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Page 1: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 2: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 3: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 4: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 5: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing 7.5% NaCl, mannitol and phenol red).

Page 6: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 7: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 8: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 9: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

staphylococcal food poisoning

toxic shock syndrome

staphylococcal scalded skin syndrome

exfoliatin enterotoxin

TSST-1

Page 10: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 11: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

StreptococciStreptococci

Page 12: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

oral cavity

intestinal tract

female genital tract

anaerobes

Page 13: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Rebecca Craighill Lancefield (1895 –1981)

She is most famous for her serological classification of beta-hemolytic streptococcal bacteria, which is based on the carbohydrate composition of bacterial antigens found on their cell walls.

Lancefield classification: A serologic classification of hemolytic streptococci, dividing them into groups A to V, 20 groups.

Most human pathogens are from Group A, eg. Streptococcus pyogenes.

Page 14: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

•pyogenic inflammation•scarlet fever•streptococcal toxic shock syndrome•rheumatic heart disease •glomerulonephritis

Page 15: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

M proteinM protein

rrr

peptidoglycanpeptidoglycan

Complement Complement fibrinogenfibrinogen

M protein

It is a component of group A streptococci pili that can inhibits phagocytosis. M protein binds

fibrinogen in plasma which blocks complement to bind to the underlying peptidoglycan layer.

Page 16: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

M protein may have cross antigenecity with

some of human tissue such as endocardium

and glomerular basement membrane.

the bigger problem is…

Page 17: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

type III hypersensitivity (most)

M protein-Ab immune complex

deposition on glomerular basement membrane

activation of complement

tissue destruction

type II hypersensitivity

common Ag

cross reacts with glomerular basement

membrane

tissue destruction

Page 18: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Acute glomerulonephritis happens !

a disease of kidney caused by the immune

complex during the infection of Group A

streptococci (S. pyogenes). In this disease type

III hypersensitivity and type II hypersensitivity

are involved.

Then…

Page 19: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Rheumatic fever happens !

An autoimmune disease caused by the

infection of Group A streptococci (S.pyogenes).

It affects primarily the heart (rheumatic heart

disease) and joints (rheumatic arthritis).

Then…

Page 20: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

1. Hemolysins: cytolytic.

2. Hyaluronidase (spreading factor): digest

hyaluronic acid in connective tissue.

3. Streptokinases: lyse fibrin.

4. Streptodornases: degrade DNA.

5. Pyrogenic exotoxins (Erythrogenic Toxins):

encoded by a bacteriophage gene, has

protease activity to cause soft tissue necrosis

or toxic shock syndrome.

What’s more, …

Page 21: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

•pyogenic inflammation•scarlet fever•streptococcal toxic shock syndrome•rheumatic heart disease •glomerulonephritis

Page 22: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

•Local infection: Group A streptococci (S. pyogenes)

causes many inflammatory pyogenic inflammation such as

impetigo ( 脓泡疹 ), pharyngitis ( 咽喉炎 ), tonsillitis ( 扁桃体

炎 ), cellulitis ( 蜂窝织炎 ), and erysipelas (an infection of the

skin in legs characterized by massive edema, 丹 毒 ),

tympanitis ( 中耳炎 ), sinusitis ( 鼻窦炎 ).

•Systemic infection: Group A streptococci (S. pyogenes)

causes pneumonia, osteomyelitis ( 骨 髓 炎 ), arthritis and

meningitis.

Pyogenic infections

Page 23: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

treat early

penicillin G

Page 24: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Streptococcus Streptococcus

pneumoniaepneumoniae

(the pneumococcus)(the pneumococcus)

Page 25: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 26: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

colonize respiratory tract

The diseases it causes:

pneumonia

tympanitis (otitis media)

meningitis

Page 27: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

- +

Streptococcus pneumoniae

produces autolytic enzymes called

as autolysin.

Bile salts such as sodium

deoxycholate can activate

autolysin.

Bile Solubility Test: Add bile-salt

solution into an established broth

culture. Streptococcus

pneumoniae positive culture is

clear with no turbidity.

Page 28: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Optochin Test: is an assay which is used to identify strains

of S. pneumoniae. Optochin disks are placed on inoculated

blood agar plates. Because S. pneumoniae is not resistant

to optochin, a zone of inhibition will develop around the

disk where the bacteria have been lysed.

- +

Page 29: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

MMost strains of ost strains of S. pneumoniaeS. pneumoniae are sensitive are sensitive

to penicillinto penicillin but but the resistance is frequent. the resistance is frequent.

A vaccine with a mixture of A vaccine with a mixture of capsule from 14 capsule from 14

serotypes serotypes is available.is available.

Page 30: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

NeisseriaNeisseria

Page 31: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Chocolate blood agar, an enriched, non-selective

medium. Contains red blood cells that have been

lysed by heating very slowly to 56 °C. Lysed red blood

cells provide growth factors, and is the cause for the

brown color.

Page 32: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Neisseria meningitidis (the meningococcus)

Page 33: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Colonize upper respiratory tract in human. It can invade bloodstream and finally the brain.

The diseases:meningitisepidemic cerebrospinal meningitis

Page 34: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 35: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 36: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Virulence factors Pilus:

adhesion

Capsuleinhibits phagocytosis

Endotoxinthe main pathogenic substance

Page 37: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Neisseria gonorrhoeae (the gonococcus)

Page 38: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

pyogenic effusionfrom a patient (acute urethritis)

Page 39: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 40: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

pyogenic effusion from a newborn’s right eye

Page 41: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Diseases

Acute urethritis (male) Pelvic inflammation (female) Ophthalmia neonatorum

(infected from the vagina of gonorrhea parturient)

Page 42: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Virulence factors Pilus

The gonococci with no pili are avirulent

IgA1 proteasedestroy secretary IgA (S-IgA)

EndotoxinOuter membrane protein (OMP)

Porin proteins (PI) suppress phagosome-lysosome fusionOpacity proteins (Opa, PII) help the bacterium bind to the epitheliumReduction-modifiable proteins (Rmp, PIII) inhibit activity of the specific antibody

Page 43: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Sample collection: the two pathogens are very fragile. They are extremely sensitive to dryness, heat and coldness.

A smear from spinal fluid for cerebrospinal meningitis or pyogenic effusion for gonorrhea may show the presence of Gram-negative diplococci present in polymorphonuclear cells.

Page 44: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing
Page 45: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Penicillin therapy: Still used for cerebrospinal meningitis and gonorrhea. Resistant strains of gonococcus producing beta-lactamase are very common.

Page 46: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

For prevention of ophthalmia neonatorum, 0.1 % silver nitrate solution (AgNO3) is dropped into the eyes after the baby is born.

Page 47: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

There are two vaccines of the meningococcus, which are mixture of groups A and C capsule or a mixture of groups A, C, Y and W135 capsule. No gonorrhea vaccine is available.

Page 48: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Streptococcus pyogenes on mannitol salt agar plates (containing

Summary

1. Diseases and molecular mechanisms of Streptococci2. Identification of the pneumococcus (diagnosis)

3. Diseases and diagnosis of two species of Neisseria