Staphylococcus

Question 1

What family is staphylococcus?

Answer 1

Micrococcaceae

Question 2

The three major pathogenic species of staphylococcus are ?

Answer 2

S.aureus, S.
epidermidis, and S. saprophyticus

Question 3

Staphylococcus are normal flora of?

Answer 3

Skin and nasopharynx

Question 4

Catalase positive test on gram positive cocci indicates?

Answer 4

Staphylococcus/micrococcus

Question 5

Catalase negative test on gram positive cocci indicates?

Answer 5

Streptococcus

Question 6

Voges-Proskauer (VP) positive test on staphylococcus/micrococcus indicates?

Answer 6

Staphylococcus

Question 7

Voges-Proskauer (VP) negative test on staphylococcus/micrococcus indicates?

Answer 7

Micrococcus

Question 8

Coagulase positive test on staphylococcus indicates?

Answer 8

Staphylococcus aureus

Question 9

Coagulase negative test on staphylococcus indicates?

Answer 9

Coagulase negative staphylococcus

Question 10

Novobiocin test is used to differentiate between

Answer 10

Coagulase negative staphylococcus. S. Epidermidis and S. Saprophyticus

Question 11

What binds the Fc portion of IgG and thus protects the organism against opsonisation & phagocytosis.

Answer 11

Protein A

Question 12

what leads to fibrin formation
around the bacterium and protects it from opsonization and phagocytosis?

Answer 12

Coagulase

Question 13

Haemolysins are Toxins that destroy ?

Answer 13

RBCs, Neutrophils, Macrophages & Platelets.

Question 14

Alpha toxin causes?

Answer 14

Critical necrosis

Question 15

Alpha toxin causes lysis of RBCs in?

Answer 15

Rabbit, sheep and cat

Question 16

Alpha toxin causes lysis of WBCs in?

Answer 16

Rabbit and humans

Question 17

Beta toxin causes lysis of RBCs in?

Answer 17

Sheep, human and Ox

Question 18

Gamma toxin acts?

Answer 18

Like delta toxin

Question 19

List the enzymes produced by staphylococci?

Answer 19

1. Coagulase.
2. Phosphatase.
   3.Dnase
3. Hyaluronidase.
4. Staphylokinase.
5. Lipase.
6. Gelatinase

Question 20

Delta toxin causes lysis of RBCs and WBCs in ?

Answer 20

All animals

Question 21

Which enzyme is unique to S.aureus

Answer 21

Coagulase

Question 22

Coagulase enzyme is unique to?

Answer 22

S.aureus

Question 23

How many types of enterotoxins exist?

Answer 23

5

Question 24

Enterotoxins are lettered ?

Answer 24

A to E

Question 25

Types A and D enterotoxins are associated with?

Answer 25

Food poisoning

Question 26

Enterotoxin type C and E are associated with?

Answer 26

Toxic shock syndrome

Question 27

Food poisoning is associated with which enterotoxins?

Answer 27

A and D

Question 28

Toxic shock syndrome is associated with which enterotoxins ?

Answer 28

C and E

Question 29

Exfoliatin is also called ?

Answer 29

epidemolytic or exfoliative toxin

Question 30

epidemolytic or exfoliative toxin is also called ?

Answer 30

Exfoliatin

Question 31

What is responsible for scalded skin syndrome?

Answer 31

Exfoliatin also called epidemolytic or exfoliative toxin A and B

Question 32

Exfoliatin, also called epidemolytic or exfoliative toxin A and B is responsible for ?

Answer 32

Scalded skin syndrome

Question 33

In Coagulase test, slide test is used for?

Answer 33

Bound Coagulase

Question 34

In Coagulase test, tube test is used for?

Answer 34

Bound and free Coagulase

Question 35

Diseases caused by direct organ invasion by S.aureus include?

Answer 35

1. Pneumonia. 2.Meningitis. 3. Osteomyelitis. 4. Acute bacterial endocarditis. 5. Septic arthritis. 6. Skin infections: (Abscesses,boils, carbuncles,furuncles, impetigo etc). 7. Bacteraemia/sepsis. 8. UTI by both S.aureus & S. saprophyticus

Question 36

Diseases caused by exotoxins include?

Answer 36

1. Gastroenteritis. 2. TSS-Toxic shock syndrome due to TSST-1(Tampon associated). 3. Scalded skin syndrome-SSS-by exfoliative toxin A & B

Question 37

What is the full meaning of MRSA?

Answer 37

Methicillin-Resistant staphylococcus aureus

Question 38

What is MRSA?

Answer 38

Most staphylococci are penicillin-resistant because they secrete penicillinase. Methicillin, Nafcillin, and other penicillinase-resistant penicillins are not broken down by penicillinase, thus enabling them to kill most strains of Staphylococcus aureus. MRSA is a strain of Staphylococcus aureus that has acquired multi-drug resistance, even against methicillin and nafcillin.

Question 39

What is VRSA?

Answer 39

Unfortunately, strains of Staphylococcus aureus resistant to vancomycin are now being reported. These VRSA isolates have acquired a chromosomal transposon DNA element called vanA from vancomycin resistant enterococcus (VRE) that encodes a series of proteins that modify the D-alanine-D-alanine terminus of the peptidoglycan cell wall, changing it to D-alanine-D-lactate, which has a low affinity for vancomycin.

Question 40

All strains of staphylococcus are notorious for ?

Answer 40

Hospital Acquired Infections Until recently, most strains of MRSA developed in the hospital under the influence of heavy antibiotic pressure. These strains had been classified as health care or hospital acquired MRSA or HA-MIRSA (this distinction is starting to go away). Generally these hospital acquired MRSA infections have exhibited extensive antibiotic resistance. In these cases vancomycin remains one of the most useful antibiotics.

Question 41

S. Aureus forms what color of colonies when cultures on sheep blood agar?

Answer 41

Gray to deep golden yellow colonies

Question 42

What is mannitol salt agar used for?

Answer 42

Mannitol salt agar or commercially available chromogenic media are used to screen for nasal carriers of S. aureus and to recover S. aureus from respiratory specimens of patients with cystic fibrosis.

Question 43

Staphylococcus epidermidis are associated with ?

Answer 43

Prostheses infection

Question 44

Staphylococcus saprophyticus are associated with?

Answer 44

UTI in sexually active women

Question 45

List the treatments for staphylococcus?

Answer 45

1. Penicillinase-resistant penicillins like Nafcillin,dicloxacillin. 2. Clindamycin. 3. Vancomycin. 4. Linezolid.

Question 46

How do we control staphylococcus?

Answer 46

By Strict personal & community hygiene