Antimicrobial Susceptibility Testing

Assess culture purity and select appropriate isolated colonies for automated identification and AST.

Predict how inoculum density, colony age, medium, preparation delays, incubation conditions, and timing errors can distort identification or susceptibility results.

Determine an MIC endpoint from a broth microdilution growth pattern, including trailing or otherwise ambiguous growth.

Classify an MIC using current organism–drug–method-specific CLSI and EUCAST tables, documenting the standard version and distinguishing their susceptibility category definitions.

Interpret a MALDI-TOF identification result by relating spectrum generation and database matching to confidence indicators and common causes of failed or misleading identification.

Trace the VITEK 2 workflow from suspension and card selection through kinetic optical readings to identification confidence and reported MIC results.

Trace the MicroScan WalkAway workflow from panel selection and inoculation through automated reading, identification, and broth microdilution MIC reporting.

Trace the BD Phoenix workflow from panel preparation and inoculation through growth detection, identification, and susceptibility reporting.

Evaluate automated AST performance using essential agreement, categorical agreement, minor error, major error, and very major error.

Construct a comparison that distinguishes the identification-only role of MALDI-TOF from the ID–AST capabilities of VITEK 2, MicroScan, and BD Phoenix, considering principles, turnaround time, workflow, strengths, and limitations.

Design a version-controlled QC plan for MALDI-TOF and automated ID–AST systems using appropriate calibrants or reference organisms, AST control strains, testing frequencies, acceptance criteria, and current manufacturer and CLSI or EUCAST instructions.

Apply current acceptance rules to QC results and decide whether to accept the run, repeat testing, investigate the system, or hold patient results.

Troubleshoot an out-of-range QC result by systematically evaluating inoculum, organism, reagents, storage, environment, and instrument factors.

Evaluate an automated expert-system alert by relating organism identity and MIC patterns to intrinsic resistance and interpretive rules, then decide whether the result should be accepted, suppressed, overridden, repeated, or confirmed.

Verify the accurate transfer of organism identification, MICs, categories, comments, suppressed drugs, and critical alerts from an analyzer to the LIS.

Construct a clinically appropriate final report using selective or cascade reporting, interpretive comments, and urgent-notification rules.

Distinguish a likely technical error from a plausible unusual resistance phenotype by checking culture purity, identification–AST concordance, intrinsic resistance, QC status, and expected phenotype patterns.

Select confirmatory methods for flagged Gram-positive resistance phenotypes such as methicillin resistance in staphylococci and vancomycin resistance in enterococci.

Interpret a D-test result by applying correct disk placement, incubation, and D-zone criteria.

Select phenotypic or molecular follow-up for suspected ESBL or carbapenemase production in Gram-negative bacteria according to the purpose of testing and current laboratory policy.

Explain why automated colistin results may be unreliable and when broth microdilution confirmation is required.

Create a 35-slide storyboard that allocates content and speaking time across the pre-analytical workflow, MIC interpretation, platforms, QC, reporting, limitations, and troubleshooting.

Synthesize MALDI-TOF, VITEK 2, MicroScan, and BD Phoenix characteristics into an accurate slide-ready comparison table supported by authoritative, current citations.

Develop a case-based slide sequence showing how QC failure, mixed culture, or an unusual phenotype is investigated before LIS reporting.

Deliver a timed rehearsal, revise the slides and speaker notes to fit 60 minutes, and prepare concise answers to likely master’s-level questions.