Antimicrobial stewardship is usually taught as a hospital program. This article teaches the part students actually need: how the microbiology laboratory drives stewardship through...
How the lab detects an AmpC beta-lactamase: the cefoxitin screen, the cloxacillin and boronic acid confirmatory tests, chromosomal versus plasmid-mediated AmpC, and the inhibitor l...
How antimicrobial susceptibility testing works, when to use disk diffusion vs. dilution vs. gradient vs. automated methods, how CLSI and EUCAST breakpoints turn a measurement into...
How the lab detects an extended-spectrum beta-lactamase: the screening cutoffs, the CLSI combined-disk confirmatory test and its ≥5 mm rule, the control strains, and why a co-produ...
How a McFarland densitometer works: its parts, photometric principle, operation, and calibration. It reads bacterial suspension turbidity directly in McFarland units for susceptibi...
How the Ambler molecular classes (A through D) and Bush-Jacoby functional groups describe the same enzymes from two different angles, with the mapping most articles skip.
Phenotypic Methods for the Detection of Carbapenemases
Carba NP Test (CNPt): Principle, Procedure, Results
MIC stops bacterial growth; MBC kills it. Learn how MBC is determined from MIC tubes, the MBC/MIC ratio, and the specific clinical scenarios (endocarditis, osteomyelitis, neutropen...
How McFarland turbidity standards are prepared, why the 0.5 standard (1.5 x 10^8 CFU/mL) is the target for antimicrobial susceptibility testing, and how a wrong inoculum density gi...
E-test gives an exact MIC value, not just a Susceptible/Resistant call. Full procedure, strip placement, and the reading rules that trip up most students — plus how E-test strips a...
MHT detects carbapenemase via a clover-leaf growth pattern, and CLSI dropped it from its guidelines in 2018 in favor of mCIM and Carba NP. The procedure, the limitations that led t...
Stokes disc diffusion runs a susceptible control strain on the same plate as the test isolate, so weak discs or off media distort both zones equally and the comparison still holds.
Step-by-step broth macrodilution and microdilution procedure for MIC determination: antibiotic stock prep, 0.5 McFarland standardization, reading results, and a troubleshooting gui...
The full modified Kirby-Bauer procedure — inoculum prep, disc placement, and the three exceptions to standard zone reading that catch most students off guard, including the β-lacta...
