1. Cocci

2. Staphylococcus
“staphyle”
in Greek

3. Staphylococcus S.aureus: most virulent species.
S.epidermidis: opportunistic pathogen.
S.saprophyticus: rarely cause human diseases.

4. Biological characteristics
Shape and structure
Size: m in diameter
Shape: spherical
Arrangement: grape-like
Structure: capsule
non-motile
non-sporulating
Staining: G+

5. Biological characteristics
Cultivation
Requirements
media: all-purpose media
gas: facultative anaerobes
specially: tolerating 10-15% NaCl

6. Biological characteristics
Growth properties
on solid medium: small colony with various pigments
on blood agar: zone of complete hemolysis (-hemolysis)
S.aureus

7. Biological characteristics
Biochemical reactions
Catalase test “+”
Staphylococci: “+”
Streptococci: “-”
Mannitol Fermentation “+”
S. aureus: “+”;
S.epidermidis & S.saprophyticus: “-”;

8. Biological characteristics
Antigenic composition
Capsules
teichoic acid , peptidoglycan
Protein antigen: SPA
SPA
capsule
teichoic acid
peptidoglycan

9. SPA (Staphylococcal Protein A )
Characteristics
nonspecific bind to the Fc fragment of IgGs

10. SPA(staphylococcal protein A)
Function:
virulence factor
Anti-phagocytosis
damage platelet
induce hypersensitivity and inflammation
Phagocyte
Fc receptor
IgG
SPA
coagglutination test
SPA-coated S.aureus is used as Ab carriers
BACTERIUM

11. SPA (staphylococcal protein A )
S.aureus Ab

12. Biological characteristics---Classification
Based on the pigments and chemical reactions
Properties
S. aureus
S. epidermidis
S. sarprophyticus
Pigment
Golden yellow
White
Citrine
Coagulase + － －
Mannitol + － －
Thermostable nuclease + － －
α-hemolysin + － －
SPA + － －
Pathogenicity
strong
Weak -

13. Biological characteristics---Classification
Based on coagulase
Coagulase” +”: e.g., S. aureus
Coagulase” -”: e.g., S. epidermidis & S. saprophyticus
Phage typing
S. aureus: 3 phage groups, 26 phage types.
group 1: TSST-1-producing strains
group 2: exfoliative toxin-producing strains
group 3: enterotoxin-producing strains
----is of epidemiological value

14. Biological characteristics
Resistance:
Drying
Heat
high concentration of salt (10-15% NaCl)
Sensitivity:
basic dyes (crystal violet)
several antibiotics (penicillin, vancomycin)
MRSA (methicillin resistance S.aureus)

15. Pathogenicity (S.aureus)
Virulence factors
Surface structure
capsules, peptidoglycan, teichoic acid, SPA
Enzyme
Toxin

16. Pathogenicity (S.aureus)
Virulence factors
Enzymes: coagulase 血浆凝固酶
heat-stable nuclease 耐热核酸酶
hyaluronidase 透明质酸酶
lipase 脂酶
β – lactamase β-内酰胺酶
Exotoxins: Hemolysin 溶血素
Leukocidin 杀白细胞素
Staphylococcal enterotoxin 葡萄球菌肠毒素
TSST-1 毒性休克综合征毒素-1
Exfoliative toxin 表皮剥脱毒素

17. Enzyme
Coagulase:
An enzyme that converts fibrinogen into fibrin causing the coagulation of blood.
Classification:
Free coagulase 游离凝固酶
Bound coagulase 结合凝固酶

18. Coagulase Biological activity Significance
Antiphagocytosis
Inhibit the damage of bactericidal substances
Formation of limited abscess
Significance
criterion for identification of S. aureus (pathogenic)

19. Coagulase test Tube test for free coagulase
Slide test for bound coagulase

20. Hemolysins Roles: damage membrane permeability;
cytotoxic effects on phagocytes and tissue cells
Four kinds: -Lysin
-Lysin
-Lysin
-Lysin
S.Aureus in blood agar

21. Leukocidin
Biological activity
Impairment of membrane of WBC

22. Staphylococcal enterotoxin
Source: 50% S. aureus
Types: A、B、C1-3、D、E、G、H
Chemical and physical characteristics
Protein
Heat stable (100℃, 30 min)
Resistant to gut enzymes
Mechanism: act on vomiting center, superantigen
Disease: food poisoning

