In AST terminology, what does QC stand for?

In AST terminology, what does QC stand for?

• A. Quick check
• B. Quarantine culture
• C. Quick culture
• D. Quality control

Answer: (D)

In antimicrobial susceptibility testing, QC stands for Quality control. It refers to the systematic checks that prove test results are accurate and reproducible. Practically, this means running standard, well-characterized control strains with every batch of tests to verify that media, reagents, and instruments are performing correctly and that the testing procedure is being followed properly. For example, in disk diffusion, a reference strain is inoculated and exposed to antibiotic discs, and the resulting inhibition zones must fall within established QC ranges. If they don’t, the batch is considered invalid and must be repeated or investigated. In broth methods like microdilution, control wells with known MICs ensure the antibiotic dilutions and inoculum are correct. Using recognized QC strains such as E. coli ATCC 25922, Staphylococcus aureus ATCC 25923 or 29213, and Pseudomonas aeruginosa ATCC 27853 helps confirm that the test conditions are appropriate. Quality control also covers confirming reagent lots, media quality, and instrument calibration. The aim is to ensure that the entire testing process produces trustworthy results. The other phrases would not capture this validation role; they describe speed or containment rather than the ongoing verification of test performance.

In antimicrobial susceptibility testing, QC stands for Quality control. It refers to the systematic checks that prove test results are accurate and reproducible. Practically, this means running standard, well-characterized control strains with every batch of tests to verify that media, reagents, and instruments are performing correctly and that the testing procedure is being followed properly.

For example, in disk diffusion, a reference strain is inoculated and exposed to antibiotic discs, and the resulting inhibition zones must fall within established QC ranges. If they don’t, the batch is considered invalid and must be repeated or investigated. In broth methods like microdilution, control wells with known MICs ensure the antibiotic dilutions and inoculum are correct. Using recognized QC strains such as E. coli ATCC 25922, Staphylococcus aureus ATCC 25923 or 29213, and Pseudomonas aeruginosa ATCC 27853 helps confirm that the test conditions are appropriate.

Quality control also covers confirming reagent lots, media quality, and instrument calibration. The aim is to ensure that the entire testing process produces trustworthy results. The other phrases would not capture this validation role; they describe speed or containment rather than the ongoing verification of test performance.