Organisms that are either present in very low numbers, or that possess a characteristically slow growth rate, may require an extended incubation before they are detected in culture. Amplification and/or detection of unique sequences of either DNA or RNA provide for more timely identification. This is true whether they are applied to the specimen for direct detection, or in some cases, to culture-positive specimens for culture confirmation (identification).
Even for organisms that are easy to recover and identify (eg., Staphylococcus aureus) various molecular methods offer the ability for either direct detection in clinical material, or more rapid identification that would greatly aid in treatment and clinical management decisions.
NOTE: Culture may still be required in order to obtain an antibiotic susceptibility test report.
