5.1 Gram Positive Aerobic Cocci

Question 1

what are the 3 types of gram positive aerobic cocci

Answer 1

staphylococcus, streptococcus, enterococcus

Question 2

how is catalase a virulence factor for some gram positive aerobic cocci

Answer 2

prevents oxidative damage by converting hydrogen peroxide to water and oxygen

Question 3

For the 3 gram positive aerobic cocci, what are the results of the catalase test:

Answer 3

Staphylococcus: positive
Streptococcus: negative
Enterococcus: negative

Question 4

T/F most staphylococcus species are pathogenic

Answer 4

F: mostly non-pathogenic

Question 5

where is staphylococcus present

Answer 5

commensal of skin and exposed mm.; also an opportunist

Question 6

what types of infections does staphylococcus spp. cause

Answer 6

purulent and necrosis

Question 7

does staphylococcus survive well or poorly in the environment

Answer 7

well

Question 8

what are the 3 staphylococcus species of interest (pathogenic)

Answer 8

S. aureus; S. pseudointermedius (SIG); S. hyicus

Question 9

name a disease caused by the following and ID what species:
S. aureus
S. pseudointermedius
S. hyicus

Answer 9

S. aureus: mastitis (cows), bumblefoot (chickens)

S. pseudointermedius: pyoderma, UTI (dogs and cats)

S. hyicus: exudative epidermatitis (greasy pig disease - pigs)

Question 10

what is the characteristic appearance of S. aureus infection and what is a very common infection

Answer 10

pus, necrosis; UTIs

Question 11

Is S. aureus zoonotic

Answer 11

Y

Question 12

S. aureus is responsible for what important condition in humans

Answer 12

toxic shock syndrome

Question 13

what does MRSA stand for and what does it mean

Answer 13

Methicillin Resistant Staphylococcus Aureus; means that the bacteria is resistant to all β-lactams

Question 14

what is the major and most common opportunistic pathogen of dogs

Answer 14

S. pseudointermedius

Question 15

is S. pseudointermedius zoonotic

Answer 15

Y

Question 16

name some types of diseases caused by S. pseudointermedius in dogs

Answer 16

otitis externa, pyoderma, UTIs, metritis, vaginitis

Question 17

what does MRSP stand for and what does it mean

Answer 17

Methicillin Resistant Staphylococcus Pseudointermedius; means MULTIRESISTANT, not just to β-lactams….

Question 18

what is the causative agent of exudative epidermitis in pigs? what age group does it commonly affect

Answer 18

Staphylococcus hyicus; young pigs

Question 19

what do we use to differentiate the pathogenic strains of Staphylococcus

Answer 19

MALDI-TOF MS

Question 20

how do we treat and prevent staphylococcus infections

Answer 20

prevention: good hygeine, protocols; asepsis

treatment: perform susceptibility testing to choose an antimicrobial; give antimicrobials and treat primary cause

Question 21

what is the characteristic appearance of streptococcus

Answer 21

chains of cocci

Question 22

where is streptococcus

Answer 22

commensal of mucous membranes (NOT skin)

Question 23

does streptococcus survive well or poorly in the environment

Answer 23

poorly

Question 24

what kind of infections does streptococcus cause

Answer 24

pyogenic

Question 25

what are the 5 main species of streptococcus and what species do they have specificity for

Answer 25

1) S. equi (horses) 2) S. zooepidemicus (horses) 3) S. agalactiae (cattle) 4) S. suis (pigs and humans) 5) S. canis (dogs, cats)

Question 26

what is a key virulence characteristic of streptococcus species

Answer 26

β-hemolysis: lysis of RBCs surrounding the colony

Question 27

What are the 2 types of hemolysins

Answer 27

O: inactive in presence of oxygen S: stable in presence of oxygen

Question 28

what are M proteins and what type of gram positive aerobic cocci contains them

Answer 28

antiphagocytic surface proteins; streptococci

Question 29

what are the 3 main virulence factors of streptococcus spp.

Answer 29

1) Beta-haemolysis 2) M protein 3) teichoic acid

Question 30

what are three characteristics of streptococcus infection

Answer 30

1) pus producing 2) spread locally 3) septicemia in immunocompromised

Question 31

what pathogen causes strangles outbreaks in horses and what is the characteristic appearance

Answer 31

Streptococcus equi; abscesses in lymph nodes of head and neck

Question 32

how do you treat strangles outbreaks caused by S. equi

Answer 32

- identify guttural pouch carriers and infected horses - isolation, quarantine, cleaning, disinfection - treat early with penicillin - give vaccine

Question 33

what is "the" cause of opportunistic purulent infections in horses

Answer 33

S. zooepidemicus

Question 34

what can happen to a foal infected with S. zooepidemicus if no colostrum was given

Answer 34

septicemia (think back to the point that it usually causes local spread but causes sepsis if no antibodies are present)

Question 35

what does S. canis cause in dogs and cats? what are 2 major conditions caused by S. canis that also can occur in people (from a different pathogen)

Answer 35

opportunistic purulent infections: UTIs, wound infections, otitis externa, mastitis, necrotizing fasciitis, toxic shock

Question 36

what is the primary pathogen of the udder of cattle and what does it cause

Answer 36

Streptococcus agalactiae; contagious mastitis and subclinical mastitis

Question 37

a cow presents with abnormal udders. looking from behind, one quarter is large and one is small. you suspect that ___________, a major subclinical mastitis agent of cows, is present in what quarter

Answer 37

Streptococcus agalactiae; the smaller quarter (it causes fibrosis and atrophy)

Question 38

where is streptococcus suis found and what type of pathogen is it

Answer 38

in the tonsils; primary pathogen

Question 39

what age group is most affected by S. suis

Answer 39

weaner pigs

Question 40

are carriers a problem with S. suis control?

Answer 40

yes - hard to detect

Question 41

polyserositis, fibrinohaemorrhagic pneumonia, arthritis and endocarditis in weaner pigs is commonly caused by

Answer 41

S. suis

Question 42

T/F antimicrobial susceptibility testing should be done if you identify streptococcus species but not staphylococcus species

Answer 42

F; other way around; staphylococcus spp. commonly resistant

Question 43

what is a concern when you want to send a sample of streptococcus to a lab and why

Answer 43

transport media needed; they dont like to dry; they normally live in mucosa of animals

Question 44

what is a good antimicrobial to choose when you identify an infection caused by streptococcus in an animal

Answer 44

penicillin G

Question 45

what type of bacteria are enterococcus

Answer 45

facultative anaerobes, low grade opportunist

Question 46

enterococcus spp. cause diverse infections, such as:

Answer 46

- mastitis - wound infections - UTIs - nosocomial infections

Question 47

what bacteria is the leading cause of nosocomial infection

Answer 47

enterococcus

Question 48

what species of enterococci is VRE

Answer 48

vancomycin resistant enterococci refers to E. faecium (NOT E. faecalis or E. ceconium)

Question 49

T/F resistance is a problem with enterococci spp.

Answer 49

T; they are part of the ESKAPE group