Post op complications

Question 1

What is a bio-film?

Answer 1

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Question 2

Factors for parthenogenesis of device associated infections?

Answer 2

Host, bacteria, device.

Question 3

Most common bacterial infection of skin devices?

Answer 3

Staph epidermidis - GPC 50-60%
Staph. Aures
E. coli - 30% 
- Non specific 
- Adhesion molecules

Question 4

Biofilm complications

Answer 4

Pharmokinetics - Bacteria are hard to access for AB’s.
Change in phenotype - Bacteria become more tolerant to AB’s, also proliferate slower making AB’s less effective.

Especially for very invasive prosthetic that are hard to reach (hip replacements) - need high doses of AB’s

Question 5

Management for DA infections.

Answer 5

If pus, drain and sample and culture blood. You can test the TIP of IV line for colonies (Tip - because outer IV line will have skin commensal bacteria).

After causative organism identified - IV antibiotics for 2 weeks as bacteria is in blood so have to clear whole infection out.

Question 6

Person’s most at risk of CD infection? Why?

Answer 6

2 points.

Question 7

What produce endospores?

Answer 7

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Question 8

How do survive?

Answer 8

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Question 9

What produce endospores?

Answer 9

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Question 10

How do endospores damage the colon

Answer 10

1. They (TOXIN A) bind to mucosal epithelial cells and are endocytosed.
2. pH of cell drops and endospore is activated.
3. G protein (RHO) which is responsible for the formation and maintenance of the actin cytoskeleton which maintains villi shape and connection to adjacent cells is deactivated by endospore.
4. Actin cytoskeleton is DE - polymerised
5. Rounded up epithelium allow for more toxins (TOXIN B) to pass through in to submucosa (and maybe blood. Also water can’t be absorbed so diarrhoea.
6. The inflamed submucosa is covered by debris which forms pseudo-membrane ulcers.

SUMMARY: COMBINED EFFECT OF TOXIN A AND TOXIN B

Question 11

Diagnoses for CDAD?

Answer 11

Cultures aren’t ideal as 20% of all patients have CD present in stool.

Instead conduct an antibody assay for toxins in stool. If CD is present but no toxin, can conduct PCR for toxin which is more sensitive.

Question 12

Treatment for CDAD?

Answer 12

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Question 13

Prevention of further CDAD?

Answer 13

Attention to hygiene and cleanliness

• Clean where patients have been (with sporicidial disenfectants)
• Improved hand hygiene

Limit use of predisposing antibiotics.

Question 14

Device factors that affect bacterial infection:

Answer 14

Device material
Device shape
Device surface
Source of material used for