Streptococcus

Question 1

gram, shape, arrangement

Answer 1

-gram positive
-cocci
-chains

Question 2

respiration, motility, spore, catalse

Answer 2

-facultative anaerobe
-non motile
-non spore forming
-catalase negative

Question 3

growth requirements

Answer 3

-fastidious growth – requires nutritionally rich media
-cannot grow in high salt

Question 4

blood agar

Answer 4

-B – most pathogenic strep, complete hemolysis
-a – partial and incomplete hemolysis, green color, upper respiratory tract strep
-y – fecal strep, no hemolysis

Question 5

whaat selective media for isolation adn identification of strep

Answer 5

edward media

Question 6

serogrouping method for strep

Answer 6

lancefield serogrouping

Question 7

clincially important serogroups

Answer 7

A, B, C, D, E, G

Question 8

what hemolysis are most equine and canine isolates

Answer 8

beta hemolytic

Question 9

beta hemolytic strep

Answer 9

group A – S pyogenes (tonsilitis)
group B – S agalactiae
group C – S equi, equismullis, zooepidemicus, dysgalactiae
group E – S procinus (swine)
group G – S canis

Question 10

alpha hemolytic Strep

Answer 10

optochin sensitive – S pneumonaie
optochin resistant – S suis and viridans strept

Question 11

gamma hemolytic strep

Answer 11

group D – enterococcus, Strept bovis (S gallolyticus)

Question 12

what casues meningitis and pneumonia in children

Answer 12

S pneumoniae

Question 13

habitat

Answer 13

skin, upper respiratory, tonsils, digestive tract, lower urogenital tract, udder/teat duct

Question 14

transmission

Answer 14

-opportunisitc pathogen
-bacteria enter cuts, abrasions
-weakened immune system
-primary disease
-spread by direct contact, aerosol, fomites, ingestion (sometimes)

Question 15

structural compounds – lipoteichoic acid

Answer 15

-adhesion, cytotoxic for most host cells

Question 16

structural compounds – capsule (slime layer)

Answer 16

-prevents chemotaxis
-adhesion
-hide by deposition of host sialic acid residues
-prevent bacterial recognition by phagocytes
-prevent complement assisted opsonization

Question 17

structural compounds – M protein

Answer 17

-adhesion
-inhibition of phagocytic ingestion
-binds to Fc region of IgG
-prevents opsonization

Question 18

structural compounds – protein G

Answer 18

-compete with complement
-bind with Fc region of IgG
-prevent opsonization

Question 19

enzymes – nuclease (A, B, C, D)

Answer 19

-liquifaction of pus (uses pus to grow)
-DNAse activity (A, C) and RNAse activity (B, D) to destroy host cells and defenses

Question 20

enzymes – streptokinases

Answer 20

-conversion of plasminogen to plasmin, leads to digestion of fibrin
-lyse blood clots to escape and spread out

Question 21

enzymes – C5a peptidases

Answer 21

-destroy C’ chemotactic signals (C5a)
-blocks chemotaxis

Question 22

toxins – hemolysin (a, B, y)

Answer 22

-destroys RBCs, neutrophils, macrophages, platelets

Question 23

toxins – exotoxins (streptolysin O and S)

Answer 23

-hemolytic on blood agar
-kills phagocytes
-inhibit phagocyte attraction (inhibit chemotaxis)

Question 24

toxins – pyrogenic exotoxins (fever causing) (A, B, C)

Answer 24

-fever, strawberry rash
-cardiac and liver necrosis
-T cell division
-superantigen
-increase endothelium and blood brain barrier permeability

Question 25

4 directions strep advances from

Answer 25

-cutaneous -- pus, abscess -throat -mammary -urogenital

Question 26

emerging zoonotic strep from animals to humans

Answer 26

S suis (pig) S gallolyticus (chickens)

Question 27

strep pyogenes in humans

Answer 27

-scarlet fever -- pharyngitis -strep throat infection -lymph node and tonsil infection -strawberry rash -necrotizing skin fascilitis -flesh eating by pyrogenic exotoxins

Question 28

strep in horses

Answer 28

-throat infection = pharyngitis -pus accumulation in throat -generalized infection -reproductive tract infection -abortion, vaginitis, postpartum endometritis -strangles -S. dysgalatiae subspecies equisimilis -S. equi subspecies zooepidemicus -Streptococcus equi subspecies equi

Question 29

strep in pigs

Answer 29

-throat infection, porcine strangles, pharnygitis -pus in throat, jowl abscess (feeder boils) -contagious cervical lymphadenitis -generalized infection -deafness, blindness, meningitis, speticemia -pupura hemorrhagica on leg -gangrene down to foot -S. porcinus -- rare now -S. suis -- most common problem in pig industry -S. equi subspecies zooepidemicus (occasionally)

Question 30

strep in pets

Answer 30

-throat infection -- pet strangles -generalized infection -- septicemia, pneumoina, memnigitis -eye and ear -- blindness, otitis -reproductive tract -S canis -- major problem -S. equi subspecies zooepidemicus -- emerging problem -S. agalactiae, S. pneumoniae, S. suis, S. pyogenes -- occasional problem

Question 31

strep in ruminants

Answer 31

-S. uberis -- mastitis -S. dysgalatiae -- acute contagious/environmental mastitis, polyarthritis -S. agalatiae -- chronic contagious mastitis -Occasionally S. equi subsp. Zooepidemicus -- metritis (abortion), mastitis

Question 32

alpha hemolytic strep -- greening (viridians)

Answer 32

-S mitis, S mutans, S salivarius, S snguis, S miller -normal flora of oral cavity, intesinte, urethra -endogenous infection

Question 33

control

Answer 33

-hygiene, wellbeing, reducing stress, control of primary diseases -vaccine for S pneumoniae in humans

Question 34

which strep only causes bovine mastitis

Answer 34

S uberis