M2.1 Flashcards
1
Q
gram positive cocci in clusters
catalase positive, coagulase positive
A
Staphylococcus aureus
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
3
Q
STAPHYLOCOCCUS AUREUS
HABITAT
A
human nose (anterior nares) and skin
4
Q
STAPHYLOCOCCUS AUREUS
VIRULENCE FACTORS:
IMMUNOMODULATORS
A
Protein A
Coagulase
Hemolysins (cytotoxins)
PV Leukocidin
Catalase
Penicillinase
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
6
Q
STAPHYLOCOCCUS AUREUS
VIRULENCE FACTORS:
TISSUE PENETRANCE
A
Hyaluronidase
Fibrinolysin
(staphylokinase)
Lipase
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
8
Q
STAPHYLOCOCCUS AUREUS
VIRULENCE FACTORS:
TOXINS (4)
A
Exfoliatin A and B
Enterotoxins (heat-stable)
Toxic shock syndrome toxin (TSST-1)
Alpha toxin
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
10
Q
virulence factor that helps S. aureus evade the immune system early in infection
A
coagulase
11
Q
factor involved in spreading the infection or breaking down clots later in the infection
A
fibrinolysin (staphylokinase)
12
Q
Exofoliatin Toxin
causes epidermal separation on what layer?
what disease?
cleaves?
A
stratum granulosum
Scalded Skin Syndrome (aka Ritter Disease)
Desmoglein
13
Q
Enterotoxin
Common food sources:
incubation period:
A
Heat stable
poultry, ham, meat, potato salad
Short, 1-8/ 1-6 hrs
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
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
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
17
Q
STAPHYLOCOCCUS AUREUS
SPECTRUM OF DISEASE: PYOGENIC
A
Skin & Soft Tissue Infections
Acute Endocarditis
Osteomyelitis & Septic Arthritis
18
Q
STAPHYLOCOCCUS AUREUS
DISEASE: PYOGENIC
• Skin & Soft Tissue Infections
A
- bullous impetigo
- folliculitis
- furuncles
- carbuncles
- cellulitis
- hidradenitis suppurativa
- mastitis
- surgical site infections
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
20
Q
Most common cause of acute endocarditis
o native valve (tricuspid valve) in IV drug users
A
Staphylococcus aureus
21
Q
Most common cause of acute endocarditis
o native valve (tricuspid valve) in IV drug users
A
Staphylococcus aureus
22
Q
INFECTIVE ENDOCARDITIS IN IV Drug user:
A
Staphylococcus aureus
23
Q
INFECTIVE ENDOCARDITIS IN
Prosthetic valve:
A
Staphylococcus epidermidis
24
Q
INFECTIVE ENDOCARDITIS IN s/p GU or GI procedures:
A
Enterococcus Faecalis
25
INFECTIVE ENDOCARDITIS IN(+) GI Malignancy:
Streptococcus bovis
26
INFECTIVE ENDOCARDITIS IN(+) GI Malignancy:
Streptococcus bovis
27
INFECTIVE ENDOCARDITIS IN Dental procedures:
Viridans streptococcus
28
INFECTIVE ENDOCARDITIS
most frequent valve involved in IV drug user
Tricuspid Valve
29
INFECTIVE ENDOCARDITIS most frequent valve involved EXCEPT in IV drug user
Mitral Valve
30
STAPHYLOCOCCUS AUREUS
DISEASE: PYOGENIC
Pneumonia
1. nosocomial pneumonia
2. VAP
3. necrotizing pneumonia
4. post-viral pneumonia
complicated by empyema, abscess or pneumatocele
31
STAPHYLOCOCCUS AUREUS
Osteomyelitis & Septic Arthritis
Spread?
involves in children?
more common in adults?
Abscess?
sequestered focus of osteomyelitis arising in the?
hematogenous spread or direct inoculation
long bones
vertebral osteomyelitis
Brodie abscess
metaphyseal area of a long bone
32
STAPHYLOCOCCUS AUREUS
SPECTRUM OF DISEASE: TOXIGENIC
Gastroenteritis
Scalded Skin Syndrome (Ritter disease)
Toxic Shock Syndrome
33
STAPHYLOCOCCUS AUREUS
SPECTRUM OF DISEASE: TOXIGENIC
Gastroenteritis
onset?
vomiting and diarrhea due to ingestion of?
source?
acute onset (4 hrs)
preformed heat-stable enterotoxin
salad made with mayonnaise (potato or tuna salad)
34
STAPHYLOCOCCUS AUREUS
SPECTRUM OF DISEASE: TOXIGENIC
Scalded Skin Syndrome (Ritter disease)
Virulence factor?
