Chain of Infection: S. Aureus

Question 1

What are the links in the chain of infection?

Answer 1

• Infectious agent
• Reservoir
• Portal of exit
• Mode of transmission
• Portal of entry
• Susceptible host

Question 2

What type of microorganism is S. Aureus?

Answer 2

Gram positive coccus

Question 3

What is the virulence factor of S. Aureus?

Answer 3

Panton Valentine Leucocidin (PVL)

Question 4

How can antimicrobial susceptibility come into play when treating S. Aureus infections?

Answer 4

1. Flucloxacillin sensitive (MSSA) –> treat with flucloxacillin
2. Flucloxacillin resistant (MRSA) –> treat with Vancomycin

Question 5

Give examples of oral infections with Staphylococci:

Answer 5

• Angular cheilitis (63%)
• Staphylococcal mucositis
• Parotitis
• Endodontic & implant infections
• Osteomyelitis

Question 6

Give examples of exogenous sources of S. aureus (MRSA)?

Answer 6

• Air/water syringe
• Dental chair
• Dental impression gun

Question 7

Give examples of common portals of exit of S. Aureus:

Answer 7

• hands
• aerosols from handpieces