1. Pyogenic Coccus

4. The Staphylococci

5. Morphology & Identification
Gram positive
Facultative anaerobes
Grape like-clusters
Catalase positive
Major components of normal flora
skin
nose

6. Gram Positive cocci - staphylococci
Pus

7. Catalase test（过氧化氢酶）
(-) (+)

8. Pathogenesis & Immunity of Staphylococcus aureus

9. Antigenic Structure

10. Protein A inhibits phagocytosis
PHAGOCYTE
Fc receptor
immunoglobulin
Protein A
BACTERIUM

11. Toxins & Enzymes Catalase Coagulase Hyaluronidase and Lipase
Hemolysin or sphingomyelinase C
Leukocidin
Exfoliative Toxin
Toxic Shock Syndrome Toxin (superantigen)
Enterotoxins

12. Pathogenesis

13. Pathogenesis of staphylococcal infections
Stye:麦粒肿
Carbuncle:痈
Impetigo：脓疱疮

14. Infections associated with indwelling devices

15. Superantigens and the non-specific stimulation of T cells

16. Clinical Findings- Suppurative
A. (Skin)
Furuncle; Protein A, Leukocidin, Hemolysin
Stye; lipase
Impetigo; contagious
Epidermal necrolysis
Exfoliative Dermatitis (6,7,8); Exfoliative toxin
Mastitis
Abscess (deep tissue); granulation; coagulase, hyaluronidase (burn, wound)
B. Systemic : Bactermia (from abscess, wound, burn) , Osteomyelitis (tibia) ,Pneumonia

18. Clinical Findings- Food poisoning
not a human infection
food contaminated from humans
growth
enterotoxin
onset and recovery both occur within few hours
Vomiting/ nausea/ diarrhea/ abdominal /pain

19. Toxic shock syndrome fever scarlatiniform rash desquamation vomiting
diarrhea
myalgias

20. S. aureus
babies
scalded skin syndrome
exfoliatin

21. Pseudomembranous Colitis

22. Laboratory A. Direct examination; Gram Stain B. Primary media; BAP
C. Differential Tests.
Mannitol Salts
Coagulase
DNase
D. Phage typing
E. Antibiotic Sensitivity (plasmid, B lactamase)
penicillin /methicillin/vancomycin

24. S. aureus on BAP

25. Mannitol Salt Agar

26. DNase test
0.1% Toluidine blue O
(+): Pink
1N HCl (+) :

27. S. aureus on potassium tellurite agar

28. Lysostaphin test
Staphylococcus Micrococcus

29. API STAPH Kit

30. Staphylococcus epidermidis
major component skin flora
opportunistic infections
less common than S.aureus
nosocomial infections
heart valves
Identification
Non-hemolytic (sheep blood agar)
Does not ferment mannitol
Non-pigmented
Coagulase-negative

31. Staphylococcus saprophyticus
urinary tract infections
coagulase-negative
not differentiated from S. epidermidis

32. The Streptococcus

34. Streptococcus

36. Morphology & Identification
facultative anaerobe
Gram-positive
Chains or pairs
Catalase negative
(staphylococci are catalase positive)

37. Cell surface structure of S pyogenes and extracellular substances

38. S. pyogenes
lipoteichoic acid
F-protein
fibronectin
epithelial cells

39. M protein major target strain variation re-infection natural immunity
antigenicity
re-infection
occurs with different strain

40. M protein IMMUNE Complement IgG M protein NON-IMMUNE peptidoglycan
fibrinogen r

41. Capsules
Anti-phagocytic
mucoid strains

42. Streptococci
Lancefield groups
one or more species per group
surface antigens

43. groupable streptococci
A, B and D
most important
C, G, F
rare

44. Non-groupable S. pneumoniae viridans streptococci pneumonia
e.g. S. mutans
dental caries

45. Toxins & Enzymes

46. Hemolysis
alpha
beta
gamma

47. Classofication of Streptococci of Particular Medical Interest

48. Pathogenesis of S pyogenes infections.

49. Group A streptococcal infections affect all ages peak incidence at 5-15 years of age

50. S. pyogenes -suppurative
non-invasive
pharyngitis
skin infection, impetigo
invasive bacteremia
toxic shock-like syndrome
"flesh eating" bacteria
pyrogenic toxin

51. Pyrogenic toxin
superantigen
T cell mitogen
activates immune system

52. Scarlet fever
rash
erythrogenic toxin

53. non-suppurative rheumatic fever inflammatory disease life threatening
chronic sequalae
fever
heart
joints
rheumatic NOT rheumatoid arthritis

54. Rheumatic fever -etiology
M protein
cross-reacts heart myosin
autoimmunity
cell wall antigens
poorly digested in vivo
persist indefinitely

55. Rheumatic fever

56. Acute glomerulonephritis
immune complex disease of kidney

57. Group B streptococcus neonatal meningitis septicemia transmission
vaginal flora

58. Group B streptococcus - identification
 hemolysis
hippurate hydrolysis
CAMP reaction
increases  hemolysis of S. aureus

59. Group D streptococcus Growth on bile esculin agar black precipitate
6.5% saline
grow
enterococci
no growth
non-enterococci

