LAB 5 - Aerobic GPB Flashcards
bacteria in this category
Listeria
Gardnerella
Bacillus
Corynebacterium
Erysipelothrix
Arcanobacterium
frequent lab contaminants as they are widely distributed in nature
Bacillus sp.
Most virulent Coryne sp
C. diphtheriae when it produces a potent cytotoxic enterotoxin
signature grey-white pseudomembranes
T or F. L. monocytogenes is both a human and animal pathogen
T!
L. monocytogenes in clinical diseases
- encephalitis, meningitis, septicemia in the elderly and immunocompromised
- influenza-like bacteremic illness in pregnant women => infection of fetus
cold enrichment might be needed for isolation of this organism
L. monocytogenes (4C)
GPB, non-spore-forming that shows long filaments
E. rhusiopathiae
E. rhusiopathiae skin condition primarily on hands but can disseminate and cause this
endocarditis
Similar to Strep throat
A. haemolyticum
- 10 to 30 y/o
- penicillin-resistant
- rash resembles scarlet fever and pharyngeal pseudomembranes resembles those seen in diphtheria
G. vag
polymicrobial syndrome without inflammation
B. cereus test results
- cat +
- EYA lecithinase +
- spore stain +
Lacto test results
- cat -
- few sp microaerophillic
L. monocytogenes test results
- cat +
- BEA +
- TSI A/A sick yell
- TSB motility RT = tumbling; neg at 35C
Erysipelothrix sp. test results
- cat -
- BEA -
- TSI A/A H2S ( weak; long time)
A. haemolyticum test results
cat -
CAMP inhibition test +
T or F. The three C. diphtheriae biotype are only found in humans
T!
gravis, mitis, intermedius
where is diphtheria most common isolated from?
throat (pharyngeal) swabs
- can also be kin lesions, nasal and ear swabs
Media for C. diphtheriae
- 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
T or F. Coryneform or dips are more pleomorphic and irregularly sized than true C. diphtheriae
F!!! pathogen is more pleomorphic
black eschar
skin necrotic lesions
B. anthracis
B. anthracis and B. cereus common characteristics
- ox neg
- cat and lecithinase pos
- produce acid from glucose
T or F. B. anthracis is susceptible to penicillin disc test while other Bacillus sp. are resistant
T
usual specimens for isolation of Listeria
blood, CSF, amniotic fluid
Listeria tests
catalase pos
bile esc pos
bile hydrolysis pos
CAMP pos
Which organisms is non-hemolytic on sheep BAP
GVag (need human BAP)
48 hrs in 5-10% CO2
T or F. GVag is hippurate hydrolysis spos
T
actinomycetes
- nocardia and streptomyces
- slow growers (4 wks in CO2)
- branching filaments ( nocardia has fragmentation into bacilli and occi)
- nocardia is partial acid fast
