Lecture 9 - Streptococcus Flashcards
What type of bacteria is streptococcus based on behavior?
Pyogenic
What are streptococcus infections associated with?
Suppuration and Abscess formation
What are the two other genera of streptococcus?
Enterococcous + Peptostreptococcus
What is another name for peptostreptococcus?
Peptoniphilus
What type of pathogen is enterococcus?
Opportunistic
What is the oxygen preference of Peptoniphilius?
Strict anaerobes
Why is it hard for AB’s to get to streptococcus infections?
Abscess formation causes the infection to be walled off
What is the basis of lance field scheme of classification?
Antigenicity of a cell wall carbohydrate, known as the C substance
What is GAS composed of?
NAG + Rhamnose
What are the six significant streptococcal pathogens?
Pyogenes Agalactiae Enterooccus faecalis Equi equi Suis Ubers
What is the hemolytic pattern of S. pyogenes?
Beta
What is the hemolytic patter of S. uberis?
Alpha
What is the hemolytic pattern of S. equi spp. equi?
Beta
What is the hemolytic pattern of S. Agalactiae?
Beta
What is the hemolytic pattern of Enterococcus faecalis?
Alpha + Gamma
What is the hemolytic pattern of S. Suis?
Alpha
What is the basic disease process that goes with S. pyogenes?
Mastitis + Lymphangitis
What is the basic disease process that goes with S. aglactiae?
Chronic mastitis
What is the basic disease process that goes with S. equi spp. equi?
Strangles
What is the basic disease process that goes with S. Suis?
Meningitis
What is the basic disease process that goes with S. Uberis?
Mastitis
What is the basic disease process that goes with Enterococcus faecalis?
Oppurtunistic infections
What kind of hemolysis occurs with alpha?
Partial
What kind of hemolysis occurs with beta?
Complete
What kind of hemolysis occurs with gamma?
None
What are the oxygen standards of streptococcus?
Obligate fermentative, but survives in O2
What is the growth characteristic of streptococcus?
Fastidious
What type of medium does streptococcus like to grow on?
Blood agar
What temperature does streptococcus prefer?
Mesophile - 35 to 37 degrees C
What is streptococcus’ preference towards CO2?
Capnophile - like CO2 levels at 2 to 10%
Is streptococcus gram + or - ?
Postive
What are the general arrangement of streptococcal cells?
Chains or Diploid
What shapes do streptococcal cells tend to be?
Spheres or Oval
What are the catalase properties of streptococcus?
Negative
When does strep grow in chains?
Broth culture
When does strep tend to grow in diploid form?
Clinically
What are the virulence factors within the cell envelope in Strep?
M protein + Peptidoglycan + Protein F/LTA + Capsule
What is the major virulence factor for Strep?
M protein
What does M protein do?
Protects cell from phagocytosis
Inhibits activation of complementation
Allows for attachment to host cell
How does M protein inhibit complement activation?
Binds to Factor H
What does peptidoglycan do?
Pyrogen
What does Protein F and LTA allow for?
Tissue tropism
What does Protein F do?
Bind fibronectin surface host cells
What does LTA do?
Attaches to pharyngeal epithelium
What is the capsule of Strep composed of?
Hyaluronic acid OR Polysaccharides
What does the capsule allow the Strep cell to do?
Appears as “self” to immune system, inhibiting phagocytosis also giving smooth appearance to colony
What are the virulent enzymes and exotoxins within Strep?
Hemolysins C5a peptidase Streptodornase Streptokinase Hyaluronidase Spe (streptococcal pyrogenic factor) Siderophores
What are the two types of hemolysin?
Steptolysin O + S
What does streptolysin O do?
Oxygen labile
Destroys RBCs and WBCs
Immunogenic
What does Streptolysin S do?
Destroy RBC + WBC
When is there hemolysis with strep O?
Deep cuts
When is there hemolysis with strep S?
Surface
What does C5a peptidase do?
Degrade C5a - Disrupts recruitment + activation of phagocytic cells
What does Streptodornase do?
Degrades DNA - reduces viscosity = purulent exudates
What does streptokinase do?
Generates plasmin - Breaks down fibrin + other clot forming proteins
What does Hyaluronidase do?
it is a mucolytic enzyme
Splits and reduces the viscosity of HA – allowing for easier spread of infection
How many types of streptococcal pyrogenic exotoins are there?
3 - A, B, C
Which of the Spe’s are superantigens?
A
What does SpeA cause?
Massive cytokine release + Tissue damage
Responsible for toxemia
What are Strep with SpeA called?
Lysogenzed strains
What do siderophores do?
Iron chelating molecules
What are the two common Strep’s that affect horses?
Equi
Spp. Equi
Spp. Zooepidemicus
What is the general effect of spp. Equi?
Strangle s
What is the general effect of spp. Zooepidemicus?
Pneumonia
What are the common Strep’s that affect pigs?
Suis
Types 1, 2, 9, 14
What S. Suis type is responsible for Menigitis?
Type 2
What S. Suis is responsible for Polyserositis and septicemeia?
Types 1, 9, 14
What types of Strep commonly affect cow?
Agalactiae + Dysgalactiae + Uberis
What lymph nodes are affected in strangles?
Mandibular + Retropharyngeal + Intermandibular
What are the characteristics of strangles?
