[VMCB 122] Staphylococcus and Streptococcus

Staphyle

a bunch of grapes

Hydrogen Peroxide

What does catalase break down into water and oxygen

True

Staphylococci is catalase positive

False

Streptococci is catalase positive

C. S. epidermis

The following is coagulase positive except:

A. S. aureus

B. S. intermedius

C. S. epidermis

D. S. hyicus

A. Coagulase

Converts fibrinogen to fibrin, clotting plasma, and help bacteria evade phagocytosis.

A. Coagulase

B. Catalase

C. Coagulants

D. Peroxidase

S. aureus

What does coagulase test differentiate from less pathogenic staphyloccal species?

Slide test

Type of coagulase test that detects bound coagulase

Tube Test

Type of coagulase test that detects free coagulase

B. Clumping factor (bound coagulase)

Cause organism to clump in the presence of

plasma

A. Presence of teichoic acid linked to

peptidoglycan

B. Clumping factor (bound coagulase)

C. Presence of capsule to some or pseudo-

capsule

D. Carotenoid pigments in cell membrane (staphyloxanthin)

Protein A

Binds to Fc moiety of IgG , exerting anti-opsonin (and therefore strongly antiphagocytic effect)

A. Clumping factor (bound coagulase)

B. Presence of capsule to some or pseudo capsule

C. Presence of teichoic acid linked to peptidoglycan

D. Protein A

C. staphyloxanthin

Acts as an antioxidant, (neutralizing harmful ROS produced by immune cells during infection)

A. Protein A

B. Clumping factor (bound coagulase)

C. staphyloxanthin

D. Presence of capsule to some or pseudo capsule

C. presence of teichoic acid linked to peptidoglycan

Inhibits anti-inflammatory response

A. anti histamine

B. Protein A

C. teichoic acid linked to peptidoglycan

D. Clumping factor

Presence of capsule to some or pseudo capsule

Adheres to host cells

A. Flagella

B. Pili

C. Presence of capsule or pseudo capsule

D. Filaments

Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMMs)

Important adhesins, Surface-anchored molecules that bind host molecules like collagen, elastin, and fibrinogen etc

Clumping Factor A (ClfA)

a surface protein, facilitates adhesion to fibrinogen in blood or plasma resulting to clumping of the bacteria

False

T OR F: Fibrin clots reveal the bacteria from

phagocytic cells

Protein A

A surface protein well characterized from strains of S. aureus and S. pseudintermedius, can bind the Fc portion of immunoglobulins, especially certain IgG subtypes, from certain host species.

Peptidoglycan

Major structural component of the

cell wall

Teichoic Acid

Mediates the attachment of the bacteria to mucosal surface

Coagulase

Clots plasma to wall off bacteria

Hyaluronidase

Breaks down hyaluronic acid, enabling the bacteria to

spread between cells

ℬ-lactamases

Breaks down penicillin and allows the bacteria to survive treatment with Beta-lactam antimicrobial drugs.

Staphylokinase

Dissolves fibrin threads in blood clots, allowing S. aureus to free itself from clots

Leukocidins

Kill leukocytes

Toxic shock syndrome toxin (TSST-1)

Systemic inflammation

Exfoliative toxin

Epidermal (skin) damage → greasy pig disease

Hemolytic toxins

- When cultured on blood agar, it will be visible

- Causes RBC's to burst open

Staphylococci

frequently give rise to colonies that exhibit hemolytic zones on BAP

A-hemolysis

incomplete/partial hemolysis (green/brown)

B-hemolysis

complete hemolysis

Gamma hemolysis

No hemolysis

Enterotoxins

Responsible for food poisoning in man

Exfoliative toxin

Causes necrosis of skin by _______ and intraepidermal separation

food poisoning

Responsible for ____________ in man

Enterotoxin B

Type of enteroctoxins that causes staphylococcal pseudomembranous enterocolitis

C and D

Type of enterotoxin found in contaminated milk

Enterotoxin A

Enterotoxin most commonly associated with disease

B. Systemic disease

Toxic shock, bacteremia, endocarditis, pneumonia, etc.

