strep, entero, other catalase-neg, gram-pos cocci

Question 1

formerly known as groud D strep

Answer 1

enterococci

Question 2

previously classified as group N strep

Answer 2

lactococci

Question 3

17 genera of catalase-neg, gram-pos cocci including

Answer 3

streptococcus, aerococcus, lactococcus, leuconostoc, pediococcus spp.

Question 4

weak false-pos catalase reactions can be seen when

Answer 4

growth is taken from media containing blood, owing to the peroxidase activity of hemoglobin

Question 5

streptococcal cells are more likely to appear in chains when grown in

Answer 5

broth cultures

Question 6

growth is poor on nutrient agar such as

Answer 6

trypticase soy agar

Question 7

media enriched with blood or serum

Answer 7

growth is more pronounced

Question 8

partial lysis of rbc; greenish discoloration

Answer 8

alpha

Question 9

complete lysis of rbc; clear area around colony

Answer 9

beta

Question 10

no lysis of rbc; no change in agar

Answer 10

nonmeolytic

Question 11

some isolates belonging to the viridans group produce

Answer 11

wide-zone or a’ hemolysis

Question 12

pyogenic streptococci isolated frequently from humans include

Answer 12

streptococcus pyogenes, strep. agalactiae, strep. dysgalactiae subsp. equisimilis, strep. anginosus group

Question 13

attached to the peptidoglycan of the cell wall of pyogenes and extends to the cell surface

Answer 13

m protein

Question 14

s. pyogenes colonizes

Answer 14

throat and skin on humans, making these sites the primary sources of transmission

Question 15

most common serotype seen in pharyngitis

Answer 15

M1

Question 16

adhesion molecules that mediate attachment to host epithelial cells

Answer 16

lipoteichoic acid, protein F

Question 17

s.pyogenes secretes four diff. DNases

Answer 17

A, B, C, D (most common is DNase B)

Question 18

responsible for hemolysis on SBA plates incubated anaerobically; lyses leukocytes, platelets, other cell as well as rbc

Answer 18

streptolysin O

Question 19

oxygen stable, lyses leukocytes, and is nonimmunogenic; hemolysis seen around colonies that have been incubated aerobically

Answer 19

streptolysin S

Question 20

spreading factor, is an enzyme that solubilizes the ground substance of mammalian connective tissues

Answer 20

hyaluronidase

Question 21

cause a red spreadin rash referred to as scarlet fever, caused by

Answer 21

streptococcal pyrogenic exotoxins, formerly called erythrogenuc toxins

Question 22

infections resulting from s.pyogenes include

Answer 22

pharyngitis, scarlet fever, skin or pyodermal infections

Question 23

most common clinical manifests of GAS infection are

Answer 23

pharyngitis and tonsillitis

Question 24

“strep throat” is most often seen in

Answer 24

children between 5 and 15 yrs of age

Question 25

skin or pyodermal infections with GAS result in

Answer 25

impetigo, cellulitis, erysipelas, wound infection or arthritis

Question 26

a localized skin disease, begins as small vesicles that progress to weeping lesions

Answer 26

impetigo

Question 27

rare infection of the skin and subcutaneous tissues observed frequently in elderly patients; characterized by an acute spreading skin lesion that is intensely erythematous

Answer 27

erysipelas

Question 28

can develop following deeper invasion by streptococci; can be serious or life-threatening with bacteremia or sepsis

Answer 28

cellulitis

Question 29

patients with peripheral vacular disease or diabetes, cellulitis may lead to

Answer 29

gangrene

Question 30

characterized by a diffuse red rash that appears in the upper chest and spreads to the trunk and extremities; rash disappears over the next 5 to 7 days and is followed by desquamation

Answer 30

scarlet fever

Question 31

an invasive infection characterized by rapidly progressing inflammation and necrosis of the skin, subcutaneous fat and fascia

Answer 31

necrotizing fasciitis

Question 32

polymicrobial infection from which aerobic and anaerobic bacteria are recovered is categorized as

Answer 32

type 1 NF

Question 33

consists of only GAS

Answer 33

type 2 NF

Question 34

gas gangrene or clostridial myonecrosis

Answer 34

type 3

Question 35

other terms for NF aside from flesh-eating bacteria

Answer 35

suppurative fasciitis, hospital gangrene, necrotizing erysipelas

Question 36

a condition in which the entire organ system collapses, leading to death

Answer 36

streptococcal toxic shock syndrome

Question 37

most common strains associated with streptococcal TSS

Answer 37

isolates with M1 and M3

Question 38

two serious complications, or sequelae, of GAS disease are

Answer 38

rheumatic fever, acute glomerulonephritis

Question 39

more common in children than in adults; sometimes occur after cutaneous or pharyngeal infection

Answer 39

acute glomerulonephritis

Question 40

drug of choice for GAS

Answer 40

penicillin

Question 41

for patients allergic to penicillin this can be used

Answer 41

erythromycin

Question 42

proper sampling for strep pharyngitis

Answer 42

tongue should be depressed and the swab rubbed over the posterior pharynx and each tonsillar area

Question 43

is inoculated and streaked for isolation; incubation should be at 35 degrees C either in ambient air or under anaerobic conditions

Answer 43

SBA agar plate

Question 44

important virulence factor in group b strep

Answer 44

capsule

Question 45

most significant component of the capsule and critical virulence determinant

Answer 45

sialic acid

Question 46

products produced by s.agalactiae include

Answer 46

hemolysin, CAMP factor, neuraminidase, DNase, hyaluronidase, protease

Question 47

two clinical syndromes are associated with neonatal GBS disease

Answer 47

early-onset infection (< 7 days old) late-onset infection (at least 7 days old to about 3 months old)

Question 48

vertical transmission from the mother

Answer 48

early onset infection 80%

Question 49

early-onset infection often manifests as

Answer 49

pneumonia and sepsisa

Question 50

late-onset infection manifests as

Answer 50

meningitis and sepsis

Question 51

in adults, the infection affects two types of patients

Answer 51

1st is a young, previusly healthy woman who becomes ill after childbirth or abortion; endometritis and wound infection 2nd is an elderly person with serious underlying disease or immunodeficiency

Question 52

drug of choice for gbs

Answer 52

penicillin, tho less susceptible than gas

Question 53

s.agalactiae is sensitive to

Answer 53

penicillin and cephalosporin

Question 54

gbs grows on sba as

Answer 54

grayish white mucoid colonies surrounded by a small zone of b-hemolysis; forms short chains in clinical spx and longer chains in culture

Question 55

most useful tests are

Answer 55

camp test and positive hippurate hydrolysis

Question 56

detection of bgs in pregnant women is accomplished by

Answer 56

collecting vaginal and rectal material with swabs between 35 and 37 weeks of gestation

Question 57

samples should be inoculated into selective broth such as

Answer 57

todd-hewitt broth containing 10ug/ml colistin and 15ug/ml nalidixic acid

Question 58

the inoculated media are incubated ay

Answer 58

35 degrees C for 18to24 hrs before being subcultured to SBA

Question 59

can be substituted for lim or transvag broth

Answer 59

strepb carrot broth

Question 60

b-hemolytic gbs produce an orange or red pigment in scb after

Answer 60

incubation for 6 hrs

Question 61

the large colony-forming isolates with group c and g belong to the

Answer 61

subspecies s.dysgalactiae subsp. equisimilis

Question 62

the small-colony-forming b-hemolytic isolates with group c and g antigens belong to the

Answer 62

s. anginosus group

Question 63

spectrum of infections resembles s.pyogenes and includes

Answer 63

upper respiratory tract infections, skin infections, soft tissue infections, invasive infections such as NF