Staphylococcus

Question 1

Staphylococcus is gram negative or positive?

Answer 1

Positive

Question 2

it is the second most common cause of urinary tract infection (after E. coli).

Answer 2

STAPHYLOCOCCUS SAPROPHYTICUS

Question 3

What causes infection is sometimes known as “honeymoon cystitis”.

Answer 3

STAPHYLOCOCCUS SAPROPHYTICUS

Question 4

STAPHYLOCOCCUS SAPROPHYTICUS?

Answer 4

This organism is a Gram-positive, coagulase-negative bacterium and a significant cause of urinary tract infections,

Question 5

STAPHYLOCOCCUS EPIDERMIDIS identification

Answer 5

Identification •
Staphylococcus epidermidis is non-hemolytic on growth on sheep blood agar • • •
Does not ferment mannitol Is non-pigmented
Is coagulase-negative.

Question 6

S. Aureus

Identification

Answer 6

Identification •
S. aureus is beta-hemolytic on sheep blood agarا.م.د. حسن محمود موسى ابو المعالي
•
•
•
•
Ferments mannitol
Is often golden pigmented (hence the name aureus) Is coagulase-positive Presence of protein A

Question 7

S. Aureus

Identification

Answer 7

Identification •
S. aureus is beta-hemolytic on sheep blood agarا.م.د. حسن محمود موسى ابو المعالي
•
•
•
•
Ferments mannitol
Is often golden pigmented (hence the name aureus) Is coagulase-positive Presence of protein A

Question 8

MRSA

Answer 8

Methicillin-resistant Staphylococcus aureus (MRSA) is defined as any strain of Staphylococcus aureus that has developed resistance to beta-lactam antibiotics (such as penicillins) and cephalosporins. This results from the production of a phage-coded penicillinase that degrades beta lactam antibiotics. Some strains also have modified penicillin binding proteins.

Question 9

GROUP A STREPTOCOCCUS (S. PYOGENES) Diagnosis?

Answer 9

Laboratory diagnosis

1. Direct detection - the antigen is extracted from a throat swab. The antigen extract will then bind with antibody specific to the group A streptococcal carbohydrate. This has classically involved agglutination of antibody coated beads.
2. Lancefield grouping of isolated beta hemolytic colonie. 3. Colonies are beta hemolytic and their growth is inhibited by bacitracin (presumptive diagnosis).
3. Patient serum shows antibodies to streptolysin O or other streptococcal antigens. This is important if delayed clinical sequelae occur.

Question 10

T-S-S ?

Answer 10

A toxic shock-like disease (including rash, fever and shifting of fluid from the
bloodstream to peripheral tissues with resulting edema). This causes blood pressure to drop rapidly and organs (e.g., kidney, liver, lungs) to fail.

Question 11

T-S-S ?

Answer 11

A toxic shock-like disease (including rash, fever and shifting of fluid from the
bloodstream to peripheral tissues with resulting edema). This causes blood pressure to drop rapidly and organs (e.g., kidney, liver, lungs) to fail.

Question 12

Flesh eating bacteria?

Answer 12

necrotizing myositis and fasciitis. Necrotizing fasciitis (which has earned
Group A Streptococci the name “the flesh-eating bacteria”) rapidly destroys muscles, fat, and skin tissue.

Question 13

Scarlett fever caused by?

Answer 13

Group A Streptococcus pyogenes

Question 14

Scarlett fever symptoms

Answer 14

Scarlet fever usually begins with a fever and sore throat which may be accompanied by: •
chills • • vomiting abdominal pain
#the tongue may have a whitish coating and appear swollen. It may also have a “strawberry”-like (red and bumpy) appearance •
• the throat and tonsils may be very red and sore leading to pain in swallowing

Question 15

Rheumatic fever

Answer 15

Rheumatic fever is an inflammatory disease affecting primarily the heart and joints.

Question 16

Rheumatic fever caused by streptococcus group A

Answer 16

M protein cross-reacts with heart myosin leading to autoimmunity.