Cleaves?
Separation of epidermis at?
exfoliatin
cleaves desmoglein in desmosomes
stratum granulosum
35
TEN (Lyell disease)
Separation of epidermis at?
dermo-epidermal junction
36
STAPHYLOCOCCUS AUREUS
SPECTRUM OF DISEASE: TOXIGENIC
Toxic Shock Syndrome
due to?
fever, hypotension, sloughing of the filiform papillae →
usual scenario?
TSST-1
strawberry tongue, desquamating rash and multi-organ
involvement (>3)
tampon-using menstruating women or in patients with nasal packing for epistaxis
37
TREATMENT
methicillin-sensitive
SA (MSSA)
penicillinase-resistant penicillins
(nafcillin, oxacillin, &
dicloxacillin)
38
TREATMENT
methicillin-resistant
SA (MRSA)
contain altered PBP
DOC is vancomycin
39
TREATMENT
vancomycin-resistant
SA (VRSA)
DOC is linezolid
40
NECROTIZING PNEUMONIA
K, VAPS
Kliebsiella (Friedlanders PNM), Viral PNM, Aspergillus,
Pseudomonas (Fleur De Lis), Staphylococcus Aureus
41
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
B. Staphylococcus aureus
42
The radiolucency over the distal tibia described above most likely
represent?
A. Pus collection
B. Tumor growth
C. Fracture
D. Blood collection
A. Pus collection
43
The radiolucency over the distal tibia described above most likely
represent?
A. Pus collection
B. Tumor growth
C. Fracture
D. Blood collection
A. Pus collection
44
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
B. Echocardiography showing valvular vegetations
45
the modified Duke Criteria
• Major criteria:
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
46
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
D. S. aureus
47
Treatment for the above infection is given for how many days?
A. 10
B. 14
C. 21
D. 28
D. 28
generally given for 4-6 weeks to 8 weeks depending
on the factors mentioned
48
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. Protein A
49
Methicillin resistance in Staphylococcus aureus is carried in which gene?
A. blaZ
B. mecA
C. dfrB
D. gyrA
B. mecA
50
gram positive
cocci in clusters
catalase positive,
coagulase negative,
novobiocin sensitive
Staphylococcus
epidermidis
51
gram positive
cocci in clusters
catalase positive,
coagulase negative,
novobiocin resistant
Staphylococcus
saprophyticus
52
STAPHYLOCOCCUS EPIDERMIDIS
• gram-positive cocci in?
• catalase?
• coagulase?
• novobiocin?
• colonies on blood agar?
• gram-positive cocci in clusters
• catalase-positive
• coagulase-negative
• novobiocin-sensitive
• whitish, non-hemolytic colonies on blood agar
53
STAPHYLOCOCCUS EPIDERMIDIS
HABITAT
normal skin flora
54
STAPHYLOCOCCUS AUREUS
TRANSMISSION
• direct contact (hands)
• fomites
• contaminated food
55
STAPHYLOCOCCUS EPIDERMIDIS
TRANSMISSION
• autoinfection
• direct contact (hands)
56
STAPHYLOCOCCUS EPIDERMIDIS
PATHOGENESIS
glycocalyx adheres well to foreign bodies and form biofilms
57
most common cause of
o prosthetic valve endocarditis
o septic arthritis in prosthetic joints
o ventriculoperitoneal shunt infections
STAPHYLOCOCCUS EPIDERMIDIS
58
STAPHYLOCOCCUS EPIDERMIDIS
TREATMENT
• removal of prosthetic device
• over 50% are methicillin-resistant and thus require vancomycin
59
STAPHYLOCOCCUS SAPROPHYTICUS
• gram-positive cocci in?
• catalase?
coagulase?
novobiocin?
• colonies on blood agar?
• Nitrite?
