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1

– they grow in the
presence of oxygen but cannot use oxygen for
respiration

Aerotolerant anaerobe

2

types of strep based on respiration (???)

Facultative anaerobe
• Aerotolerant anaerobe
• capnophilic

3

taxo A positive /
bacitracin(S)

group A strep

4

complications of group A [2]

Complications:
- rheumatic fever
- AGN

5

Infections of group A [3, PPT]

Infections:
- pharyngitis / strep throat
- pyodermal infections
- toxic shock syndrome

6

Test: detects activity
of L-pyrrolidonyl arylamidase or
pyrrolidonyl aminopeptidase

PYR

7

Meaning of PYR

(Pyrrolidonyl-anaphthylamide

8

group A strep antigenic structure
attached to the peptidoglycan of the cell wall and
extends to the cell surface
– essential for virulence

M protein

9

– Best defined virulence factor of group A strep
– Resists phagocytosis
– Adherence of bacterial cell to mucosal cells

M protein

10


Both are adhesion molecules that mediate
adherence to host epithelial cells. [group A[

Fibronectin-binding protein (protein F)
• Lipoteichoic acid

11

– Group A VF weakly
immunogenic; prevents opsonized
phagocytosis by neutrophils or macrophages;
allows bacterium to mask its antigens and
remain unrecognized by its host

Hyaluronic acid capsule

12

– hemolysis incubated anerobically;
oxygen labile; lyzes blood cells; highly
immunogenic, ASO test

SLO

13

– hemolysis incubated aerobically; oxygen
stable; lyzes WBC, nonimmunogenic

• SLS

14

Most common DNase [grp A]

DNase A,B

15

Pyodermal Infections of gp A[CISE]

Impetigo, Erysipelas, Cellulitis, scarlet fever

16


• Activates plasmin, turning itself into a tissue
degrader

Impetigo Caused by Streptococcus
pyogenes

17

- beta hemolytic (small zone)
- taxo A (-)
- CAMP test (+) / Hippurate hydrolysis(+)

Group B

18

Group B Virulence Factor
– prevents phagocytosis; ineffective
after opsonization; with sialic acid w/c inhibits
activation of the alternative pathway

• Capsule

19

Group B Virulence Factor
– most significant component of the
capsule; critical virulence determinant

• Sialic acid

20

Group B - No role in virulence [5]

• Hemolysin
• CAMP factor
• Dnase
• Hyaluronidase
• protease

21

Group B – Clinical Infections [2]

- pneumonia or meningitis with bacetermia
• Mastitis in cattle

22

Small-colony-forming-

S. anginosus (Viridans)

23

Large-colony-forming (w/ Group A) –

pyogenic
streptococci
– S. dysgalactiae subsp. equisimilis – upper
respiratory tract, vagina, skin, spectrum of
infections – like Group A

24

nonenterococcus

• Opportunistic infections

Group D Streptococcus

25

Species of Group D Streptococcus

– S. equinus
– S. bovis

26

Lab ID:
- Alpha or nonhemolytic
- PYR (-)
- psuedocatalase
- Bile esculin(+)
- 6.5% NaCl (-)

Group D Streptococcus

27


• Group D antigen
• Same infections as group D Strep

Enterococcus spp.

28

Lab ID
Varied hemolysis
- produce acid in CHO broth
- Arginine hydrolysis
- Tolerate 0.04 % tellurite (E. faecalis)
- Utilize pyruvate
- Produce acid from methyl-a-D-glucopyranoside (MGP)
- Growth around 100 ug efrotomycin disk
- motile
- PYR (+)
- Bile esculin(+)
- 6.5% NaCl(+), 45 degrees C, alkaline pH

Enterococcus spp.

29

#1 cause of bacterial pneumonia - lobar
(especially in the elderly and in those with
underlying disease) sinusitis, otitis media (most
common isolate in

s. pneumoniae

30

lab ID
- alpha hemolytic, CAP, brain-heart infusion agar,
trypticase soy agar with 5% sheep RBC;

s. pneumoniae

31

lab ID
dome shaped if young; coin with raised rim if old

s. pneumoniae

32

gram variable as culture ages
- gram (+) diplococci; lancet shape
- taxo P(+) / Optochin susceptible
- Bile solubility(+)
- Capsular Swelling(+)

s. pneumoniae

33

No Lancefield group antigens
• green – alpha hemolytic
• fastidious, some require CO2
• oropharyngeal commensals - oppportunistic

Viridans

34

5 groups under Viridans

S. mitis group
• S. mutans group
• S. salivarius group
• S. bovis
• S. anginosus

35

– Infections:
• - oropharyngeal commensals - oppportunistic

- endocarditis with transient bacteremia
- meningitis
- dental caries
- osteomyelitis

Viridans Group

36

- most common cause of SBE

Viridans Group

37

PYR (-)
• LAP (+) leucine-B-naphthylamide, is hydrolyzed to
B-napthylamine + paradimethylaminocinnamaldehyde (DMACA) = red
• alpha or non-hemolytic

