Antimicrobial Susceptibility Testing

Map the pre-analytical, analytical, and post-analytical stages of an automated bacterial identification and susceptibility workflow.

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

Predict how inoculum density, medium, incubation, and timing errors can distort identification and susceptibility results.

Determine an MIC endpoint from a broth dilution growth pattern.

Interpret an MIC using current CLSI and EUCAST breakpoint tables, including the different meanings of their susceptibility categories.

Explain how MALDI-TOF identifies bacteria by generating and matching protein mass spectra.

Interpret MALDI-TOF identification scores, confidence indicators, and common causes of failed or misleading identification.

Trace the VITEK 2 workflow from inoculation of identification and AST cards to the final instrument output.

Trace the MicroScan WalkAway workflow from panel inoculation to identification and MIC reporting.

Trace the BD Phoenix workflow from panel inoculation to identification and susceptibility reporting.

Compare VITEK 2, MicroScan, BD Phoenix, and MALDI-TOF by analytical principle, turnaround time, workflow, strengths, and limitations.

Construct a routine QC plan using appropriate reference strains, testing frequency, and current CLSI or EUCAST acceptance ranges.

Determine whether an AST QC result is acceptable and select the immediate action required before patient results are released.

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

Explain how an automated expert system uses organism identity, MIC patterns, intrinsic resistance, and interpretive rules to flag or modify results.

Evaluate an expert-system alert without accepting or overriding it until purity, identification, QC status, and phenotype plausibility have been checked.

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 identification–AST concordance and intrinsic resistance patterns.

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

Perform and interpret the D-test for inducible clindamycin resistance.

Select appropriate phenotypic or molecular follow-up for suspected ESBL or carbapenemase production in Gram-negative bacteria.

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

Design a coherent 35-slide sequence that explains the automated identification–AST workflow within a 60-minute presentation.

Create audience-ready workflow diagrams and a comparison table for MALDI-TOF, VITEK 2, MicroScan, and BD Phoenix using authoritative citations.

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

Prepare timed speaker notes and concise answers to likely questions from master’s-level microbiology classmates.