• gram-positive cocci in clusters
• catalase-positive, coagulase-negative, novobiocin-resistant
• whitish, non-hemolytic colonies on blood agar
• Nitrite negative (unlike E. coli)
60
2nd most common cause of UTIs in sexually active women
STAPHYLOCOCCUS SAPROPHYTICUS
61
STAPHYLOCOCCUS SAPROPHYTICUS
CLINICAL FINDINGS
• Honeymoon cystitis
• dysuria, pyuria, and bacteriuria
62
STAPHYLOCOCCUS SAPROPHYTICUS
CLINICAL FINDINGS
• Honeymoon cystitis
• dysuria, pyuria, and bacteriuria
63
STAPHYLOCOCCUS SAPROPHYTICUS
TREATMENT
• TMP-SMX, quinolone
64
STAPHYLOCOCCUS SAPROPHYTICUS
TREATMENT
• TMP-SMX, quinolone
65
Gram-positive cocci in chains
Catalase negative, beta
hemolytic, bacitracin-sensitive
Streptococcus pyogenes
66
STREPTOCOCCUS PYOGENES
• gram-positive cocci in?
• catalase?
• hemolysis?
• bacitracin?
• Lancefield group?
• PYR test?
• gram-positive cocci in chains
• catalase-negative
• beta-hemolytic, bacitracin-sensitive
• Lancefield group A
• positive PYR test
67
measures hydrolysis of l-pyrrolidonyl-β-naphthylamide
PYR test
positive result – formation of a red compound
68
STREPTOCOCCUS PYOGENES
HABITAT
• human throat (oropharynx)
• skin
69
STREPTOCOCCUS PYOGENES
TRANSMISSION
respiratory droplets
70
STREPTOCOCCUS PYOGENES
VIRULENCE ENZYMES
Hyaluronidase
Streptokinase
(fibrinolysin)
DNase (streptodornase)
C5A peptidase
71
STREPTOCOCCUS PYOGENES
VIRULENCE ENZYMES
Hyaluronidase
Streptokinase
(fibrinolysin)
DNase (streptodornase)
C5A peptidase
72
STREPTOCOCCUS PYOGENES
VIRULENCE ENZYMES
degrades hyaluronic acid
(spreading factor)?
activates plasminogen?
degrades DNA in exudates or necrotic tissue?
inactivates complement C5A?
Hyaluronidase
Streptokinase
(fibrinolysin)
DNase (streptodornase)
C5A peptidase
73
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
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
STREPTOCOCCUS PYOGENES
TOXINS
Erythrogenic toxin
Streptolysin O
(oxygen-labile)
Streptolysin S (oxygen-stable)
Pyrogenic exotoxin A
Exotoxin B
75
STREPTOCOCCUS PYOGENES
TOXINS
produce scarlet fever?
highly antigenic
causes AB formation?
superantigen similar to TSST?
protease that rapidly destroys tissue?
Erythrogenic toxin
Streptolysin O
(oxygen-labile)
Streptolysin S (oxygen-stable)
Pyrogenic exotoxin A
Exotoxin B
76
STREPTOCOCCUS PYOGENES
ANTIBODIES
Anti-streptolysin O (ASO)
Anti-DNAse B
Anti-streptokinase
77
STREPTOCOCCUS PYOGENES
ANTIBODIES
Elevated titers suggest antecedent
pharyngitis
Elevated titers suggest antecedent skin
infection
Antibodies decrease efficiency of streptokinase in managing MI
Anti-streptolysin O
(ASO)
>250 Todd units indicate recent or repeated
infections
Anti-DNAse B
Anti-streptokinase
78
STREPTOCOCCUS PYOGENES
SPECTRUM OF DISEASE: PYOGENIC
Skin & Soft Tissue Infections
Impetigo contagiosa
Erysipelas
Cellulitis
Necrotizing fasciitis
Pharyngitis
79
Perioral blistered lesions with honey-colored crust
accumulation of neutrophils beneath?
complication?
Impetigo contagiosa
stratum corneum
poststrep GN
80
superficial infection extending into dermal lymphatics
Erysipelas
81
deeper infection involving subcutaneous/dermal tissues
facilitated by?
Cellulitis
hyaluronidase (spreading factor)
82
rapidly progressive infection of deep subcutaneous tissues
facilitated by?
Necrotizing fasciitis
exotoxin B
83
rapidly progressive infection of deep subcutaneous tissues
facilitated by?