Upper respiratory tract
Nasal discharge
Abscessed LN
What horses are susceptible to strangles?
All, but primarily seen in young
How is strangles transmitted?
Purulent exudate
Chronic carrier w/ bacteria in guttural pouch
How does infection occur with strangles?
Enter nose or mouth
Attach to cilia of tonsils
Move into lymph nodes - multiples there
What causes abscesses in LN with strangles?
Influx of neutrophils
What are the virulence factors in strangles?
Peptidoglycan Hyularonic capsule M protein Streptokinase + Streptolysin S Lysogens
What does the peptidoglycan in strangles do?
React with C1 in complement pathway
What does the capsule and M protein do in strangles?
Inhibit phagocytosis
Alone, what does M protein do in strangles?
Prevent Alternate + Classical complement
What is the incubation period of strangles?
3-6 days
What is the length of strangles infection if it is uncomplicated?
5 to 10 day s
What are the possible outcomes of strangles?
Purpura hemorrhagica vasculitis
Type III Hypersensitivity
Bastard strangles
How long does it take for a type III reaction to occur with strangles?
1 to 3 weeks, delayed due to time needed to make Ab’s
What is bastard strangles?
Meatstatic absecesses
What is the mortality rate with Strangles?
5%
How can you diagnose strangles?
Nasal discharge
LN aspiration
PCR
IsoAMP
What do the S. Equi spp. Equi colonies look like?
Mucois, 4 mm diameter, B-Hemolytic on BAP
Why would you use PCR to ID S. Equi spp. Equi?
Tell the difference between equisimilis and zooepidemicus
Detect those showing no signs
What is the treatment for strangles?
Supportice
Hot packs + drain LN
What vaccines are used for strangles?
Cell wall extract
Live, noncapsulated, attenuated strain
When might you get a reaction to the vaccine?
Currents signs of strangles seen
– or –
Disease occurred in the past year
What might you need to remove from the horse to end ongoing strangles infection?
Chondrioids (hardened purulent debris)
What lancefield group is S. Suis?
D
What pathologies are linked to S. suis? (5 of them)
Meningitis Endocarditis Neonatal death Bronchopneumonia Septicemia
Which S. suis is most prevalent?
Type 2
Where is S. suis located in asymptomatic pigs?
Tonsillar tissues
When is meningitis normally seen?
Nursing or recently weaned pigs
What are the signs of meningitis in pigs?
Continual movement of eyes
Shivering + Shaking + Paddling + Convulsions
When do you see outbreaks of S. Suis?
Intensely reared pigs
Overcrowding + Poor ventilation + Stress
What happens when sows transmit S. Suis to litter?
Neonatal death
– or –
Carrier animals
What happens when humans come into contact with S. Suis?
Systemic infection
Meningitis - most common symptom
What is S. Suis susceptible to?
Penicillin/ampicillin
When is prophylactic treatment used for S. Suis?
Sows - when farrowing
Piglets - first 2 weeks
What kind of mastitis does S. agalactiae cause?
Contagious
What kind of mastitis does S. dysgalactiae cause?
Contagious + Environmental
What kind of mastitis does S. uberis cause?
Environmental
Where is S. agalactiae found in the cow?
Milk ducts
Where is S. dysgalactiae found in the cow?
Buccal cavity + Genitalia + Skin of mammary gland
Where is S. uberis found in the cow?
Organic bedding
Normal to find on Skin + Tonsils + Vaginal mucosa
What happens to milk production with S. agalactiae?
No galactose/milk
What happens to milk production with S. dysgalactiae?
Impaired milking
Which strep is the major cause of clinical mastitis in cows?
S. uberis
What do you see with Strep induced mastitis?
Inflammation of mammary tissue
Clots in milk
Increase in SSC
What is the haemolysis, CAMP results, hydrolysis, and lancefield group of S. agalactiae?
Beta
Camp +
Hydrolysis -
Lancefield B
What is the haemolysis, CAMP results, hydrolysis, and lancefield group of S. dysgalactiae?
Alpha
Camp -
Hydrolysis -
Lancefield C
What is the haemolysis, CAMP results, hydrolysis, and lancefield group of S. Uberis?
Alpha
CAMP -
Hydrolysis +
No lancefied group
What does CAMP factor do?
Enhances B-hemolysis
What is the easiest strep to treat in cows?
S. agalactiae
What AB’s should be used to treat S. agalactiae?
Cephalosporins + Penicilin
Why dont you want to use macrolides in treating Strep infections in cows?
long withdrawal times
What are the Streps that can affect cats and dogs?
Canis
Equis spp. Zooepidemicus
Enterococcus faecium + faeclis
What is the primary step infection seen in dogs and cats?
S. Canis
What does S. Canis cause?
Necrotizing fascitis + Toxic Shock Syndrome
What is the characteristics of S. Canis in cat neonates?
infected by the queen
Weight loss + Swollen infected Umbilicus
Death
What are the characteristics of S. Canis in juvenile cats?
Lymphadenitis
What is the route of infection in neonate kittens?
Umbilical cord to peritoneum or ductus venosus
What are the clinical manifestation in neonatal puppies with S. canis?
Bacteremia + Septicemia + Polyarthritis + FPS
What are the clinical manifestation in older dogs with S. canis?
Rapidly progressing systemic infection
TSS
NFM