Gram Negatives Flashcards

1
Q

describe the structure of a Gm -ve cell wall

A

Inner and outer membrane
thin layer of peptidoglycan between
Lipopolysaccharides facing external environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which of the classes in the 4C antibiotics is used to treat legionella pneumonia?

A

Quinolones ( Ciprofloxacin in the 4Cs )

Tx:
Levofloxacin and Co-amoxiclav

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What monobactam is used in NHS Tayside?

A

Aztreonam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Aztreonam only treats Gm -ves. TRUE/FALSE?

A

TRUE

does not offer any Gm +ve or anaerobe cover

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Aztreonam is an alternative to Gentamicin in what group of patients?

A

Renal impairment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why should Gentamicin not be given to patients with Myasthenia Gravis?

A
  • Impairs neuromuscular transmission

- Causes muscle weakness and therefore resp. depression in these patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What groups of antibiotics may offer Gm -ve cover?

A
  • Beta lactams ( and monobactam )
  • Aminoglycosides
  • Macrolides
  • Tetracyclines
  • Chloramphenicol
  • Co-trimoxazole
  • polymixins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Are most Gm -ve infections cocci or bacilli shaped?

A

Bacilli

only true coccus is Neisseria Veillonella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What factors should be considered when pneumonia is suspected?

A
Hospital or community acquired?
Ventilated not ventilated?
Time of year/ season 
Immunosuppressed?
Pre-existing chronic lung disease 
Epidemiological exposures (e.g. PWID, vaccine status) Travel ( e.g. for resistant gram negs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the Gram stain and shape of haemophilus influenzae

A

Gm -ve coccobacillus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What agar is required for growth of haemophilus influenzae?

A

Chocolate agar media

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What antibiotics are active against haemophilus influenzae in the UK?

A

Amoxicillin

Doxycycline also active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is meant by “atypical” pneumonia?

A

Any infection causing pneumonia which is NOT strep. pneumoniae

e.g. Mycoplasma /Coxiella burnetii / Legionella pneumophila

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What treatment is commonly used for “atypical pneumonia”?

A
  • Doxycycline (not very effective against Legionella though)
  • Clarithromycin
  • Levofloxacin in penicillin allergic severe pneumonia and for Legionella NOTE Cdiff risk
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where is Legionella commononly found in the environment?

A

Lukewarm aerosolised water ( showers, air conditioning, taps, hot tubs )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Who is more at risk of legionella infection?

A
  • smokers
  • males
  • COPD
  • Immunosuppressed
  • Malignancy
  • Diabetes
  • dialysis
17
Q

What serogroup of Legionella is responsible for most disease?

A

Serogroup 1

18
Q

What bacteria are most important with regards to Gm -ve sepsis?

A

E-coli
Pseudomonas
Neisseria meningitidis
these 3 = most important

Other causes:
Klebsiella
Serratia
Acinetobacter
Enterobacter 
Citrobacter
19
Q

What colour change is observed on MacConkey Agar with sorbitol for Ecoli0157?

A

changes to bright pink

20
Q

Coliforms covers what types of bacteria?

A
E-coli
Klebsiella sp
Proteus sp.
Enterobacter sp.
Serratia sp.
21
Q

Give examples of antibiotics which contain another ingredient to breakdown beta-lactamase and attempt to prevent antibiotic resistance

A

Co amoxiclav (clavulanic acid)

Tazocin (Tazobactam agent)

22
Q

Extended spectrum beta lactamase organisms rule out what antibiotics?

A

Penicillins, cephalosporins and aztreonam

23
Q

What should be remembered when prescribing for obese and pregnant patients?

A

They may require extra antibiotic coverage for distribution

Some guidelines are based on a 70kg man (which is not the case in todays society)

24
Q

Why is trimethoprim NOT used in sepsis?

A

It is bacteriostatic