Necrotizing fasciitis
exotoxin B
84
male genital area and perineum; often caused by mixed organisms
but can be caused by GABHS
Fournier's gangrene
85
most common bacterial cause of sore throat
STREPTOCOCCUS PYOGENES
86
STREPTOCOCCUS PYOGENES
Pharyngitis
pyogenic complications:
o inflammation, exudate, fever, leukocytosis, and tender CLAD
o pyogenic complications: peritonsillar and retropharyngeal (Quincy)
abscess, otitis, sinusitis, meningitis
87
STREPTOCOCCUS PYOGENES
SPECTRUM OF DISEASE: TOXIGENIC
Scarlet Fever
Streptococcal Toxic Shock Syndrome
88
STREPTOCOCCUS PYOGENES
SPECTRUM OF DISEASE: TOXIGENIC
Scarlet Fever
o Post?
o due to?
o clinical findings?
o determining susceptibility to Scarlet Fever?
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
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?
o clinically similar but milder than S. aureus TSS
o pyrogenic exotoxin A
o recognizable site
o blood cultures are often positive
90
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?
o clinically similar but milder than S. aureus TSS
o pyrogenic exotoxin A
o recognizable site
o blood cultures are often positive
91
TOXIC SHOCK SYNDROMES
STAPHYLOCOCCAL
Point of infection?
Culture?
TSST-1
(-) Point of infection
(-) Culture
92
TOXIC SHOCK SYNDROMES
STREPTOCOCCAL
Point of infection?
Culture?
Pyogenic Exo A
(+) Point of infection
(+) Culture
93
STREPTOCOCCUS PYOGENES
SPECTRUM OF DISEASE: IMMUNOLOGIC
Acute Rheumatic Fever
Glomerulonephritis
94
STREPTOCOCCUS PYOGENES
SPECTRUM OF DISEASE: IMMUNOLOGIC
Acute Rheumatic Fever
o Post?
o cross-reacting antibodies to?
o marked tendency for?
o Presents with?
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
J♡NES CRITERIA
Joints – polyarthritis
♡ - Carditis
Nodules (subcutaneous)
Erythema marginatum
Sydenham chorea (St. Vitus Dance)
96
STREPTOCOCCUS PYOGENES
SPECTRUM OF DISEASE: IMMUNOLOGIC
Glomerulonephritis
o post?
o M protein incites?
o reactivated by?
o SSx?
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
POST-STREPTOCOCCAL
Glomerulonephritis
Post?
Type?
reactivated?
Chemoprophylaxis?
Post SKIN and PHARYNGITIS
Ag-Ab mediated, type 3
NO tendency to be reactivated
Chemoprophylaxis NOT needed
98
POST-STREPTOCOCCAL
Rheumatic fever
Post?
Type?
reactivated?
Chemoprophylaxis?
Post PHARYNGITIS only
M protein, type 2
Can be reactivated
Chemoprophylaxis needed
99
Acute Rheumatic Fever
TREATMENT
• DOC is Penicillin G
• patients with a history of rheumatic fever require long-term
antibiotic prophylaxis to prevent recurrence of the disease
100
IgG antibodies complexes with self or foreign antigens resulting in complement activation
Type 3
101
IgG antibodies complexes with self or foreign antigens resulting in complement activation
Type 3
102
Pre-sensitized CD4+ helper T-cell releases cytokines when re-exposed to the offending material
Type 4
103
Antigens cross-link IgE antibodies triggering vasoactive amine
release
Type 1
104
Cross-reaction of antibodies to bacterial antigens with self-antigens leading to cytotoxicity
Type 2
105
sequela caused by rheumatic fever (RF)
Aschoff bodies may be found in the heart
Caterpillar cells/ anitschow cells
106
Gram-positive cocci in
chains
Catalase negative, beta
hemolytic, bacitracin-resistant
Streptococcus agalactiae
107
STREPTOCOCCUS AGALACTIAE
• gram-positive cocci in?
• Catalase?
• hemolysis?
• Bacitracin?
• Lancefield group?
• hippurate?
• CAMP test?
• grow using?
• chains
• Catalase negative
• Beta-hemolytic
• Bacitracin-resistant
• Lancefield group B
• hydrolyze hippurate, +
• CAMP test–positive
• Lim broth
108
CAMP test
Meaning?
(+) result?
Where?
