Candida Dubliniensis (Cd), a Species with an Extremely High Frequency of Paradoxical Effect (PE) with Caspofungin (CAS).

D. A. STEVENS1,2,3, M. J. MCCULLOUGH 4, K. V. CLEMONS 1,2,3, M. C. MARTINEZ 1;

Author address: 

1California Inst. for Med. Res., San Jose, CA, 2Santa Clara Vly. Med. Ctr., San Jose, CA, 3Stanford Univ., Stanford, CA, 4Sch. Dental Sci., Univ. Melbourne, Melbourne, Australia.

Abstract: 

Background: Paradoxical growth (at high concs., >MIC and MFC) with CAS has been described in Candida species. In the course of ongoing studies, we made a remarkable observation with Cd. Methods: MIC was determined by CLSI macrodilution and MFCs (> 96% killing) by previously published methods (Diag Micro Inf Dis 29:103), with the echinocandins CAS and micafungin (MICA). Typing of Cd was performed by PCR-based analysis of molecular co-dominant markers. Results: Though MICs and MFCs by standard endpoint were MIC some tubes, 0.05. Four Cd groups were defined by molecular typing; PE was noteworthy (p=0.007) in A (7/8) and B (7/7), less common in D (3/5) and not seen in least common subtype C (0/3). C vs. A or B pp>0.05. Though the former PE definition indicated >1 clear tube (and >96% killing) between the cessation of turbid growth at low concs. and resumption at higher, with 3 Cd there was increased growth and less killing at high concs., but no clear tube achieved until 12.5, with MFC 12.5-50 μg/mL. PE was not seen with MICA (MICs
2006

abstract No: 

M-1756

Full conference title: 

46th Interscience Conference on Antimicrobial Agents and Chemotherapy
    • ICAAC 46th