Week 7 -> infections on a surface Flashcards Preview

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Flashcards in Week 7 -> infections on a surface Deck (28)
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1
Q

Name the mucosal membranes of the body

A

-Conjunctive, GI, resp, genitourinary

2
Q

Are mucosal layers sterile?

A

-They aspire to be but they have microbiota

3
Q

Name a virus which is skin microbiota

A
  • Papilloma virus

- Herpes virus

4
Q

Name some skin bacterial microbiota

A
  • S.aureus
  • Coag. neg staph
  • enterobacteriaciae eg coliforms such as e.coli, k.pneumoniae
5
Q

Name some fungi which are normal skin microbiota

A
  • yeats and dermatophytes
6
Q

Name some normal microbiota of the stomach

A
  • H.pylori
  • Strep
  • Staph
7
Q

Name some normal microbiota of intestines

A
  • Enterobacteriaciae
  • lactobacili
  • clostriudium
8
Q

Name some normal microbiota of the mouth

A
  • Viridans strep
  • Neisseriae
  • Candida
  • lactobacillus
9
Q

Name some normal microbiota of urethra

A

-Enterobacteiarcaie

10
Q

Name some normal microbiota of the vagina

A

-Lactobacilli

11
Q

Give an example of an infection which arises from invasion of a surface

A

-Pharyngitis by Strep pyogenes

12
Q

What are the mechanisms by which infections arise from a surface?

A
  • Invasion
  • Innoculation
  • Haemotogenous
  • Migration
13
Q

Give an example of an infection which arises from migration of a surface

A

-UTI bu e.coli

14
Q

Give an example of an infection which arises from innoculation of a surface

A

-Prosthetic joint surgery and coag neg staph

15
Q

Give an example of an infection which arises from haemotogenous spread of a surface

A

-Endocarditis and viridans strep

16
Q

What is the pathogenesis of endocarditis from viridans strep?

A
  • Viridans strep enters bloodstream (eg during dental work)
  • Subcutaneous tissue of heart contains finbronectin which has a receptors to which viridans strep can bind
  • Any break in the endotheluim exposes the receptor
17
Q

Name a surface infection caused by microbiota not at their usual site

A
  • Cellulitis
  • Pharyngitis
  • Gastroenteritis
18
Q

Describe some infections which can occur upon surfaces of medical equiptment

A
  • Intravascular lines can cause phlebitis
  • Catheters and UTIs
  • Prosthetic joints/valves and staph
  • Hickman lines
19
Q

What is the most likely infectious agent of endocarditis >1year post-op?

A

-Viridans

20
Q

What is the most likely infectious agent of endocarditis less than 1 year after op?

A

-Coag neg staph

21
Q

How does a bicuspid aortic valve predispose to endocarditis?

A

-Turbulent flow predisoises to eddys and damage to valves

22
Q

How does poor dental hygiene predispose to endocarditis

A

-Increased risk of innoculation

23
Q

How do pili/fimbrae increase the virulence of pathogens at a surface?

A

-Increase the chances of adherence

24
Q

How does biofilm formation increase the virulence of pathogens at a surface?

A

-Aids attachment and multiplication by producing a slime which evades the immune system and provides risitance to Abx

25
Q

What is quorum sensing?

A

-Communication between bacteria via signalling molecules which controls expression of virulence factors, sporulation and biofilm formation

26
Q

What is the pathway by which micro-organisms cause disease?

A

-Exposure -> adherence -> invasion -> multiplication -> dissemination

27
Q

How do you manage infections at a surface?

A
  • Diagnosis and identification of causative organism -> Abx
  • Blod cultures if appropriate
  • removal of prosthetic material or resection of infection
28
Q

What is microbiota?

A

-Microbes which reside on surfaces and in deep layers of the skin