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

24. Toxic Shock Syndrome Toxin-1(TSST-1)
Source: phage group Ⅰ of S. aureus
Biological activity
fever
Increase the sensitivity to endotoxin
superantigen
Disease: TSS

25. Exfoliative toxin Source Biological activity protease activity
phage group Ⅱ of S. aureus
Biological activity
protease activity
Disease: SSSS
Staphylococcal scalded skin syndrome

26. Pathogenicity Disease Invasive infection/pyogenic infection
local infection: folliculitis; boil ;
carbuncle ; impetigo
organ infection: pneumonia; meningitis
Systemic infection: Septicemia; pyemia
Toxin-associated diseases

27. hair folliculitis
boil

28. Pathogenicity Toxin-associated diseases Food poisoning (enterotoxin)
TSS (Toxic shock syndrome)
SSSS (staphylococcal scalded skin syndrome)
Staphylococcal enterocolitis -dysbacteriosis

29. Staphylococcal scalded skin syndrome (SSSS)
Most often occurs in infants
and young children

30. CNS Coagulase-Negative Staphylococci Virulence factor: slime
Antibiotic-resistance
Opportunistic infection
S. epidermidis, S.saprophyticus

31. Diseases caused by coagulase-negative staphylococci
urinary tract infection
Bacterial endocarditis
Septicemia
Infections associated with indwelling devices

32. Laboratory diagnosis Specimen Direct smear and Gram stain
Isolation and identification
Primary criterions:
coagulase test,
thermostable nuclease
gold yellow pigmentation
-hemolysis
mannitol fermentation
Enterotoxin test (animal test)
Antibiotic susceptibility tests

33. Control Nosocomial infection Aseptic measures Prevention Drug
resistance
hygiene
Treatment
Autovaccino-therapy
Antibiotic susceptibility tests

35. Streptococcus

36. Shape: G+ cocci structure: capsule in chains
cell membrane
cell wall
pilus-like structure
structure: capsule
pilus-like (LTA-M protein)
carbohydrate antigen
protein antigen: M, R, T
carbohydrate antigen
and protein antigen

37. Classification Hemolytic activity Incomplete hemolysis
-hemolytic strep.
Incomplete hemolysis
Opportunistic pathogens
e.g., S.pneumoniae, S.viridans
-hemolytic strep.
Complete hemolysis()
Major human pathogens
e.g., S. pyogenes
-streptococcus
No hemolysis,
No pathogenicity
e.g., enterococci.

38. a b c

39. Classification Antigenic structure ( Lancefield 血清学分群 ) Streptococcus
C carbohydrate antigen
group-specific antigen
20 groups (A~H, K~V)
Group A- main human pathogens
Protein antigen
type-specific antigen
M, R, T protein
Group A >100 types
Cell wall
Streptococcus
capsule
protein
Polysaccharide
Peptidoglycan

40. Classification Biochemical reaction 生化反应 血清学分类 溶血反应 化脓性链球菌 咽峡炎链球菌
无乳链球菌
停乳链球菌
牛链球菌
草绿色链球菌
肺炎链球菌 A
A C F G 无相关性 B
C G D
无相关性
溶血
溶血，偶见溶血或不溶血
溶血，偶见不溶血
溶血或不溶血，偶见 溶血
溶血或不溶血
溶血

41. S. pyogenes

42. Biological characteristics
shape and size: spherical, 0.6～1.0 μm in diameter
structures: capsule (hyaluronic acid)
nonmotile
nonsporeforming
highly nutritive
-hemolysis
catalase negative

43. Pathogenicity
Virulence factors
Surface structures
Enzymes
Exotoxins

44. Pathogenicity Virulence factors Surface structures adhesin: LTA
F protein
M protein: anti-phagocytosis
cross-reactive antigen
lipoteichoic acid
F-protein
M protein
fibronectin
epithelial cells

45. Pathogenicity Virulence factors Enzymes Hyaluronidase
Streptokinase (SK)
Streptodornase (SD)
(DNase, DNaseB-Ab)

46. Pathogenicity Virulence factors Exotoxins Streptolysin (hemolysin)
Erythrogenic toxin

47. toxic to a variety of cell types
Streptolysins
streptococci group A, C, and G;
Classification:
Properties
Streptolysin O (SLO)
Streptolysin S (SLS) O2
oxygen-labile
oxygen-stable
Antigenicity
Strong (ASO test)
Weak
Chemical
Protein
Polypeptide
Activity
toxic to a variety of cell types

