Streptococci Flashcards
1
Q
Strip of bacteria looking like chains
Catalase ?
A
Streptococci
-
2
Q
Differentiates strep species
A
Hemolysis
3
Q
Catalase - Spherical Ovoid Lancet-shaped Seen in pairs or chains Facultative anaerobic
Lancefield group based on serologically reactive
A
Streptococci
Carbohydrates
4
Q
Method of grouping catalase negative, coagulase negative
Based on carbohydrates on cell wall
A
Lancefield Group
5
Q
Acute pharyngitis
A
Group A
Strep pyogenes
6
Q
Neonatal meningitis
Sepsis
A
Group B
Strep agalactiae
7
Q
Gram + cocci in chains Beta hemolytic Catalase - Bacitracin-sensitive Lancefield group A
Positive PYR Test
A
Streptococcus pyogenes (Group A)
8
Q
Enzyme pyrrolidonyl arylamidase
A
PYR Test
9
Q
Strep pyogenes habitat
A
Throat
Skin
Transmitted by respiratory droplet
10
Q
Cell wall peptidoglycan
Antiphagocytic in strep pyogenes
A
M protein
Assoc with RF
11
Q
Antigenic
Oxygen labile
Subsurface hemolysis on blood agar
A
Streptolysin O
12
Q
Promotes fibrinolytic activity
Activates plasminogen
A
Streptokinase
13
Q
Enhances spread of organism through CT
A
Hyaluronidase
14
Q
Degrades DNA in exudates or necrotic tissue
A
DNAse B and NADase
15
Q
Pyrogenixity caused by direct action on the hypothalamus
Scarlet fever
A
Pyrogenic (Erythrogenic) A, B, C
16
Q
superantigen similar to TSST-1
A
(Pyogenic) Exotoxin A
17
Q
Protease rapidly destroys tissue
Necrotizing fasciitis
Necrosis factor
A
Exotoxin B
18
Q
Lipotechoic acid enzymes
A
Streptolysin Streptokinase Hyaluronidase DNAse B And NADase Pyrogenic toxins (Erythrogenic) A, B, C Exotoxin A and B
19
Q
Titers to document antecedent pharyngitis
A
ASO
20
Q
Titers to document antecedent skin infection
A
Anti-DNAse B
21
Q
Decrease efficacy of streptokinase in managing myocardial infarction
A
Anti-streptokinase
22
Q
Spectrum of Strep disease
A
Pyogenic
Toxigenic
Immunologic
23
Q
Pyogenic diseases by strep
A
Skin and soft tissue Impetigo contaigiosa Erysipelas Cellulitis Nec fasciitis Pharyngitis
24
Q
Toxigenic disease by Strep
A
Scarlet fever
Strep TSS
25
Immunologic disease by strep
Acute RF
| Glomerulonephritis
26
Perioral blistered lesions with honey-colored crust
Red rash
Impetigo contagiosa
27
Superficial infection extending into dermal lymphatics
Erysipelas
28
Deeper infection involving subcutaneous dermal tissue
| Facilitated by hyaluronidase (spreading factor)
Cellulitis
29
Rapidly progressive infection of deep subcutaneous tissues
| Exotoxin B
Necrotizing fasciitis
Flesh eating bacteria
Fournier’s
30
Cellulitus + shellfish
V vulnificus
31
Most common bacterial cause of sore throat
Inflammation, exudate, fever, leukocytosis and tender CLAD
Pyogenic complications, abscess, otitis, sinusitis, meningitis
Pharyngitis
32
Sequelae to Acute Glomerulonephritis
Pharyngitis
| Cutaneous lesions
33
Post pharyngitic
Due to erythrogenic toxin seen in lysogenized strains
Fever, strawberry tongue, centrifugal rash (sandpaper-like), Pastia’s lines, desquamation)
Scarlet fever
34
```
Susceptibility test for Strep pyogenes
Inject 0.1 cc of erythrogenic toxin
+ reddening of skin
>/= 10 mm within 24 h
Pastia lines
```
Streptococcus pyogenes
35
Strep pyogenes can cause
| Fiery red rash
Erysipelas
36
Clinically similar but milder than S aureus TSS
Due to pyogenic Exotoxin A
Recognizeable site of pyogenic inflammation
Blood culture are often positive
Streptococcal Toxic Shock-like Syndrome
37
Post pharyngitic
Only certain M protein types may be rheumatogenic
Pathogenesis not fully understood
Widely accepted theory: production of antibodies directed against a streptococcal cell wall M protein that cross reacts with myocardial tissue
Mitral valve
RHD Mitral stenosis
<1cm Fish mouth orifice
Streptococcus pyogenes
38
Post-pharyngitis or post-impetigo
Deposition of circulating streptococcal antistreptococcal immune complexes in the glomeruli
Subsequent activation of complement
HTN, peroorbital edema, hematuria
Lumpy bumpy appearance of glomerulus on light microscopy
Post streptococcal GN
39
Strep pyogenes Tx
Penicillin G
40
```
Gram + cocci in chains
Beta hemolytic
Catalase negative
Bacitracin resistant
Hydrolyze hippurate
CAMP-test-positive
```
Lancefield Group B
Streptococcus agalactiae (Group B)
41
Urinary tract infection in pregnant women
Most common cause of neonatal pneumonia, sepsis and meningitis
Habitat: vagina
Transmission: transvaginal, transplacental
```
Predisposing factor:
Intrapartum fever T >38
PROM >18h
Vaginal colonization
Complement deficiency
```
Most common cause of endometritis
Polymicrobial; foul smelling lochia
Streptococcus agalactiae Group B
42
Most common cause of neonatal pneumoniae, neonatal sepsis and meningitis
Group B agalactiae strep
43
Strep agalactiae Group B Tx
Pen G + Aminoglycoside
44
```
Gram +
Lancet shaped cocci in pairs
Diplococci or short chains
Alpha hemolytic
Catalase-negative
Bile soluble
Optochin sensitive
Prominent polysaccharide capsule
+ Quelling Reaction
```
Streptococcus pneumoniae
45
Neufield reaction
Streptococcus pneumoniae
Swelling
Quelling reaction
46
Microscopic appearance of the pneumococcal capsuke sfter their polysaccharide antigen
Strep pneumoniae
47
Habitat is upper respiratory tract
Transmission via respiratory droplet
Most cases: aspiration of oral secretions containing normal flora that includes S pneumoniae
Streptococcus pneumonaie
48
Strep pneumoniae virulence factor
Polysaccharide capsule (major virulence)
IgA protease
C-substance
49
MCC of CAO
| MCC of Otitis Media Luga
Strep pneumoniae
50
Retards phagocytosis
Polysaccharide capsule
51
For colonization
IgA protease
52
Reacts with CRP
C-substance
53
Most common cause of CAP
Sudden chills, fever, productive cough (rust colored sputum) and pleuritic chest pain
Lobar pattern
Strep pneumoniae
54
Most common cause of otitis media, sinusitis, bacterial meningitis
Skull fracture with spinal fluid leakage from nose predisposes to meningitis
Septic shock
splenectomy, predisposes to sepsis
Strep pneumoniae
55
Strep pneumoniae causes this in sicke cell anemia
Overwhelming postsplenectomy infection
56
COPD exacerbation
H influenzae
57
Associated with post-tussive vomiting
Bordetella pertussis
58
Young, otherwise healthy patients
Mycoplasm
| Atypical
59
Epidemic infection, associated with air-conditioning system
Cooling towers
Legionella
60
Alcoholics
Klebsiella
61
Following viral syndromes particularly influenza
S aureus
62
Exposure to birds
Chlamydia psittaci
| Psitaccosis
63
Bad or bird droppings, spelunking
Histoplasma
64
Exposure to rabbits, hunters
Francisella
65
Most common cause of pneumonia beyond the neonatal period
Strep pneumonia
66
Most common cause of lobar pneumonaie with rusty sputum
Strep pneumoniae
67
Pneumonia with rust colored sputum in alcoholic
Klebsiella pneumoniae
68
Strep pneumoniae Tx
Pen G
Levofloxacin or Vancomycin combined with Ceftriaxone for penicillin resistance
Atypical macrolide - Azithromycin
69
```
Gram + in chains
Alpha-hemolytic
Catalase -
Bile insoluble
Optochin-resistant
Do not grow in 6.5% NaCl
```
Strep mutans, strep sanguinis, strep mitis, strep salivarius, strep anginosus
Identification of individual species of viridans
Strep viridans
70
Streptococci requires
Conventional testing
Molecular methods
MALDI-TOF
71
Matrix assisted laser desorption/ionization
Strep viridans
72
Most common viridans streptococci responsible for liver, spleen and brain abscess
More susceptible to antibiotics than other strains of viridans
Streptococci milleri
73
Caramel odor
Strep viridans
74
Dental carries
Strep mutans
75
For subacute bacterial endocarditis SBE
| Most common cause of subacute and native valve endocarditis
S sanguis
76
Brain abscess
S intermedius
77
Strep viridans Tx
Pen G +/- Gentamycin
Vancomycin penicillin-resistance
Linezolid for vancomycin resistant
78
Bile esculin agar +
PYR Test -
Growth in 6.5 NaCl -
Streptococcus bovis
79
Bile esculin agar +
PYR test +
Growth in 6.5% NaCl
Enterococci
80
```
Associated with malignancies of GI tract
Marantic endocarditis (non-bacterial thrombotic endocarditis or marantic)
```
Complex of 7 strains and or subspecies
Four branches
Strep bovis
81
Blood CX negative endocarditis
Trophoryma pallidum
82
```
Gram +
Catalase negative
Gamma hemolytic (non-hemolytic)
Lancefield Group D
Bile and optochin-resistant
Hydrolyzes esculin in Bile Esculin Agar
PYR Negative
```
Enterococcus faecalis
83
Human colon
Urethra and female genital tract and can be colonized
May enter bloodstream during GI
Enterococcus faecalis
84
UTI due to indwelling urinary catheters and urinary tract instrumentation
Biliary tract infections
Endocarditis in patients who underwent GI tract
Enterococcus faecalis
85
Enterococcus faecalis Group D Tx
Penicillin + Gentamycin
Vancomycin for penicillin-resistance
Linezolid for vancomycin-resistance strains
