BK - Hospital-Acquired Infection

Question 1

How quickly can hospital bacteria colonize a patient?

Answer 1

Within hours of admission, hospital strains of bacteria can establish colonies in a patient’s:

• Skin
• Respiratory tract
• Genitourinary tract

Question 2

What are the three main categories of risk factors for HAI?

Answer 2

1) Iatrogenic risk factors: Healthcare practices that can introduce pathogens or disrupt the body’s defenses. Examples include:

• Invasive procedures (catheters, intubation)
• Antibiotic use and prophylaxis

2) Organizational risk factors: Factors related to the hospital environment that can contribute to pathogen spread. Examples include:

• Contaminated air and water systems
• Staffing levels and facility layout (e.g., overcrowding)

3) Patient risk factors: Characteristics of the patient that make them more susceptible to infection. Examples include:

• Severity of illness
• Underlying immune deficiencies
• Length of hospital stay

Question 3

Why are surface cleaning procedures often ineffective?

Answer 3

Many surfaces in hospitals are not smooth and have imperfections that can harbor pathogens:

• Draw marks, scratches, etc.

Question 4

Why is terminal cleaning often ineffective in preventing HAIs? (2)

Answer 4

Terminal cleaning (cleaning after an infectious patient’s discharge) may not be sufficient to eradicate pathogens like MRSA due to:

• Spore formation in some bacteria (e.g., C. difficile)
• Difficulty in reaching all contaminated areas

Question 5

What is a superbug and name 3 examples?

Answer 5

A multidrug-resistant (MDR) bacterium highly resistant to antibiotics.

Examples of HAIs caused by superbugs:

• MRSA (Methicillin-resistant Staphylococcus aureus)
• VRE (Vancomycin-resistant Enterococcus)
• C. difficile (Clostridium difficile)

Question 6

What are MRSA resistant to?

Answer 6

Essentially resistant to all β–lactam antibiotics, due to the possession of the mecA gene encoding the low-affinity penicillin binding protein

Question 7

How does copper combat HAIs? (3)

Answer 7

Disrupting the bacterial cell wall: Copper can damage the cell wall of some bacteria.

Disrupting membrane potential (Gram-negative): Copper can interfere with the electrical balance across the cell membrane in Gram-negative bacteria.

Degrading DNA: Copper can rapidly degrade both genomic DNA and plasmid DNA in bacteria. This may:

• Prevent the development of mutational resistance.
• Reduce the spread of antibiotic resistance genes.
• Reduce the spread of genes for virulence and toxin production.