Lecture 12: Streptococcus Respiratory Infections and Mastitis Flashcards by Jen McGann

Are streptoccci gram positive or negative

Positive

How well did you know this?

Not at all

Perfectly

Streptococci are arranged in ___ or __

Pairs or chains

How well did you know this?

Not at all

Perfectly

Are streptocci commensal organisms

Yes, found in upper respiratory tract, GI tract, lower urogenital track but become opportunistic pathogens

How well did you know this?

Not at all

Perfectly

Streptococci are ___ anaerobes

Facultative

How well did you know this?

Not at all

Perfectly

Are streptococci catalase positive or negative

Negative

How well did you know this?

Not at all

Perfectly

What is the appearance of colonies for streptococci

Clear, gray, white or yellow with smooth and mucoid appearance

How well did you know this?

Not at all

Perfectly

T or F: streptococci are fastidious

True

How well did you know this?

Not at all

Perfectly

T or F: streptococci are capnophiles

True

How well did you know this?

Not at all

Perfectly

T or F: streptococci have hemolytic patterns

True

How well did you know this?

Not at all

Perfectly

How are streptococci classified

Lance field classification based on group specific cell wall carbohydrate

How well did you know this?

Not at all

Perfectly

What test can be performed to determine lancefield group

Latex agglutination test

How well did you know this?

Not at all

Perfectly

what lancefield group is this streptococci

B- clumping

How well did you know this?

Not at all

Perfectly

What is the function of the polysaccharide capsule

Inhibits phagocytosis
Produced smooth/mucoid appearance of capsules

How well did you know this?

Not at all

Perfectly

What are the functions of peptidoglycan and LTA

Potent pyrogens
Induce cytokine secretion
LTA is an adhesin

How well did you know this?

Not at all

Perfectly

What is the function of fimbrial M protein

Adhesin
Inhibits complement
Antiphagocytic
Associated with post-streptococcal immune response

How well did you know this?

Not at all

Perfectly

What are the function of hemolysins and what ones are found in streptococci

Destroy RBC’s, responsible for B-hemolysis

Streptolysins O and S

How well did you know this?

Not at all

Perfectly

What are the function of DNases

Degrades DNA, liquifies pus to facilitate spread, evade immune responses

How well did you know this?

Not at all

Perfectly

What are the function of hyaluronidases

Break down hyaluronic acid in ECM and facilities spread

How well did you know this?

Not at all

Perfectly

What is the function of streptokinase/ Fibrinolysis

Dissolves blood clots and facilitates spread

How well did you know this?

Not at all

Perfectly

What do streptococcal pyrogenic exotoxins (Spe) do and what are the relevant types

SpeA and SpeC are superantigens that result in non-specific activation of T cells—> cytokine storm—> toxemia

How well did you know this?

Not at all

Perfectly

Severe mastitis is often due to gram ___bacteria

Negative—> endotoxemia

How well did you know this?

Not at all

Perfectly

What streptococcal species is responsible for contagious bovine mastitis

S. Agalactiae

How well did you know this?

Not at all

Perfectly

S. Agalactiae causes what type of hemolysis

Beta

How well did you know this?

Not at all

Perfectly

Is S. Agalactiae CAMP negative or positive

Positive

How well did you know this?

Not at all

Perfectly

Which organism is an intermediate pathogen in bovine mastitis

S. Dysgalactiae

What hemolytic pattern does S. Dysgalactiae cause

Alpha

Is S. Dysgalactiae CAMP positive or negative

Negative

What streptococcal organism causes environmental mastitis

S. Uberis

What hemolytic pattern does S. Uberis have

Alpha

Is S. Uberis CAMP negative or positive

Negative

How does the CAMP test work for S. Agalactiae

CAMP factor produced by S. Agalactiae which enhances the hemolysin activity of staphylococcus aureus and produces an arrowhead shaped hemolysis

What are the 3 mediums on the tri-plate and what do they test for

1. MacConkey-gram negative 2. Factor- gram positive 3. MTKT- streptococcus

What is strangles

Equine distemper in horses causes by S. Equi resulting in infection of upper respiratory tract

What are some signs of strangles

Purulent oculonasal discharge, painful abscesses in regional LN

Strangles causes abscesses in regional LN which can result in what 3 signs

1. Difficulty swallowing 2. Extended head and neck 3. Difficulty breathing

Abscess rupture in strangles leads to ___

1. Purulent exudate 2. Guttural pouch emphysema 3. Chondroids

How is streptococcus equi transmitted

Nasal secretions or purulent discharge from abscess via direct or indirect

What is the incubation period for S. Equi

3 days to 2 weeks but horses can remain infectious for several weeks and become chronic carriers