48. Erythrogenic toxin Pyrogenic toxin /scarlet fever toxin Protein
Antigenicity
Superantigen
Scarlet fever

49. Abscess with surrounding cellulitis
Pathogenicity
Pyogenic infection:
Local purulent infections
pharyngitis, tonsillitis,
puerperal fever 产褥热
erysipelas 丹毒,
cellulitis 蜂窝织炎
impetigo
Systemic infection: septicemia
Abscess with surrounding cellulitis

50. Erysipelas
Erysipelas on
the cheek

51. Toxin-associated diseases
scarlet fever
Hypersensitive disease
Acute glomerulonephritis
Rheumatic fever
Hypersensitivity type II & III

52. Laboratory diagnosis specimen S.aureus Isolation and cultivation
Direct smear
S.pneumoniae
PYR test
-hemolytic strep.
S. Pyogenes 阳性

53. Laboratory diagnosis Serologic diagnosis ASOT (anti-SLO test)
a neutralization test between the toxin (SLO) and its specific anti-toxin (ASO) helping to diagnose rheumatic fever and acute glomerulonephritis
positive standard：ASO titer >1:400

54. Control Treat the pharyngitis and tonsillitis in time
Antibiotics: penicillin G for the first choice

55. S. pneumoniae (Pneumococcus )

56. General properties G+, arranged in pairs, lancet-shape Capsule
Polysaccharide
Type-specific antigen
Fastidious
blood agar
-hemolysis
有氧条件下可以 形成 -hemolysis，胆汁溶菌试验，菌液中加入10% 去氧胆酸钠或2%牛磺胆酸钠，或牛、猪、兔等新鲜胆汁，置室温或37，在5－10min内出现溶解

57. General properties Autolysis Bile solubility test: “+” (-) (+)
(-) (+)
(Bile solubility test)

58. Pathogenesis Virulence factor Main disease Capsule Pneumonia
Neuraminidase
Pneumolysin
LTA, peptidoglycan
Main disease
Pneumonia
Others: middle ear infections (otitis media), sinusitis, meningitis, septicemia

59. Non-typical pneumonia

60. Laboratory diagnosis Identification of pneumococci from S.viridans
bile solubility test
optochin sensitivity test
quellung reaction (capsular swelling test)
positive
negative

61. Control Treatment: penicillin G
Prevention: polysaccharide vaccine (for children and elderly)

62. Viridans streptococci
S.mutans
S.anginosus
S.salivarius
S.mitis
S.sanguis
dental caries
subacute bacterial endocarditis
The viridans group of streptococcus are a heterogeneous collection of alpha-hemolytic and nonhemolytic streptococci. Their group name is derived from viridis(Latin for “green’) because many of these bacteria produce a green pigment on blood agar media. The taxnomic nomenclature for these species is confusing because European and American microbiologist have not reached a consensus on it. Thus different species name are often used interchangeably in the literature. At least 15 species? Have been identified in the United States, and they ar
bile solubility test （－）
optochin sensitivity test（－）

63. S.agalactiae Group B streptococcus, GBS Transmission Disease
vaginal flora
Disease
neonatal meningitis
neonatal pneumonia
septicemia

64. S. suis

65. Neisseria

66. Neisseria N. gonorrhoeae N. meningitidis N. sicca N. subflava
N. mucosa
N. lactamica

67. General properties Shape and structure G- diplococci
Coffee bean-shaped
kidney-shaped
Lipooligosaccharide (LOS)
Pili
Closely related
DNA homology 70%

68. General properties Cultivation Fastidious: chocolate agar plate
Obligate aerobes, 5～10%CO2
Autolysis (N.meningitidis)
Oxidase positive
Fermentation certain sugars
N. gonorrhoeae : Glucose
N. meningitidis : Maltose & Glucose

69. Fragile - don’t survive long outside the host
General properties
Very weak: cool, heat, drying, disinfectants
Fragile - don’t survive long outside the host

70. Pathogenesis LOS PILI N. gonorrhoeae N. meningitidis Virulence Factors
Similar, but –
Differences
in utilization
LOS
LOS
IgA1 protease
Capsule
iron-binding proteins
PILI
Outer Membrane Proteins
(Por,Opa, Rmp proteins)
IgA1 protease
iron-binding proteins
PILI
Outer Membrane Proteins

71. N. gonorrhoeae /gonococcus
PILI
Nonpiliated gonococci not virulent
Phase variation turns pilus production on/off
Antigenic variation