Christie, Atkins,
Munch-Petersen test
arrowhead shaped zone of hemolysis
perpendicular to S. aureus
streak
109
STREPTOCOCCUS AGALACTIAE
HABITAT
vagina
110
STREPTOCOCCUS AGALACTIAE
TRANSMISSION
• transvaginal
• transplacental
111
STREPTOCOCCUS AGALACTIAE
SPECTRUM OF DISEASE
• urinary tract infection in pregnant women
• neonatal pneumonia, sepsis and meningitis
112
most common cause of neonatal pneumonia, sepsis and meningitis
STREPTOCOCCUS AGALACTIAE
113
STREPTOCOCCUS AGALACTIAE
neonatal pneumonia, sepsis and meningitis
predisposing factors?
§ intrapartum fever (T>38)
§ PROM (>18h)
§ vaginal colonization
§ complement deficiency
§ endometritis
114
Neonatal Meningitis
Top 3
S. agalactiae
L. monocytogenes
E. coli
115
STREPTOCOCCUS AGALACTIAE
TREATMENT
DOC is penicillin G
116
all pregnant women should be screened for GBS colonization
at?
chemoprophylaxis with?
35-37 weeks AOG
IV Penicillin or Ampicillin 4 hours prior to delivery
117
Gram-positive cocci in
chains
Catalase negative, gamma
hemolytic
Group D streptococci
118
GROUP D STREPTOCOCCI
• gram-positive cocci?
• catalase?
• hemolysis?
• Lancefield group?
• Growth in?
hydrolyzes?
in medium?
• chains
• catalase-negative
• gamma hemolytic colonies
• Lancefield group D
• Growth in bile,
hydrolyzes esculin
in bile-esculin agar (BEA)
119
GROUP D STREPTOCOCCI
• gram-positive cocci?
• catalase?
• hemolysis?
• Lancefield group?
• Growth in?
hydrolyzes?
in medium?
• chains
• catalase-negative
• gamma hemolytic colonies
• Lancefield group D
• Growth in bile,
hydrolyzes esculin
in bile-esculin agar (BEA)
120
ENTEROCOCCI
PYR test?
Growth in 6.5% NaCl?
PYR test - Positive
Growth in 6.5% NaCl - Positive
121
S. BOVIS
PYR test?
Growth in 6.5% NaCl?
PYR test - Negative
Growth in 6.5% NaCl - Negative
122
S. BOVIS
PYR test?
Growth in 6.5% NaCl?
123
GROUP D STREPTOCOCCI
HABITAT
• human colon
• urethra and female genital tract can be colonized
124
GROUP D STREPTOCOCCI
TRANSMISSION
may enter bloodstream during gastrointestinal (GI) or genitourinary tract procedures
125
GROUP D STREPTOCOCCI
SPECTRUM OF DISEASES
UTIs due to indwelling urinary catheters and urinary tract
instrumentation
biliary tract infections
endocarditis
126
endocarditis in patients who underwent GIT surgery
E. faecalis
127
GROUP D STREPTOCOCCI
TREATMENT
for penicillin-resistance?
for vancomycin-resistant strains?
• Penicillin plus gentamicin
• Vancomycin for penicillin-resistance
• Linezolid for vancomycin-resistant strains
128
endocarditis in patients with abdominal malignancy
due to?
what endocarditis?
S. bovis
Marantic endocarditis
129
Gram-positive cocci in
chains Catalase negative, alpha hemolytic, bile soluble, optochin-sensitive
Taxo P
Streptococcus
pneumoniae
130
Gram- positive cocci in
chains
Catalase negative, alpha
hemolytic, bile insoluble,
optochin-resistant
viridans streptococcal sp.
131
Gram- positive cocci in
chains
Catalase negative, alpha
hemolytic, bile insoluble,
optochin-resistant
viridans streptococcal sp.
132
STREPTOCOCCUS PNEUMONIAE
• Gram-positive cocci in?
• Catalase?
• hemolysis?
• Bile soluble and optochin?
