Microbiology

Question 1

Describe the appearance of staphylococcus sp.

Answer 1

Gram positive cocci in clusters

Question 2

What are the two main types of staphylococcus infections

Answer 2

Staph aureus (coagulase positive)
Coagulase negative staph (epidermidis, saprophyticus)

Question 3

What colour does staph aureus appear in blood agar

Answer 3

golden

Question 4

Describe the appearance of a positive test result for a coagulase positive organism

Answer 4

Lump forming at the bottom of the test tube - the plasma has clotted

Question 5

Describe the appearance of gram positive streptococci

Answer 5

Chains rather than clusters

Question 6

What antibiotic is used to treat staph aureus

Answer 6

flucloxacillin

Question 7

What is different about staph aureus to all other staph species

Answer 7

produces enzymes such as coagulase (clots plasma)

Question 8

How might staph epidermis cause infection

Answer 8

When it is associated with an implanted artificial material such as joints or heart valves or Catheters

Question 9

What organism causes urinary tract infection in women of child-bearing age

Answer 9

Staph saprophyticus

Question 10

Strep species are anaerobic. True or false

Answer 10

False - they are aerobic

Question 11

How are streps classified

Answer 11

By haemolysis on blood agar

Question 12

What are the 3 types of haemolysis

Answer 12

beta - complete haemolysis
alpha - partial haemolysis
gamma - no haemolysis

Question 13

what are the 2 categories of beta haemolytic streptococci

Answer 13

group A (throat, severe sin infections)
group B (meningitis in neonates)

Question 14

what are the 2 categories of alpha haemolytic strep

Answer 14

pneumoniae

viridans (commensals of mouth, throat, vagina)

Question 15

where do none haemolytic strep cause infection

Answer 15

bowel

UTI

Question 16

Give 5 ways that the skin acts as a defence against infection

Answer 16

Intact 
Dry surface 
sebum (inhibits bacterial growth)
competitive bacterial flora
concept of resident and transient flora

Question 17

Is Impetigo highly infection

Answer 17

Yes - kids need to be kept off school because of it

Question 18

What happens in Staphylococcal scalded skin syndrome

Answer 18

The baby has lost vast areas of the surface of the skin. The wounds become weepy and therefore the baby will become dehydrated. They are treated aggressively with antibiotics and often need IV fluids

Question 19

What diseases can Group A strep cause

Answer 19

Infected eczema
Impetigo
Cellulitis
Erysipelas
Necrotising fasciitis

Question 20

What is the treatment of choice for group A strep

Answer 20

penicillin

Question 21

What is the treatment of necrotising fasciitis

Answer 21

Immediate surgical debridement as well as antibiotics

This is a life threatening condition

Question 22

What are the presenting complaints of necrotising fasciitis

Answer 22

Extreme pain

Not much to see on the skin surface

Question 23

When is it appropriate to take swabs from a leg ulcer

Answer 23

Signs of cellulitis or infection are present

Question 24

What does tinea mean?

Answer 24

ringworm

Question 25

What is Tinea pedis more commonly known as

Answer 25

Athlete's foot

Question 26

How does the body acquire a fungal infection

Answer 26

through soggy skin

Question 27

Where do fungal infections attack and infect

Answer 27

Keratinised tissues only (skin, hair and nails)

Question 28

How do fungal infections have a ring appearanec

Answer 28

The lesion grows outward and heals in the centre

Question 29

How are fungal infections (dermatophyte infections) diagnosed?

Answer 29

clinical appearance Woods light skin scrapings, nail clippings, hair

Question 30

How are dermatophyte infections treated

Answer 30

Clotrimazole cream or similar | Topical nail paint (amorolfine)

Question 31

Where does candida cause an infection

Answer 31

``` In skin folds where the area is warm and moist Under the breasts groin areas abdominal skin folds nappy area in babies ```

Question 32

What is the causative organism of scabies

Answer 32

Sarcoptes scabiei

Question 33

What is Norwegian Scabies

Answer 33

Chronic crusted form of Sarcoptes scabiei which is highly infection

Question 34

What is the treatment of scabies

Answer 34

Malathion lotion - applied overnight to the whole body and washed off the next day

Question 35

What is the treatment for lice

Answer 35

Malathion

Question 36

What 3 different types of patients require single room isolation

Answer 36

Patients with Group A strep infection Patients with methicillin resistant Staph aureus (MRSA) Patients with Scabies