72. N. gonorrhoeae /gonococcus
Outer Membrane Proteins
Porin proteins (Por) = prevent phagolysosome fusion & allow intracellular survival [protein I]
Opacity proteins (Opa) = binding of organisms to epithelium [protein II]
Reduction-modifiable proteins (Rmp) = protection against bactericidal antibodies [protein III]

73. N. meningitidis/menigococcus
Capsule
13 serotype
A, B, C, Y, W-135
LOS (lipooligosaccharide)
vascular damage
skin rash
renal failure
shock
disseminated intravascular coagulation (DIC)

74. Pathogenesis X LOS PILI N. gonorrhoeae N. meningitidis
Virulence Factors
Similar, but –
Differences
in utilization
LOS
LOS
IgA1 protease
iron-binding proteins
Capsule
PILI
Outer Membrane Proteins
(Por,Opa, Rmp proteins)
IgA1 protease
iron-binding proteins
PILI
Outer Membrane Proteins X
NO capsule

75. Disease Gonorrhea Adults
Transmission: STD (sexually transmitted disease)
Clinical disease: Genitourinary tract infection
Male-Urethritis
Female-Urethritis, cervix inflammation
PID (Pelvic Inflammatory Disease)
Sterility

76. Gonorrhea
Symptomatic infections are notably PURULENT
Urethritis

77. Disease
Gonorrhea
Newborns
Ophthalmia neonatorum

78. Gonorrhea Purulent conjunctivitis Ophthalmia neonatorum
Infection in newborns
during vaginal delivery

79. Disease Source: patients and carriers Transmission: respiratory tract
nasopharynx→local infection→septicemia→meningitis
Disease: epidemic cerebrospinal meningitis

80. Laboratory diagnosis Specimens Smears Culture
Thayer-Martin VCN
Oxidase test
Maltose fermentation
Antigen Detection and Enzyme Immunoassays
Radioimmunoassay
ELISA
SPA coagglutination test
Others
DNA Probe Hybridization

81. Treatment ＆Prevention
N. gonorrhoeae
Antibiotic
1%Silver nitrate-- ophthalmia neonatorum
No effective vaccine

82. Antibiotic Resistance
Increase in penicillin resistance since 1976
PPNG (penicillinase-producing N. gonorrhoeae )
plasmid mediated
due to beta lactamase production
Tetracycline resistance recognized in 1985
TRNG (Tetracycline resistance N. gonorrhoeae )
due to chromosomal mutation
Sensitive to quinolones, cephalosporins
Penicillin used to be the drug of choice for gonococcal infections because they were essentially all sensitive to it. However, penicillin resistant strains were initially reported in Southeast Asia and were brought to the U.S. by military men returning from Viet Nam. The first ones were reported in this country in Now the recommended dose of penicillin has risen from 200,000 units in 1945 to 4.8 million units (24 times higher) today. This resistance is due to beta lactamase production that is encoded for on a plasmid (like it is in Staphs), so it can be transmitted from one strain to another.
Then in 1985, a chromosomal mutation encoding for tetracycline resistance was recognized in N. gonorrhoeae. So far, however, we can still treat these organisms with a number of our current antibiotics, including the quinolones and cephalosporins you will be hearing about.

83. Treatment ＆Prevention
N. gonorrhoeae
Antibiotic
1%Silver nitrate-- ophthalmia neonatorum
No effective vaccine

84. Treatment ＆Prevention
N. meningitidis
Treatment
penicillin: the first of choice
sulfasulfonamide
Prevention
immunization: capsule polysaccharide
group B meningitis

85. Pathogenic cocci/Pyogenic cocci
Staphylococcus aureu
Streptococcus pyogenes Streptococcus pneumoniae
G+ cocci
Neisseria meningitidis
Neisseria gonorrhoeae
G- cocci

86. Neisseriae of medical importance
Properties
N. meningitidis
N. gonorrhoeae
Gram stain
Gram-negative
Capsule
Yes No
Potal of entry
Respiratory tract
Genital tract
Virulence factors
Pili
Outer membrane protein
IgA1-protease
Iron-binding protein
LOS, Capsule
LOS
Disease
Epidemic cerebrospinal meningitis
Gonorrhea (adults)
Ophthalmia neonatorum (newborns)
Prevention
Polysaccharide vaccine
Tetracycline, erythromycin ointment or AgNO3 for ophthalmia
No vaccine for gonorrhea