Lecture 8 Flashcards
What biocontainment level does Streptococcus enterococcus have?
2
Is Streptococcus enterococcus gram negative or positive?
Postivie
Describe the metabolism of Streptococcus enterococcus
Aerobic or facultative anaerobe
Where is Streptococcus enterococcus found?
Normal microbiota component - resp, mucous membranes & intestinal tract
What are the virulence factors of Streptococcus enterococcus ? (5)
Exotoxins
Phage mediated superantigen
Capsule - prevents phagocytosis
Hemolysins - cytotoxic to eukaryotic cells
CAMP factor - pore forming toxin
What is the virulence factor of Streptococcus pyrogenes?
Exotoxins
What is the virulence factor of Streptococcus canis?
Phage mediated superantigen
What disease does Streptococcus agalactiae cause in bovine?
Contagious Bovine Mastitis
What is the cause of disease of contagious bovine mastitis caused by Streptococcus agalactiae?
Infected cows are source of infection
Breakdown of biosecurity - teat hygiene, cleaning milk equipment, hand washing
How do you tx contagious bovine mastitis caused by Streptococcus agalactiae?
Intra-mammary a/bs
Biosecurity management - teat hygiene, clean milk equipment, hand washing
What are the symptoms of contagious bovine mastitis caused by Streptococcus agalactiae?
Mainly subclinical
Will see decres milk production
What disease does Streptococcus dysgalactiae cause?
Envr Bovine Mastitis
What is the cause of disease of Streptococcus dysgalactiae?
Contamination of the teats from the envr via bedding in combo with some physical damage (machine, insect bite wound etc.) to the teat allowing infection to occur
Management issue of bedding & envr
What are the symptoms of Streptococcus dysgalactiae infection causing envr bovine mastitis?
Subclinical
How do you treat envr bovine mastitis caused by Streptococcus dysgalactiae?
Management improvements - improve cleanliness, bedding & access to shelter
Dry cow treatment
Teat sealer (prevent access of bacteria into teat)
What disease does Streptococcus equipment subsp equipment cause?
Horse strangles
What symptoms are seen with horse strangles?
Abscessation of submandibular & retropharyngeal lymph nodes
How is horse strangles caused?
Contact with nasal secretions or discharges form ruptured lymph nodes or contact with contaminated fomites
What is the prognosis of horse strangles?
Highly contagious
Long term sequelae is possible:
Can get metastatic abscesses (bacteria get into blood & spread)
Purpura hemorrhagica - vasculitis secondary to deposition of immune-complexes
75% of horses have enduring immunity
How do you tx horse strangles?
Penicillin
How do you prevent horse strangles?
Isolation is key
Vaccines are available
What type of hypersensitivity rxn best describes purport hemorrhagica?
Type 3 - immune complex deposition
What spp does Streptococcus canis infect?
Dogs & cats
What are the symptoms of Streptococcus canis in cats?
Seen in kittens
Skin & soft tissue infections, abscesses
Resp infections
What is the tx for Streptococcus canis infections?
Penicillin
Phage superantigens which are expressed following exposure to flurorquinolones cause necrotizing fasciitis & toxic shock syndrome
Describe how the Streptococcus canis super antigen rxn occurs
A phage will introduce its DNA into Streptococcus canis
When exposed to fluroroquinolones the SOS response is triggered, the response that bacteria have to when their DNA is being damaged
An antigen is expressed which stimulates T cells
Results in cytokine release
Leads to hypotension/shock
What disease does Streptococcus suis cause?
Causes the following in pigs: Meningitis Arthritis Septicemia Sudden death
What is the prognosis for Streptococcus suis in pigs?
High case fatality rate
Early tx may be effective
What is the cause of infection of Streptococcus suis in pigs?
Assoc with moving pigs, over crowding & poor ventilation
Piglets acquire organism at farrowing from the sow & envr
What is the pathogenesis of Streptococcus suis?
Piglets acquire the organism from their mother at farrowing & the envr
The organism enters the body through the tonsils
Reaches submandibular lymph nodes
Once it reaches the bloodstream, it will cause septicemia
(most commonly seen in piglets but it can effect any age of pig)
Is Streptococcus suis zoonotic?
yes, those with high exposure to animals
Usually enters through cuts & scratches
What disease enterococcus cause in chickens?
Cause of mortality in chicks
Acute - septicemia (depression, ruffled feathers)
Subacute-chronic - depression, loss of condition, pyrexia
What is the cause of death of chicks due to Streptococcus?
Death is assoc with fecal contamination of eggs
How do you prevent Streptococcus in chickens?
Management strategies - present stress, disease, clean & disinfect
How do you tx Streptococcus in chickens?
Can tx with a/bs if caught early
Must be based on susceptibility test results, can cause a lot of intrinsic resistance
What disease does Enterococcus cause in dogs & cats?
Similar opportunistic disease to people, assoc with nosocomial infection (hospital acquired infections)
Systemic infections - bacteremia & endocarditis
Localized infections - abdominal cavity, genitourinary tract, soft tissue, respiratory tract
What disease does Enterococcus hire cause?
GIT infections in dogs & cats
How do you tx enterococcus in dogs & cats?
Resistance will greatly effect selection of tx
Need to know the spp
How do you collect samples for mastitis?
Milk sample
How do you collect samples for dermatitis/surface infections?
Swabs, pus, exudates
How do you collect samples for sepsis/death?
Whole animal
Culture of brain for Streptococcus suis meningitis
How do you collect samples for resp infections?
trans tracheal wash fluid
How do you handle streptococcus samples?
Generally pretty tough
Swabs should be sent with transport media
DO NOT FREEZE
How is Streptococcus identified in lab?
Commercial biochemical test panels
MALDI-TOF & NAAT + DNA sequencing
Is Streptococcus equipment subsp zooepidemicus zoonotic?
Transmission b/w dogs & horses by ingesting unpasteurized milk
Is Streptococcus canis zoonotic?
Yes
What tx do we need to avoid with Streptococcus canis?
Fluoroquinolone
What a/b is streptococcus resistant to?
cephalosporins
What a/b is best to tx Streptococcus?
Beta-lactam