Most common cause of adult meningitis

A

STREPTOCOCCUS PNEUMONIAE

142
Q

E. VIRIDANS STREPTOCOCCI
REPRESENTATIVE SPECIES

A

• S. mutans
• S. mitis
• S. sanguis
• S. salivarius
• S. anginosus

143
Q

VIRIDANS STREPTOCOCCI

gram-positive cocci?
• Catalase-?
• hemolysis?
• Bile insoluble and optochin?

A

gram-positive cocci in chains
• Catalase-negative
• Alpha-hemolytic
• Bile insoluble and optochin-resistant

144
Q

VIRIDANS STREPTOCOCCI

HABITAT AND TRANSMISSION

A

oropharynx

bloodstream during dental procedures

145
Q

VIRIDANS

PATHOGENESIS

A

glycocalyx enhances adhesion to damaged heart valves
• protected from host defenses within vegetations

146
Q

VIRIDANS STREPTOCOCCI

for dental caries

A

S. mutans

147
Q

VIRIDANS STREPTOCOCCI

for subacute bacterial endocarditis (SBE)

most common cause of subacute and native valve endocarditis

A

S. sanguis

148
Q

VIRIDANS STREPTOCOCCI

for brain abscesses

A

S. intermedius

149
Q

VIRIDANS STREPTOCOCCI

TREATMENT

for penicillin-resistance

vancomycin-resistant strains

A

Penicillin G with or without an aminoglycoside (Gentamicin)

Vancomycin

Linezolid

150
Q

grows around
colonies of S. aureus

A

Satelliting streptococci

NUTRITIONALLY VARIANT STREPTOCOCCI

151
Q

grows around
colonies of S. aureus

A

Satelliting streptococci

NUTRITIONALLY VARIANT STREPTOCOCCI

152
Q

NUTRITIONALLY VARIANT STREPTOCOCCI

Includes 2 genera:

A

Abiotrophia and Granulicatella

153
Q

NUTRITIONALLY VARIANT STREPTOCOCCI

Requires for growth

A

cysteine or pyridoxal (Vitamin B6)

154
Q

NUTRITIONALLY VARIANT STREPTOCOCCI

Normal flora of

A

human oral cavity

155
Q

NUTRITIONALLY VARIANT STREPTOCOCCI

Normal flora of

A

human oral cavity

156
Q

NUTRITIONALLY VARIANT STREPTOCOCCI

implicated in?

Susceptible to?

A

endocarditis

vancomycin

157
Q

PEPTOSTREPTOCOCCUS

Grows only under what conditions?
Normal flora of?
Produces?
Clinical manifestations?

A

anaerobic or microaerophilic

the oral cavity, upper respiratory tract, bowel,
and female genital tract

pus with foul odor

postpartum endometritis, chronic suppuration of the lung, after rupture of an abdominal viscus,
wound infections

158
Q

Cefalexin may be useful to treat which infection?

A. Enterococcal endocarditis
B. Listerial meningitis
C. MRSA pneumonia
D. Hidradenitis suppurativa
E. All of the above

A

D. Hidradenitis suppurativa

159
Q

Toxic looking
No underlying heart problem
Native valve/Prosthetic valve

A

Acute Endocarditis

160
Q

With underlying heart problem
Gradual development
Native valve/Prosthetic valve

A

Subacute Endocarditis

161
Q

Acute endocarditis
Native valve

A

S. Aureus

162
Q

Acute endocarditis
Prosthetic valve

A

S. Epidermidis

163
Q

Subacute endocarditis
Native/Prosthetic

A

Viridans sp.

164
Q

Endocarditis after GIT surgery

A

E. Faecalis/ Enterococcus

165
Q

Marantic endocarditis
Sterile
Risk for GIT neoplasm

A

S. Bovis

166
Q

A 34 year old male from Tondo, Manila, an IV heroin user, presents with a 3 day history of fever T>39, chest pain, character; nausea, vomiting. Troponins are low. CKMB negative. PMHx: tricuspid valve repair in 2003. What is the most likely diagnosis?

a. Acute endocarditis
b. Subacute endocarditis
c. Myocarditis
d. Takotsubo cardiomyopathy

A

a. Acute endocarditis

167
Q

In relation to the case above, which is true regarding the causative agent? Acute endocarditis
a. Gram negative bacilli
b. Coagulase negative
c. Optochin resistant
d. Inhibited by Novobiocin

A

b. Coagulase negative

d. Inhibited by Novobiocin

168
Q

In the above case, what in the cardiac physical examination is
MOST LIKELY noted?
a. Dynamic precordium
b. (+) muffled heart sounds
c. Diastolic murmur
d. Holosystolic murmur

A

d. Holosystolic murmur

169
Q

A 34 year old male from Tondo, Manila, a heroin user, presents with sudden onset of fever T> 39, RLQ pain, nausea, vomiting.
Emergency appendectomy was done. 2 days post-op, (+) pinching chest pain. Troponins are low. CKMB negative. ECG shows sinus
tachycardia. Blood culture on 2 sites were positive. (+) bacterial vegetations on tricuspid area seen in TEE. What is the most likely causative agent?
a. Staphylococcus epidermidis
b. Staphylococcus aureus
c. Clostridium spp.
d. Enterococcus spp.

A

d. Enterococcus spp.

170
Q

A 34 year old male from T ondo, Manila, a heroin user, presents with sudden onset of fever T> 39, vague abdominal pain, nausea, vomiting. Emergency laparotomy was done. Diagnosis of colon
cancer was noted. 2 days post-op, (+) pinching chest pain. Troponins are low. CKMB negative. ECG shows sinus tachycardia.
Blood culture on 2 sites were negative. (+) sterile vegetations on tricuspid area seen in TEE. What is the most likely causative
agent?
a. Staphylococcus epidermidis
b. Staphylococcus aureus
c. Streptococcus bovis
d. Enterococcus spp.

A

c. Streptococcus bovis

03 (4 decks)

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