What is the pathogensis of S. Equi

1. Entry of pathogen 2. Attach to crypts of lingual and palatile tonsils (adhesins and capsules) 2. mandibular an suprapharyngeal LN 3. Failure of neutrophils to kill (SeM protein, hyaluronic acid) 4. Streptolysin and streptokinases- abscess 5. Spread to other organs 6. Bastard strangles

What is purpura hemorrhagica

Complication of S. Equi following infection or vaccination. Immune response against bacterial M protein

What type of hypersensitivity reaction is Purpura hemorrhagica

Type III—> immune complex deposition in vessel walls

What are some clinical signs of purpura hemorrhagic

Edema, vasculitis, mucosal hemorrhages

Vasculitis that occurs in purpura hemorrhagica is mainly due to release of damaging enzymes by what cell type

Neutrophils—> can’t phagocytize so release lyric enzymes—> tissue damage

How do you diagnose S. Equi

1. Culture- gram positive streptococci and B-hemolysis 2. PCR- detection of species specific M protein (SeM)

What do you expect to see on culture of S. Equi

Gram positive streptococci and Beta-hemolysis

What test can you do to differentiate between S.equi spp and other streptococcal species

PCR detection of SeM protein

What is treatment for S. Equi

1. Supportive care 2. Anti-inflammatory medications 3. Antibiotics contraindicated but if needed use penicillin

Why are antibiotics contraindicated in tx of S. Equi

Hard to penetrate abscess and slow resolution of disease and can risk spread to other LN

How do you manage S. Equi

1. Quarantine 2. Disinfect 3. Vaccines

What organism can cause hemorrhagic pneumonia

S. Equi zooepidemicus

The initial signs of S. Equi zooepidemicus are similar to __

Kennel cough

The rapid onset of deterioration from S. Equi zooepidemicus is due to what

Cytokine storm—> pro inflammatory cytokines released

S. Equi zooepidemicus is associated with what type of settings

Kennel

How does S. Equi zooepidemicus spread

Direct contact

T or F: S. Equi zooepidemicus is zoonotic

True, but rare

What is pathogensis of S. Equi zooepidemicus

1. Adherence 2. Capsule- antiphagocytic 3. SzM protein- antiphagocytic, inhibits complement 3. Secrete toxin enzymes 4. Superantigens—> MHCII and T cell binding—> cytokine storm

What type of T cell is secreting pro-inflammatory cytokines

Helper T cells

How do you diagnose S. Equi zooepidemicus

1. Culture- gram positive streptococci, Beta-hemolysis, histopathology 2. PCR detection of SodA

What do you expect to see on culture of S. Equi zooepidemicus

Gram positive streptococci, beta-hemolysis

What is the treatment for S. Equi zooepidemicus

Antibiotics- B-lactams

What organism causes fading puppy syndrome, secondary pneumonia and neonatal septicemia

Streptococcus canis

How do you dx Streptococcus canis

1. Culture- gram positive streptococci, beta-hemolysis

What do you expect to see on culture of S. Canis

Gram positive streptococci and B-hemolysis

What is tx for S. Canis

If infectious- antibiotics- B-lactams

Which organism can cause meningitis in pigs

Streptococcus suis

S. Suis most often occurs in what pigs

Young post weaned pigs

What are the earliest clinical signs of S. Suis

Fever accompanied by septicemia

What are the clinical signs of meningitis caused by S. Suis in pigs

Ears back, eyes squinting, unusual stances, convulsions, other neurological signs

What lesions are associated with S. Suis

Lymphadenopathy, meningitis, arthritis, endocarditis

How is S. Suis transmitted

Healthy carrier sows and their offspring because S. Suis is prevalent in oral cavity and vaginal canal

What stereotype of S. Suis is most virulent and most frequently isolated from diseased pigs

Stereotype 2

How do you identify the serotypes of S. Suis

Capsule polysaccharides

What is the pathogensis of S. Suis

1. Enter upper respiratory tract 2. Adhesins 3. Proteins that allow immune evasion - S. Suis adenosine synthase- inhibits PMN activity - IgG degrading enzymes - Factor H-binding surface protein: inhibits phagocytosis

What proteins in S.suis allow immune evasion and what do they do

1. S. Suis adenosine synthase (Ssads): inhibit PMN activity—> inhibit neutrophils 2. IgG degrading enzymes 3. Factor H binding surface proteins: inhibits phagocytosis

How does S. Suis spread to other tissues

Hematogenous

How do you diagnose S. Suis

1. Gram positive streptococci 2. Alpha hemolysis on blood agar 3. Histopathology

What do you expect to see on culture of S. Suis

Gram positive streptococci and alpha- hemolysis

What is tx for S. Suis

Antibiotics for meningitis: B-lactams

T or F: S. Suis is zoonotic

True

What is answer in photo