streptococcus

Question 1

streptococcus characteristics

Answer 1

• part of the normal microbiota of the host
• streptococci in resp tract and mucus membrane
• Gram-positive cocci
• aerobic or facultatively anaerobic
• fastidious
• level 2

Question 2

Virulence of streptococcus

Answer 2

• exotoxins
• phage mediated superantigen
• capsule
  hemolysins
  CAMP factor (pore formation)

Question 3

how is strep differentiated from staph?

Answer 3

catalase test

Question 4

how is strep grouped?

Answer 4

grouped by: hemolysis (alpha, beta, gamma) and Lancefield (A-G)

Question 5

S. pneumoniae

Answer 5

host: human, horses, pigs
disease: pneumonia

Question 6

S. agalactiae

Answer 6

host: cattle
disease: chronic mastitis, mainly subclinical
control: biosecurity, teat hygiene, many are penicillin-susceptible

Question 7

S. dysgalactiae

Answer 7

host: cattle
disease: acute mastitis, often subclinical
acquired: environmental, teat contamination
control: clean barn, good bedding, access to shelter
treatment: dry cow and teat sealer

Question 8

S. equi subsp equi

Answer 8

host: horses
disease: strangles
causes abscessation of submandibular and retropharyngeal lymph nodes
very contagious
control: isolate animals
treatment: penicillin, 75% become immune to future infection, vaccinate

Question 9

S. canis

Answer 9

host: cat, dog
disease: septicemia, wound infections

Question 10

S. equi subs zooepidemicus

Answer 10

hosts: horse, cattle, pig, poultry cats, dogs
disease: joint infection (H), mastitis (C), septicemia (P, P), resp infections (D, cat)
dogs and horses are zoonotic

Question 11

S. suis

Answer 11

host: pigs
disease: meningitis, arthritis, septicemia
causes high mortality
acquired from sow, environment, enters via tonsils
treatment early may be effective

Question 12

S. bovis

Answer 12

host: main = cattle, opportunistic in other species
disease ruminal acidosis, opportunistic infection
produces lactic acid decreasing pH kills other microbes = acidosis
acidosis leads to rumenitis that causes hepatic abscesses

Question 13

enterococcus spp. poultry

Answer 13

opportunistic infection
mortality in chicks - fecal contamination of eggs
control: barn management is key
treatment: antibiotics if caught early
must be based off of susceptibility test results

Question 14

enterococcus spp others

Answer 14

host: dog, cat, human
disease: opportunistic infections
causes: systemic (bacteremia, endocarditis), localized infections
treatment: beware AMR, intrinsic resistance, knowing which species of enterococcus is key