S7L1 - Infectious Surfaces

Question 1

What is a surface?

Answer 1

Interface between a solid and either a liquid or gas.

Question 2

What surfaces are present on patients?

Answer 2

Skin

• epithelium
• hair
• nails

Mucosal surfaces

• conjunctival
• gastrointestinal
• genitourinary

Question 3

Name some common skin microorganisms

Answer 3

Viruses - papilloma, herpes simplex

Bacteria (gram +ve) - Staphylococci aureus, coagulase negative staphylococcus.

Bacteria (gram -ve) - enterobacteriaceae

Fungi - yeasts, dermatophytes

Parasites - mites

Question 4

What are microbiota?

Answer 4

Can be called commensals.
Micro-organisms carried on skin and mucosal surfaces.
Normally harmless or even beneficial
Transfer to other sites can be harmful, leading to infections

Question 5

What 4 mechanisms describe how patients self infect?

Answer 5

Invasion
Migration
Inoculation
Haematogenous

Question 6

Describe some external natural surface infections?

Answer 6

Cellulitis 
Pharyngitis
Conjunctivitis
Gastroenteritis 
Urinary tract infection
Pneumonia

Question 7

Name some internal natural surface infections?

Answer 7

Endovascular ( endocarditis, vasculitis)
Septic arthritis
Osteomyelitis
Empyema

Question 8

Give some examples of prosthetic surface infections

Answer 8

Intravascular lines
Prosthetic joints
Cardia valves
Pacing wires
Endovascular grafts

Question 9

How do bacteria adhere to surfaces?

Answer 9

Thin strands of protein known as pili or fimbriae

Bind to host receptors on cell membrane