Streptococcus Flashcards
Oxygen Metabolism?
Facultative Anaerobe
Where does it reside?
Mucous membranes, part of normal flora
Virulence Factors:
HEMOLYSINS
Are alpha-hemolysins pyogenic?
NO - beta-hemolysins are generally pyogenic
Alpha/non-hemolytic are not pyogenic
How do you classify a streptococcus infection (2 uses)
Lancefield classification and type of Hemolysis
What is the Lancefield classification based on?
It is based on cell wall carbohydrates
What group DOES NOT react with lancefield?
Viridans Group - makes ID difficult
S. pyrogenes - Group A Streptococcus - What hosts does it infect?
Humans (Scarlet fever) and Cattle (mastitis and skin infections)
What species of Streptococcus are zoonotic?
S. Canis and S. Iniae
What are the host(s) for S. canis ?
TYPICALLY puppies and kittens
Group G streptococcus infection
What type of S. suis is most often seen clinical case in pigs, and most predominant isolate from humans?
Type 2
T/F: S. suis affects adult/geriatric pigs?
False: S. suis affects weaning and growling pigs
What species does S. iniae infect?
FISH
What are the clinical signs associated with S. iniae infections?
Meningoencephalitis, myocarditis, epicarditis, perineuritis
T/F: both strains of S. iniae are virulent and commensal?
TRUE
S. Porcinus causes what clinical signs in pigs?
Jowl Abscesses
S. pneumonia causes what condition in guinea pigs and rodents?
Pneumonia
What does S. pneumoniae cause in humans?
Pneumonia, septicemia, and meningitis
What animals act as carriers for S. pneumoniae?
Domestic Pets
What disease does E. Equi subsp. equi cause?
Strangles - abscess formation in regional lymph nodes
How to distinguish S. equi subsp. equi?
Group C Streptococcus; Beta-hemolytic
Marked mucoid appearance from abundant hyaluronic acid capsule
S. equi subsp. equi causes what kind of infections?
Contagious Upper Respiratory Tract Infection (with abscess formation)
Mortality is low
How is S. equi subsp. equi transmitted?
DIRECT CONTACT with horse shedding bacteria
INDIRECT - with contaminated environments
Which age group is most susceptible to S. equi subsp. equi infection?
<2 years old (aka weaned foals/yearlings); (<4 months are protected by maternal AB’s)
S. equi subsp. equi Virulence Factors
Hyaluronic Acid Capsule and M protein
When do clinical signs for S. equi subsp. equi appear?
3-14 days after exposure as nasal discharge/cough (URI)
When do you typically see lymph node abscesses with S. equi subsp. equi?
Wishing 2 weeks of initial signs (submandibular and retropharyngeal)
S. equi subsp. equi complications
Disseminated infection (bastard strangles)
Purpura hemorrhagica
Guttural Pouch Empyema
Guttural Pouch Chondroids
What is Guttural Pouch Empyema?
Accumulation of purulent material in guttural pouch from lymphatic drainage and rupture into pouch.
Secondary infection to URI
What are Guttural Pouch Chondroids?
An accumulation of soft or hard “stone-like” concretions in one/or both pouches
Assoc. with chronic Empyema
Is S. equi subsp. equi a reportable disease?
YES - quarantine animal
Which antibody do you test for with S. equi subsp. equi?
M protein
What is the mechanism for S. equi subsp. equi killed vaccine?
Given IM - Used in pregnant mares/foals to maintain high levels of ANTI M PROTEIN opsonizing Ab’s
Live vaccine for S. equi subsp. equi is given through which method? IM, SubQ, or Intranasal?
Intranasal - stimulates mucosal immunity
Staphylococcus, Streptococcus, and Enterococcus are all considered what type of bacteria?
Gram Positive Cocci
