Microbiology - chapter 5 - Staphylococci

Question 0

Coagulase positive Staphylococci?

Answer 0

Staphylococcus Aureus

Question 1

Staphylococci live in the nasopharynx and skin of up to 50% of people. What are the 3 major pathogenic species of Staphs?

Answer 1

1 Staphylococcus Aureus
2 Staphylococcus epidermidis
3 Staphylococcus saprophyticus

Question 2

Staphylococci have these 6 proteins that disable our immune system..?

Answer 2

1 Protein A - protect the bug from phagocytes by binding to Fc on IgG
2 Coagulase - lead to fibrin formation around the bacteria
3 hemolysins - destroy RBCs, leukocytes, platelets & macrophages
4 Leukocidins - called Panton-Valentine Leukocidin, destroy WBC
5 Pennicilinase
6 Novel Penicillin binding protein

Question 3

Staph Aureus have four proteins used to tunnel through tissues. Which?

Answer 3

1 Hyaluronidase - breaks down proteoglycans in connective tissue
2 Staphylokinase - lyses fibrin clots
3 Lipase
4 protease

Question 4

Staphylococcus Aureus exotoxins?

Answer 4

1 Exfoliatin - causes skin to slough off
2 Enterotoxins - cause food poisoning
3 Toxic Shock Syndrome toxin - toxin-MHC II complex activate T cells

Question 5

See if you can list 8 diseases resulting from Staphylococcus aureus invading organ systems directly?

Answer 5

1 Pneumonia
2 Meningitis
3 Osteomyelitis
4 Acute bacterial endocarditis
5 Septic arthritis
6 Skin infections
7 Bacteremia/sepsis
8 Urinary tract infections

Question 6

What is the name of the toxin made Staphylococcus aureus that causes Scalded skin syndrome, and where does it act?

Answer 6

Exfoliative toxin A and B cleaves the middle of epidermis

Question 7

Swollen tissue over bone with shakes and systemic fever?

Answer 7

Osteomyelitis

Question 8

IV drug users are proned to develop these complications related to staph infections …. ?

Answer 8

tricuspid valve endocarditis and subsequent pneumonia caused by embolization of the infected valve.

Question 9

Most common cause of septic arthritis in pediatric age group and adults over 50 yrs?

Answer 9

Staphylococcus ureus

Question 10

Penicillin binding protein 2A is associated with?

Answer 10

resistance to antibiotics

Question 11

Community aquired-MRSA and Panton-Valentine Leukocidin toxin are linked in what way?

Answer 11

CA-MRSA carry genes coding for PVL toxin which is associated with the ability to form skin abscesses. By this way, the CA-MRSA can form abscesses on their host, which in turn becomes a smart route for the little basterds to spread. Clever ey?

Question 12

Most frequent staphylococci to propagate on prosthetic devices?

Answer 12

Staphylococcus epidermidis

Question 13

Second leading cause of urinary tract infections?

Answer 13

Staphylococcus saprophytcus(second only to Escheria Coli)

Question 14

Staphylococcus epidermidis is coagulase ……………………. ?

Answer 14

negative

Question 15

What is a furuncle?

Answer 15

Small abscess that penetrate deep into the subcutaneous tissue

Question 16

When does a furuncle become a carbuncle?

Answer 16

When furuncles communicate under the skin, becoming multiple contigous painful lesions, they are called carbuncles.

Silly names