LAB 5 - Aerobic GPB

Question 1

bacteria in this category

Answer 1

Listeria
Gardnerella
Bacillus
Corynebacterium
Erysipelothrix
Arcanobacterium

Question 2

frequent lab contaminants as they are widely distributed in nature

Answer 2

Bacillus sp.

Question 3

Most virulent Coryne sp

Answer 3

C. diphtheriae when it produces a potent cytotoxic enterotoxin
signature grey-white pseudomembranes

Question 4

T or F. L. monocytogenes is both a human and animal pathogen

Answer 4

T!

Question 5

L. monocytogenes in clinical diseases

Answer 5

• encephalitis, meningitis, septicemia in the elderly and immunocompromised
• influenza-like bacteremic illness in pregnant women => infection of fetus

Question 6

cold enrichment might be needed for isolation of this organism

Answer 6

L. monocytogenes (4C)

Question 7

GPB, non-spore-forming that shows long filaments

Answer 7

E. rhusiopathiae

Question 8

E. rhusiopathiae skin condition primarily on hands but can disseminate and cause this

Answer 8

endocarditis

Question 9

Similar to Strep throat

Answer 9

A. haemolyticum
- 10 to 30 y/o
- penicillin-resistant
- rash resembles scarlet fever and pharyngeal pseudomembranes resembles those seen in diphtheria

Question 10

G. vag

Answer 10

polymicrobial syndrome without inflammation

Question 11

B. cereus test results

Answer 11

• cat +
• EYA lecithinase +
• spore stain +

Question 12

Lacto test results

Answer 12

• cat -
• few sp microaerophillic

Question 13

L. monocytogenes test results

Answer 13

• cat +
• BEA +
• TSI A/A sick yell
• TSB motility RT = tumbling; neg at 35C

Question 14

Erysipelothrix sp. test results

Answer 14

• cat -
• BEA -
• TSI A/A H2S ( weak; long time)

Question 15

A. haemolyticum test results

Answer 15

cat -
CAMP inhibition test +

Question 16

T or F. The three C. diphtheriae biotype are only found in humans

Answer 16

T!
gravis, mitis, intermedius

Question 17

where is diphtheria most common isolated from?

Answer 17

throat (pharyngeal) swabs
- can also be kin lesions, nasal and ear swabs

Question 18

Media for C. diphtheriae

Answer 18

• Tellurite (cysteine tellurite agar, Hoyles agar, Tinsdale’s)
  > potassium tellurite (a salt) inhibits most normal flora of resp tract
  > turns black; GPC may turn black too
  > selective AND differential bc will have black halo around colonies if pathogenic
• Loeffler’s blood serum
  > enhance growth of C. diphtheria and metachromatic granule formation

Question 19

T or F. Coryneform or dips are more pleomorphic and irregularly sized than true C. diphtheriae

Answer 19

F!!! pathogen is more pleomorphic

Question 20

black eschar

Answer 20

skin necrotic lesions
B. anthracis

Question 21

B. anthracis and B. cereus common characteristics

Answer 21

• ox neg
• cat and lecithinase pos
• produce acid from glucose

Question 22

T or F. B. anthracis is susceptible to penicillin disc test while other Bacillus sp. are resistant

Answer 22

T

Question 23

usual specimens for isolation of Listeria

Answer 23

blood, CSF, amniotic fluid

Question 24

Listeria tests

Answer 24

catalase pos
bile esc pos
bile hydrolysis pos
CAMP pos

Question 25

Which organisms is non-hemolytic on sheep BAP

Answer 25

GVag (need human BAP) 48 hrs in 5-10% CO2

Question 26

T or F. GVag is hippurate hydrolysis spos

Answer 26

T

Question 27

actinomycetes

Answer 27

- nocardia and streptomyces - slow growers (4 wks in CO2) - branching filaments ( nocardia has fragmentation into bacilli and occi) - nocardia is partial acid fast