ch 4 enterococci

Question 1

Enterococci Gram stain:

Answer 1

Gram +ve, cocci in chain

Question 2

Enterococci media and colony

Answer 2

Blood Agar : white non- haemolytic colonies.

Nutrient Agar :white colonies.
MacConkey Agar :small dark red colonies.

Question 3

is widely used to differentiate Enterococci and group D Streptococci, which are bile tolerant and can hydrolyze esculin to esculetin by esculinase. The esculetin reacts with the ferric citrate to produce black color.

Answer 3

Bile-Esculin Test

Question 4

Bile-Esculin Test
Substrate
End product
Enzyme

Answer 4

Enzyme: esculinase • Substrate: esculin • End product: hydrolysis of esculin to esculetin (black color)

Question 5

Enterococci can grow in______ Broth (Turbidity à there is growth). Non-Enterococci cannot grow in ____Broth (Clear à no growth).

Answer 5

6.5% NaCl

Question 6

Enterococci is heat-resistant bacteria
•

Answer 6

Can grow at 45ºC. • Can resist heating at 60ºC for 30 min

Question 7

is a component of the intestinal flora, that many
European countries use it as the standard indicator of fecal pollution,

Answer 7

Enterococcus faecalis

Question 8

Diseases caused by Enterococcus faecalis:

Answer 8

Urinary tract infection • Wound infection • Bacteremia

Question 9

Virulence factors of Enterococcus faecalis:

Answer 9

Adhesins
LTA
Hyaluronidase
• Gelatinase

Question 10

Treatment of E. faecalis

Answer 10

gentamicin with penicillin or ampicillin