60. Enterococci distantly related to other streptococci genus Enterococcus
gut flora
urinary tract infection
fecal contamination
opportunistic infections
particularly endocarditis
most common E. (S.) faecalis

61. Enterococci resistant to many antibiotics including vancomycin
terminal D-ala replaced by D-lactate

62. Viridans streptococci
diverse species
oral
dental caries
 hemolytic and negative for other tests
non-groupable.
includes S. mutans
endocarditis
tooth extraction

63. Diagnostic Laboratory Test

64. Post-infectious diagnosis (serology)
antibodies to streptolysin O
important if delayed clinical sequelae occur

65. Serotyping M T R

67. S. pneumoniae - diplococci

68. S. pneumoniae Virulence factors
a. capsule: It is antiphagocytic, inhibiting entrapment and phagocytosis where type-specific opsonic antibody is absent. Non-capsulate mutants are avirulent in experimental animals.
b. pneumolysin: It suppresses phagocytic oxidative burst. It is a membrane-damaging toxin. Thus it can destroys red blood cells and possibly ciliated epithelial cells.
c. Surface protein adhesinand secretory IgA protease: The biologic effects are to help S.pneumoniae for the colonization and migration.
d.Teichoic acid and the Peptidoglycan fragment, phosphorylchorine : They can mediate the mobilization of inflammatory cells to the focus of infection and cause the tissue destruction/complement activation

69. Capsule prominent virulent strains anti-phagocytic
carbohydrate antigens
vary among strains
immunity
serotype specific
vaccine contains multiple serotypes
only for susceptible population

70. clinic finding leading cause pneumonia particularly young and old
after damage to upper respiratory tract
*e.g. following viral infection
bacteremia
meningitis
middle ear infections (otitis media)

71. (-) (+)
(Bile solubility test)

72. Autolysis - identification
autolysin
Bile
teichoic acid
-choline
peptidoglycan
cell
membrane
lipoteichoic acid

73. Identification
Not optochin sensitive
optochin sensitive

74. Quellung reaction using antisera capsule "fixed"
visible microscopically

75. Streptex antiserum

76. Latex agglutination - streptococci

78. Prevention and Treatment
Immunity ; 14 capsule types mixed vaccine
Most strains susceptible to penicillin , but resistance is common

79. NEISSERIA
Neisseria gonorrhoeae

80. Neisseria Gram negative diplococci (pairs of cocci) oxidase positive
culture
Thayer Martin.
selective
chocolate agar
heated blood (brown)

81. X LPS PILI Capsule N. meningitidis N. gonorrhoeae Virulence Factors
Similar, but –
Differences
in utilization
LPS
LPS
IgA protease
Capsule
PILI
Opacity (OPA) proteins
Outer Membrane Proteins
Hemolysin
IgA protease
PILI
Opacity (OPA) proteins
Outer Membrane Proteins X
NO capsule
NO hemolysin

82. N. gonorrhoeae the "gonococcus" After 2-14 days Found only in man
Gonorrhea: second most common venereal disease

83. Neisseria gonorrhoeae
Gram stain of pure culture Urethral exudate
Using the Gram stain in patient specimens,
the organisms are most often observed
in polymorphonuclear leukocytes

84. Neisseria gonorrhoeae

85. Neisseria gonorrhoeae
Pili = key in anchorage of organisms
to mucosal epithelium.
Nonpiliated gonococci are avirulent
OUTER MEMBRANE PROTEINS
Porin proteins (Por) = prevent phagolysosome fusion & allow intracellular survival [ also called protein I]
Opacity proteins (Opa) = binding of organisms to epithelium
[also called protein II]
Reduction-modifiable proteins (Rmp) = protection against bactericidal antibodies [ also called protein III]

86. Neisseria gonorrhoeae
Symptomatic infections are notably PURULENT
Urethritis

87. Neisseria gonorrhoeae
Symptomatic infections are notably PURULENT
Bartholin’s Duct

88. Neisseria gonorrhoeae
Purulent conjunctivitis
Ophthalmia neonatorum
Infection in newborns
during vaginal delivery

90. Neisseria gonorrhoeae
Disseminated gonococcal infection (DGI).
Fever, polyarthritis
(or monoarticular septic arthritis),
and/or dermatitis
(pustules on a hemorrhagic base).

91. Smear
polymorphonuclear cell
Gram negative cocci
many in cells
Culture

92. Antibiotic therapy  lactamase-resistant cephalosporin
e.g. ceftriaxone
resistant strains
common
produce  lactamases
destroy penicillin

93. N. meningitidis (the "meningococcus")

94. N. meningitidis resides in man only usually sporadic cases
mostly young children
outbreaks
adults
crowded conditions
e.g. army barracks

95. Neisseria meningitidis
upper respiratory tract infection
adhesion pili
bloodstream
brain

96. Meningococcal meninigitis
1-4 days
Second most common meningitis
pneumococcus, most common
Fatal if untreated
Responds well to antibiotic therapy
penicillin

97. Laboratory Diagnosis spinal fluid Gram negative diplococci
within polymorphonuclear cells
meningococcal antigens
Culture
Thayer Martin agar

98. Prevention - Capsule capsule inhibit phagocytosis
anti-capsular antibodies
stop infection
antigenic variation
serogroups
vaccine
multiple serogroups