Antimicrobial Susceptibility - Fungal (Yeasts and Molds)

The following antifungal agents are tested (selective reporting by organism and body site):

Yeast (Candida species and yeast formerly known as Candida such as N. glabrata, etc.): Amphotericin B, anidulafungin, caspofungin, fluconazole, isavuconazole, itraconazole, micafungin, posaconazole, rezafungin, and voriconazole. 5-fluorocytosine and ketoconazole are tested by request only at an additional charge.

Yeast (non-Candida species): Amphotericin B, anidulafungin, caspofungin, fluconazole, 5-fluorocytosine, itraconazole, ketoconazole, micafungin, posaconazole, and voriconazole.

Mold: Amphotericin B, anidulafungin, caspofungin, isavuconazole, itraconazole, ketoconazole, micafungin, posaconazole, and voriconazole.

Requests for drug testing not performed at ARUP will be referred to the Fungus Testing Laboratory at the University of Texas Health Science Center at an additional charge.

Not all antifungal agents attain adequate concentration in all body sites:

*Vitreal Penetration: Systemic administration of echinocandins is not recommended for ocular infections because it has minimal tissue penetration. Consult ophthalmology, pharmacy, or infectious disease service for guidance.
*CSF Penetration: The echinocandins have suboptimal penetration in CSF and CNS tissues. Consult the pharmacy and/or infectious disease service for additional guidance.
*Urine Penetration: ONLY fluconazole and 5-fluorocytosine (note that the lack of detectable urine concentrations does not necessarily preclude use of other drugs when the infection involves the renal parenchyma). Lipid formulations of amphotericin B do not achieve adequate urine concentrations and should not be used to treat UTIs.

5-fluorocytosine: 5-FC should not be used as monotherapy for severe Candida infection because resistance can develop rapidly. It should be used rarely in neonates.

Susceptibility testing of some molds is not clinically relevant (i.e., Penicillium species or Cladosporium species).

Susceptibility testing for dermatophytes and dimorphic fungi is not performed at ARUP. If requested, isolates will be sent to the Fungus Testing Laboratory at the University of Texas Health Science Center. Specify agents to be tested on the susceptibility test requisition form.

Testing is not performed on isolates from environmental sources.

An additional processing fee will be billed for all organisms not submitted in pure culture, as indicated in the specimen requirements.

If species identification is not provided or if incorrect identification is provided, identification will be performed at ARUP. Additional charges apply.