Staphylococci

Question 1

Give examples of Staphyloccoi species?

Answer 1

Staph. Aureus

Staph. Epidermidis

Staph. Saprophyticus

Question 2

What shape is Staphylococci and how are they arranged?

Answer 2

Cocci/ round shape and arranged in clusters = looks like grapes

Question 3

Gram stain? positive or negative?

Answer 3

Positive because of thick peptidoglycan in cell wall

Question 4

Outline 3 special characteristic of Staphylococci

Answer 4

> capsule (slime)

> no spores

> flagella

Question 5

What type of anaerobes are staphylococci and what does it mean?

Answer 5

Facultative anaerobes = can survive in aerobic and non-aerobic conditions

Question 6

What are the conditions for staphylococci growth? Temp and pH?

Answer 6

37 degrees

7.2-7.4 pH

Question 7

What culture medium is used for staphylococci?

Answer 7

Blood agar 5%

glucose broth

Question 8

Is staphylococci highly resistant or low resistant?

Answer 8

Highly resistant

Question 9

Outline non-toxigenic pathogenic factors of staphylococci ?

Answer 9

> coagulase and clumping factor
> protein A
> staphylokinase
> DNA-ase
> beta-lactamase
> urease
> catalase

Question 10

Outline the toxigenic pathogenic factors of staphylococci?

Answer 10

> hemolysins - a, b, g
> leucocydine
> enterotoxins
> exfoliatin
> toxin of staphylococcus shock syndrome

Question 11

How is staphylococci transmitted and how does it enter the body?

Answer 11

> via hands contact
aerosoles
blood
food

> enters through:

• mouth
• wounds
• vagina
• urethra
• skin and mucosa

Question 12

Outline non-toxin mediated diseases of staphylococci aureus?

Answer 12

Non-toxin mediated diseases can be local or systemic:
>soft tissue infections: pyoderma, folliculitis, furuncles, carbuncles, abscesses
>pneumonia, endocarditis, osteomyelitis, sepsis

Question 13

Outline toxin mediated diseases of staphylococci aureus?

Answer 13

These are toxigenic diseases:
>food poisoning
>toxic shock syndrome 
>toxic epidermal necrosis
>staphylococcal scaled skin syndrome

Question 14

What biological samples can be used for diagnosis of staphylococci aureus?

Answer 14

>pus
>nasal swabs
>blood culture 
>CSF
>urine 
>feces

Question 15

What type of direct method is used for Ag detection of staphylococci aureus?

Answer 15

> latex agglutination

> co- agglutination

Question 16

Staphylococcus epidermidis is a normal flora of skin and mucosa but can cause other infections? State the infections it can cause?

Answer 16

> endoplastitis (catheter associated infection)
endocarditis (infection of artificial valves)
Peritonitis (peritoneal dialysis infection)

Question 17

Staphylococcus Saprophyticus is a normal skin and mucosal flora but what other infection can it cause?

Answer 17

Cystitis in young women

Question 18

What antibiotic treatment can be used against staphylococci?

Answer 18

> beta lactamase inhibitor

>cloxacillin and cephalosporins

Question 19

Why are the antibiotic treatment with beta lactamase inhibitor and cloxacillin, cephalosporins ineffective with MRSA strains? How else can they be treated if with MRSA strain?

Answer 19

> because they produce beta lactamase with Mec-A gene

> MRSA infections treated with glycopeptides (vancomycin), linezolid and tigecycline