A. Non-invasive disease

B. Systemic disease

C. Cutaneous disease

D. Respiratory disease

C. Cutaneous disease

Various skin conditions including scalded skin, impetigo, folliculitis

A. Non-invasive disease

B. Systemic disease

C. Cutaneous disease

D. Respiratory disease

A. Non-invasive disease

Food poisoning from the ingestion of enterotoxin-contaminated food

A. Non-invasive disease

B. Systemic disease

C. Cutaneous disease

D. Respiratory disease

D. Chicken pox

The following are staphylococcus infection in humans except:

A. Exfoliative disease

B. Food poisoning

C. Cutaneous infections

D. Chicken pox

Staphylococcus aureus

Causes contagious mastitis in

cows

Staphylococcus hyicus

Greasy pig disease is caused by

Staphylococcus aureus

Bumblefoot is caused by

Staph intermedius

Pyoderma and Otitis externa (and other supperative conditions) is caused by

Pyoderma

Usually triggered by an

overcolonization of normal

resident or transient flora

True

T or F: Staph aureus usually forms gray to deep golden yellow colonies

Oxacillin (Methicillin)

Cephalosporins (Cefazolin, Cephalotin)

Antibiotics: First choices

• Lincosamides (Clindamycin)

• Glycopeptides (Vancomycin, Teicoplanin)

Antibiotics: Second choices

Methicillin-resistant Staphylococcus aureus

MRSA meaning:

MRSA (Methicillin-resistant staphylococcus aureus)

- In this type of mutation on S. aureus, it renders it resistant to all β-lactam antibiotics (methicillin, penicillin, cephalosporins, carbapenems)

- Carries mecA gene

Streptos

Greek word for chains

Staphylococcus

Bacteria found in skin, URT, LUT, and as transients in digestive tract

Streptococcus

- Bacteria found in mucous membrane and URT

- Commensals and saprophytes on decaying matter

Enterococcus

Bacteria found in the intestinal tract

Lancefield Grouping Scheme

Categorizing beta-hemolytic streptococci based on the antigens found in their cell walls

20 groups, I and J

The lancefield grouping scheme is divided into _______ (A thru V, but with no ___ and ___)

Rebecca Lancefield

Who introduced lancefield grouping

M (Mucoid) Protein

Cell wall antigen which has anti-phagocytic property

Probable adhesin of S.equi and of Group B streptococci in adults

Protein F

Promotes adhesion and internalization by epithelial cells

Streptokinase (Fibrinolysin)

Lyses fibrin barrier around infected site, facilitating spread of infection

DNAses A, B, C and D (Streptodornase)

- Degrade DNA

- Liquefy viscous inflammatory exudate

Erythrogenic Toxins (Pyrogenic Toxin)

Responsible for the rash in scarlet fever, Release large amounts of cytokines, pyrogenicity and lethal shock

Streptococcus pyogenes

- Major human-specific bacterial pathogen

- Causes a wide array of manifestations ranging from mild localized infections to life-threatening invasive infections

- postinfectious sequela acute rheumatic fever

- post-streptococcal glomerulonephritis

- invasive infections like necrotizing fasciitis

Streptococcal mastitis

Streptococcus agalactiae, S. dysgalactiae and S. uberis are the principal pathogens involved in __________________

S. agalactiae

contagious mastitis

S. dysgalactiae

environmental mastitis

Milking hygiene, Environmental mgt, Segregation of infected cows, antibiotics, vaccination

Proper management and prevention of streptococcal mastitis (5)

S. equi subsp. equi (Strangles)

Acute, contagious upper respiratory tract disease of predominantly young horses characterized by rhinopharyngitis and lymphadenitis of the submandibular and retropharyngeal lymph nodes.

S. equi subsp. equi (Strangles)

A horse is presented with these symptoms, what could be the probable diagnosis?

•Snotty nose, a thick yellow-white

discharge

•Enlarged lymph nodes under jaw

•Fever

•Lethargy and/or depression

•Loss of appetite

•Difficulty swallowing

Penicillin

Treatment of S. equi subsp. equi (Strangles)?

Streptococcus suis

This bacteria is ssociated with meningitis, arthritis, septicemia and bronchopneumonia in pigs of all ages

Enterococcus

______________ species cause opportunistic infections:

• wound infections in all species

• mastitis in cattle

• urinary tract and ear infections in dogs

E. faecalis

• most frequently isolated from domestic animals and poultry

• formerly classified as part of the group D Streptococcus

Enterococcus faecium

also found in the intestinal tract of many species.

S. aureus, S. agalactiae, S. dysgalactiae

What 3 species causes mastitis (3)

Christie, Atkins, and Munch-Petersen

CAMP is named after?

CAMP phenomenon

hemolytic synergism between

staphylococcal beta toxin and a S.

agalactiae toxin

Group B Streptococcus — particularly Streptococcus agalactiae

CAMP test is a confirmatory test used to identify _____________

Edwards medium

This is highly selective for the streptococci and also indicates aesculin hydrolysis and the type of hemolysis.

Oral penicillin V or amoxicillin; Intravenous penicillin with protein inhibiting antibiotics

Treatment for streptococcal pharyngitis is _________ and

For severe systemic infection ________________

Streptococcus pyogenese

the species ____________ have developed resistance over tetracyclines and sulfonamides, newer macrolides