Prevention and prophylaxis of bacterial infections

Question 1

Define cleaning

Answer 1

Cleaning: Process in which substantial amounts of any material that is not part of an item (e.g. ‘soil’, dust) is removed

Question 2

Define disinfection

Answer 2

Disinfection: Any process in which the potential of an item to cause infection is removed by reducing the number of microorganisms present

Question 3

Define sterilisation

Answer 3

Process used to render an object free from all living organisms

Question 4

Does any disinfectant have ALL the desirable properties?

Answer 4

No

Question 5

What disinfectant is used far away from the patient to clean the environment

Answer 5

chlorine-based disinfectants

Question 6

Advantages of chlorine-based disinfectant?

Answer 6

Broad microbial activity, sporicidial, rapid, cheap

Question 7

Disadvantages of chlorine-disinfectants

Answer 7

Unstable, irritant and damage certain surfaces

Question 8

What disinfectant is used in kitchens and near-patient

Answer 8

Quaternary ammonium compounds (QACs)

Question 9

Advantages of QACs

Answer 9

Relatively safe, stable

Question 10

Disadvantages of QACs

Answer 10

Easily inactivated, restricted spectrum, no sporicidal activity, contamination

Question 11

What organism can grow and persist in QACs

Answer 11

P. aeruginosa

Question 12

What are some problems with disinfection

Answer 12

Re-contamination of surfaces can be rapid. Poor education/cost cuts can lead to cleaners spreading pathogens through the hospital.

Question 13

Washer disinfector process

Answer 13

Flush to removal soil
Wash including disinfectant
Rinse
Thermal disinfection 90C 1min
Equipment packaged and autoclaved

Question 14

4 alternatives to autoclaving (GEPI)

Answer 14

Glutaraldehyde
Ethylene oxide
Peracetic acid
Ionising radiation

Question 15

Function of ethylene oxide

Answer 15

Alkylation of protein/nucleic acid

Question 16

Function of glutaraldehyde

Answer 16

Crosslinking of macromolecules

Question 17

Function of peracetic acid

Answer 17

Oxidation

Question 18

Function of ionising radiation

Answer 18

ROS production

Question 19

How is infection prevented during surgery

Answer 19

Design of operation rooms: HEPA + +ve pressure
Antisepsis: Iodophor and chlorhexidine

Question 20

Iodophor: MOA

Answer 20

Inactivation of protein by binding to reactive groups like thiols

Question 21

Chlorhexidine: MOA

Answer 21

Disrupts membrane integrity, inserts into membrane

Question 22

Compare alcohol gel to handwashing with soap/water

Answer 22

• Require less time
• Can be placed in more accessible locations
• Don’t dry out hands, moisturisers can be contaminated.
• Are not sporicidal

Question 23

What surgeries require antibiotic prophylaxis

Answer 23

• Any where a patient is colonised by S. aureus.
• GI, respiratory, genitourinary tract surgeries: Contamination with commensal microbiota
• Repair of open wounds/fractures: Contamination with environmental organisms.
• Any involving fractured bones
• Any involving areas of acute inflammation or where there is pus.

Question 24

What is S. aureus decolonised with (antibiotic) and where is this carried out

Answer 24

Mupocirin; anterior nares

Question 25

PEP function

Answer 25

prevent disease in those exposed to pathogen

Question 26

PEP for rheumatic fever after strep infection

Answer 26

Penicillin G

Question 27

Those with a close contact to someone infected with bacterial meningitis or TB

Answer 27

Rifapicin for meningitis and isoniazid for those with TB

Question 28

Those bitten by animals or humans should be given PEP by giving what drugs?

Answer 28

Ampicillin-sulbactam (broad coverage), metronidazole (anaerobes)

Question 29

Can you give PEP to those at risk of endocarditis

Answer 29

YES

Question 30

What organisms can cause infection of burn wounds

Answer 30

* Staphylococci * Streptococci * Enterococci * Pseudomonas aeruginosa * Klebsiella spp. * Acinetobacter baumannii

Question 31

Main focus on preventing infection of burn wounds

Answer 31

Surgical debridgement and topical antisepsisi like Ag containing dressings

Question 32

What are passive immunisations

Answer 32

Antibody containing preparations