Viridans Group

38

• Ferments sugars, VP, B-D-glucuronidase acitivity,
hippurate hydrolysis – for species within the
viridans group
- taxo P (-)
- Bile esculin(-)

Viridans Group

39

biochem characteristics
• Throat swab
• Growth of most interfering respiratory
micobiota will be inhibited by SXT, but S.
pyogenes and S. agalactiae will grow. – may
have variable results – do PYR

Bacitracin susceptibility

40

biochem characteristics
• B-lysin producing strain of S. aureus
• Disk impregnated with the B-lysin

CAMP test

41

biochem characteristics
– a drop of
extracted B-lysin on a colony  enhanced
hemolysis

Rapid CAMP test (spot CAMP)

42

biochem characteristics
• Hippuricase / hippurate hydrolase hydrolyzes
sodium hippurate to form sodium benzoate
and glycine
• Nihydrin
• Deep purple

Hippurate Hydrolysis

43

biochem characteristics
hydrolyzes sodium hippurate to form sodium benzoate
and glycine

Hippuricase / hippurate hydrolase

44

biochem characteristics
Detects activity of L-pyrrolidonyl arylamidase
or pyrrolidonyl aminopeptidase
• PYR impregnated disks serve as the substrate
to produce a-naphthylamine which is detected
in the presence of Ddimethylaminocinnamaldehyde (DMCA) 
red

PYR Hydrolysis

45

biochem characteristics
• Hydrolyzes peptide bonds adjacent to a free
amino group
• The substrate, leucine-B-naphthylamide, is
hydrolyzed to B-napthylamine + paradimethylaminocinnamaldehyde (DMACA) 
red

LAP

46

biochem characteristics
• Small colony forming B-hemolytic anginosus
group with groups A or C antigens vs. large
colony forming pyogenic strains with the same
antigens
• Detects acetoin production from glucose
• 5% a-naphthol + 40 % KOH; RT x 30 mins 
red or pink color

VP

47

biochem characteristics
• Enzyme in large colony forming B-hemolytic
Groups C and G Strep
• (-) in small colony forming B-hemolytic
anginosus group

B-D-Glucoronidase

48

biochem characteristics
• cfb gene – encodes CAMP-factor protein
• ptsI (phosphotransferase) – Group A, C and G
can be distinguished

Nucleic Acid Probes

49

biochem characteristics
• Autocatalytic enzyme amidase
• Organism’s cell wall lyses during cell division
• Suspension in solution of Na deoxycholate
lyses  solution becomes clear

Bile Solubility

50

biochem characteristics
• Incubate overnight at 35 degrees C in a CO2
incubator
• Zone of inhibition > 14 mm with a 6 mm disk
or >16 mm with a 10 mm disk
• Do bile solubility if zone is smaller

Optochin Susceptibility

51

A-naphthylamine detected in the lresence of

Dimethylcinnamaldehyde

52

DMCA meaning

Dimethylcinnamaldehyde

53

Uncommon human pathogens

Group C and G strep

54

VF of e faecalis

Extracellularw serine protease
Gelatinase

55

VF of e faecalis which contribute to colonization and adherence to heart valves

Extracellularw serine protease
Gelatinase

56

Enterococcus with cytolysin

E faecalis

57

SBE meaning

Subacute bacterial endocarditis

58

Chemical reaction of s pneumoniae

CRP + C substance = ppt

59

Treatment for strep pneumoniae

Penicillin

60

Treatment for strep pneumoniae if penicillin resistant

Erythromycin and chloramphenicol

61

Strep with antigen c similar to c carbohydrate of lancefield grouping

S pneumoniae

62

How manu serotypes are there for strep pneumoniae based on capsular antigens

82

63

Sterile pleural effusion

Empyema

64

Opportunistic, oropharyngeal commensals

Viridans

65

CM for strep pneumoniae

CAP
BHI
TSA with 5% sheep RBC

66

Colonial characteristic of spneumon if young

Dome shaped

67

Colonial characteristic of spneumon if old

Coin with raised rim

68

Lancet shape strep

Pneumoniar

69

Group of strep
Fastidious
Some require CO2

Viridans

70

DMACA

Dimethylaminocinnamaldehyde

71

5 classif schemes [HPCBS]

Hemolytic pattern on BAP
Physiologic characteristics
Serologic grouping [lancefield]
Capsular polysaccharide
Biochemical characteristics

72

Meaning of LAP

Leucine Aminopeptidase

73

Motility of strep

Nonmotile

74

Motility of enterococcus

Motile

75

C carbohydrate present in all except

Viridans group

76

Lancefield classif based on

Cell wall structure

77

AGN meaning

Acute glomerular nephritis

78

Large colony isolates

S. dysgalactiae subspecies equisimilis

79

VP detects ---

Acetoin

80

biochem characteristics
• For non hemolytic, catalase (-), g(+) cocci
• 40 % bile; ability to hydrolyze esculin (for
Group D and Enterococcus)
• Enterococcus and Aerococcus grow in 6.5%
NaCl broth

Bile Esculin and Salt Tolerance

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