Microbiology and Infection Control Flashcards
7 cards from real CER practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Microbiology and Infection Control flashcards as text
Which of the following best describes the mechanism by which glutaraldehyde achieves high-level disinfection?
Answer: Alkylates proteins and nucleic acids, cross-linking cellular components
Glutaraldehyde is an alkylating agent that cross-links proteins and nucleic acids within microbial cells, leading to irreversible cellular damage.
Standard precautions (formerly universal precautions) require treating blood and body fluids from ALL patients as if they are:
Answer: Potentially infectious regardless of diagnosis
Standard precautions apply to all patients regardless of known diagnosis, treating all blood and body fluids as potentially infectious.
What is the significance of a 'D-value' (decimal reduction time) in microbiology?
Answer: Time required to reduce a microbial population by 90% (1 log)
The D-value is the time required to reduce the number of viable microorganisms by 90% (one log10 reduction) under specified conditions.
Which component of the endoscope reprocessing environment presents the greatest ongoing biofilm contamination risk if not properly controlled?
Answer: Automated endoscope reprocessor (AER) interior
The interior chambers and tubing of AERs can harbor biofilm if not regularly cleaned, tested, and maintained, potentially recontaminating processed endoscopes.
A technician notices that the minimum effective concentration (MEC) test strip result is below the required threshold for the glutaraldehyde solution in use. What is the correct action?
Answer: Discard the solution and prepare a fresh batch
When MEC testing shows the disinfectant is below effective concentration, it must be discarded immediately and replaced with fresh solution — there is no approved remediation.
Transient flora on healthcare workers' hands differ from resident flora in that transient flora are:
Answer: Loosely attached and easily removed by proper hand washing
Transient flora are superficially attached microorganisms picked up through contact and are readily removed with soap and water or hand sanitizer, unlike deeper resident flora.
Which infection control principle is violated when a clean endoscope is placed on the same surface where a contaminated scope previously rested without decontamination of that surface?
Answer: Cross-contamination prevention
Placing a clean endoscope on an undecontaminated surface that held a dirty scope violates cross-contamination prevention principles by allowing indirect transfer of pathogens.