Non-Branching, NON-SPOREFORMING, Catalase-NEGATIVE, Gram -Positive Bacilli

Question 1

number of Erysipelothrix rhusiopathiae serovars that are considered to cause human infection

Answer 1

two (2)

serovar 1 and serovar 2

Question 2

Gardnerella spp are known to ferment the following molecules:

Answer 2

acetic acid

lactic acid

Question 3

a cell wall feature of Gardnerella spp.

Answer 3

cell wall is significantly thinner

contains LESS peptidoglycan than the typical gram positive bacteria

Question 4

the normal vaginal inhabitants

Answer 4

Gardnerella vaginalis

Lactobacillus spp

Question 5

role of Lactobacillus spp. in vaginal homeostasis

Answer 5

maintains vaginal acidic pH (proper pH)

– metabolize glucose to lactic acid

Question 6

a Lactobacillus-like organism that is isolated from patients with clinical symptoms of endocarditis

Answer 6

Weissella confusa

Question 7

localized skin lesion caused by E. rhusiopathiae

Answer 7

erysipeloid

— wound puncture into the skin; common among fish handlers, farmers, slaughterhouse workers, food preparation workers and veterinarians

Question 8

mode of transmission of Erysipelothrix rhusiopathae

Answer 8

zoonosis

Question 9

preferred sample from patients that have been infected with E. rhusiopathiae

Answer 9

skin biopsy with full thickness of the skin at the leading edge of of the discolored area

Question 10

virulence factors of E. rhusiopathiae

Answer 10

capsule
NEURAMINIDASE
HYALURONIDASE
surface proteins

Question 11

most common cause of bacterial vaginosis

Answer 11

Gardnerella vaginalis

Question 12

key tests for diagnosis of bacterial vaginosis

Answer 12

wet mount

gram stain

Question 13

the distinguishing characteristic found in the wet mount specimen of a petient that is infected with bacterial vaginosis

Answer 13

clue cells

– large squamous epithelial cells with numerous attached rods that are gram variable

Question 14

culture media that may cultivate Erysipelothrix spp and Gardnerella spp.

Answer 14

CAM
BAM
CNA (Colistin-Nalidixic acid Agar): BAM with colistin and nalidixic acid – help inhibit the growth of normal flora

Question 15

chemical/anticoagulant that inhibits the growth of Gardnerella spp.

Answer 15

SPS ( sodium polyethanol sulfanate)

– commercial blood culture media is not recommended for this organism

– should be cultivated in non-SPS media

Question 16

best medium for the isolation of Gardnerella vaginalis in female genital tract specimens

Answer 16

Human Blood Bilayer Tween Agar (HBT Agar)

• • CNA with Amphotericin B to prevent the growth of yeasts and filamentous fungi
• • blood enhanced the hemolytic activity of G. vaginalis

Question 17

incubation environement of Erysipelothrix spp and Gardnerella spp.

Answer 17

anaerobic conditions

5 to 10% CO2 within 48 hours

Question 18

organisms that ferment xylose

Answer 18

Gardnerella-like organisms

Question 19

the only gram positive, catalase negative bacilli that produces H2S precipitate (black) in TSI

Answer 19

E. rhusiopathiae