Sorted By Test Name - Mayo Medical Laboratories

MMLYP
81602
MMLRG
81601
Test Performed by: Focus Diagnostics, Inc.
5785 Corporate Ave.
Cypress, CA 90630-4750
Antimicrobial Susceptibility Panel, Yeast
Clinical Information: Candida species are the fourth leading cause of nosocomial infections and are
also frequent causes of community-acquired infections. Antifungal susceptibility testing may aid in the
management of patients with invasive infections due to Candida species or patients who appear to be
experiencing therapeutic failure. The Clinical Laboratory Standards Institute (CLSI) has approved the use
of a broth microdilution method for determining the susceptibility of Candida species.
Useful For: Determining in vitro quantitative antifungal susceptibility (minimum inhibitory
concentration) of non-fastidious yeast Testing may be warranted to aid in the management of certain
circumstances, such as: -Refractory oropharyngeal infections due to Candida species in patients who
appear to be experiencing therapeutic failure with standard agents at standard doses -Invasive infections
due to Candida species when the utility of azole antifungal agents is uncertain (eg, when the infection is
due to a non-Candida albicans organism)
Interpretation: The minimum inhibitory concentration (MIC) is recorded as the lowest concentration
of antifungal agent producing complete inhibition of growth. Interpretive breakpoints are available for
Candida species for fluconazole, itraconazole, and 5-flucytosine; the clinical relevance of testing any
other organism-drug combination remains uncertain. Agent MIC Ranges (mcg/mL) Interpretations
(mcg/mL) Susceptible Dose Dependent-Susceptible Intermediate Resistant Non-susceptible Amphotericin
0.12-8 < or =1 - - >1 - 5-Flucytosine 0.06-64 < or =4 - 8-16 > or =32 - Fluconazole 0.12-256 < or =8
16-32 - > or =64 - Itraconazole < or =0.125 0.25-0.5 > or =1 - Voriconazole 0.008-8 < or =1 2 - > or =4 -
Posaconazole 0.008-8 < or =1 2 - > or =4 - Caspofungin 0.008-8 < or =2 - - - >2 Micafungin 0.008-8 < or
=2 - - - >2 Anidulafungin 0.008-8 < or =2 - - - >2 - indicates not applicable 1. Voriconazole breakpoints
are used for posaconazole based on Pfaller MA, Messer SA, Boyken L, et al: Selection of a surrogate
agent (fluconazole or voriconazole) for initial susceptibility testing of posaconazole against Candida spp.:
results from a global antifungal surveillance program. J Clin MIcrobiol 2008;46:551-559 2. Proposed
breakpoints based on Pfaller MA, Diekema DJ, Ostrosky-Zeichner L, et al: Correlation of MIC with
outcome for Candida species tested against caspofungin, anidulafungin, and micafungin: analysis and
proposal for interpretive MIC breakpoints. J Clin Microbiol 2008;46:2620-2629 Please note that Candida
krusei is intrinsically resistant to fluconazole regardless of in vitro MIC result.
Reference Values:
Results reported in mcg/mL
Clinical References: Pappas PG, Rex JH, Sobel JD, et al: Guidelines for treatment of Candidiasis.
Clin Infect Dis 2004;38:161-189
Antimicrobial Susceptibility, Acid-Fast Bacilli, Rapidly Growing
Clinical Information: The rapidly growing species of mycobacteria (eg, Mycobacterium fortuitum,
Mycobacterium peregrinum, Mycobacterium chelonae, Mycobacterium abscessus, and Mycobacterium
mucogenicum) are seen with increasing frequency as causes of infection. Some examples of infections
caused by this group of mycobacteria are empyema, subcutaneous abscess, cutaneous ulcerative and
nodular lesions, peritonitis, endometriosis, bacteremia, keratitis, and urinary tract, prosthetic joint, wound,
and disseminated infections. Rapidly growing mycobacteria differ from other species of mycobacteria by
their growth rates, metabolic properties, and antimicrobial susceptibility profiles. Most species are
susceptible to some of the traditional antimycobacterial agents, but rapidly growing species may exhibit
resistance to certain antimycobacterial agents. In contrast, they often are susceptible to several of the
antibacterial agents used to treat common bacterial infections. Therefore, the antimicrobial susceptibility
profile of an organism within this group varies depending on the species. Isolates of Mycobacterium
fortuitum and Mycobacterium peregrinum generally exhibit susceptibility to amikacin, ciprofloxacin,
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