The types of organism and resistance which are tested for matters and can differ depending on the clinical scenario or source that the specimen was obtained from. When indiscriminate testing is performed, or testing for microorganisms or resistance that may not have clinical relevance, false positives may occur. This may result in confusion, and ultimately inappropriate antimicrobial prescribing. Therefore, it is essential that antimicrobial stewardship also focuses on the appropriate utilization of microbiology testing.