• Quellung reaction
• Gram-positive "lancet-shaped" cocci in pairs or chains
• Catalase-negative
• Alpha-hemolytic
• Bile soluble and optochin-sensitive
• positive Quellung reaction
133
STREPTOCOCCUS PNEUMONIAE
HABITAT AND TRANSMISSION
• habitat is upper respiratory tract
• transmission via respiratory droplets
134
STREPTOCOCCUS PNEUMONIAE
PATHOGENESIS
retards phagocytosis?
for colonization?
reacts with CRP?
capsule retards phagocytosis
IgA protease for colonization
c-substance reacts with CRP
135
STREPTOCOCCUS PNEUMONIAE
SPECTRUM OF DISEASES: PYOGENIC
Pneumonia
Otitis media, sinusitis, meningitis
Septic shock
136
most common cause of CAP
o Blood-tinged, pink, or rusty sputum
o Blood cultures often positive
STREPTOCOCCUS PNEUMONIAE
137
predisposes to sepsis?
Bacteria?
Splenectomy
S. Pneumoniae
N. Meningitidis
H.influenzae
138
STREPTOCOCCUS PNEUMONIAE
TREATMENT
• Penicillin G
• Levofloxacin or Vancomycin combined with Ceftriaxone for
penicillin resistance
139
STREPTOCOCCUS PNEUMONIAE
PREVENTION
polysaccharide vaccine
conjugated vaccine
140
Most common cause of otitis media
STREPTOCOCCUS PNEUMONIAE
141
Most common cause of adult meningitis
STREPTOCOCCUS PNEUMONIAE
142
E. VIRIDANS STREPTOCOCCI
REPRESENTATIVE SPECIES
• S. mutans
• S. mitis
• S. sanguis
• S. salivarius
• S. anginosus
143
VIRIDANS STREPTOCOCCI
gram-positive cocci?
• Catalase-?
• hemolysis?
• Bile insoluble and optochin?
gram-positive cocci in chains
• Catalase-negative
• Alpha-hemolytic
• Bile insoluble and optochin-resistant
144
VIRIDANS STREPTOCOCCI
HABITAT AND TRANSMISSION
oropharynx
bloodstream during dental procedures
145
VIRIDANS
PATHOGENESIS
glycocalyx enhances adhesion to damaged heart valves
• protected from host defenses within vegetations
146
VIRIDANS STREPTOCOCCI
for dental caries
S. mutans
147
VIRIDANS STREPTOCOCCI
for subacute bacterial endocarditis (SBE)
most common cause of subacute and native valve endocarditis
S. sanguis
148
VIRIDANS STREPTOCOCCI
for brain abscesses
S. intermedius
149
VIRIDANS STREPTOCOCCI
TREATMENT
for penicillin-resistance
vancomycin-resistant strains
Penicillin G with or without an aminoglycoside (Gentamicin)
Vancomycin
Linezolid
150
grows around
colonies of S. aureus
Satelliting streptococci
NUTRITIONALLY VARIANT STREPTOCOCCI
151
grows around
colonies of S. aureus
Satelliting streptococci
NUTRITIONALLY VARIANT STREPTOCOCCI
152
NUTRITIONALLY VARIANT STREPTOCOCCI
Includes 2 genera:
Abiotrophia and Granulicatella
153
NUTRITIONALLY VARIANT STREPTOCOCCI
Requires for growth
cysteine or pyridoxal (Vitamin B6)
154
NUTRITIONALLY VARIANT STREPTOCOCCI
Normal flora of
human oral cavity
155
NUTRITIONALLY VARIANT STREPTOCOCCI
Normal flora of
human oral cavity
156
NUTRITIONALLY VARIANT STREPTOCOCCI
implicated in?
Susceptible to?
endocarditis
vancomycin
157
PEPTOSTREPTOCOCCUS
Grows only under what conditions?
Normal flora of?
Produces?
Clinical manifestations?
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
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
D. Hidradenitis suppurativa
159
Toxic looking
No underlying heart problem
Native valve/Prosthetic valve
Acute Endocarditis
160
With underlying heart problem
Gradual development
Native valve/Prosthetic valve
Subacute Endocarditis
161
Acute endocarditis
Native valve
S. Aureus
162
Acute endocarditis
Prosthetic valve
S. Epidermidis
163
Subacute endocarditis
Native/Prosthetic
Viridans sp.
164
Endocarditis after GIT surgery
E. Faecalis/ Enterococcus
165
Marantic endocarditis
Sterile
Risk for GIT neoplasm
S. Bovis
166
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. Acute endocarditis
167
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
b. Coagulase negative
d. Inhibited by Novobiocin
168
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
d. Holosystolic murmur
169
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.
d. Enterococcus spp.
170
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.
c. Streptococcus bovis
