In Vitro Synergy Testing of Anidulafungin (ANID) with Itraconazole (ITR) and Voriconazole (VOR) against aspergillus spp. and Fusarium spp.

A. PHILIP, Z. ODABASI, J.R. RODRIGUEZ, V.L. PAETZNICK, E. CHEN, L. OSTROSKY-ZEICHNER, J.H. REX

Author address: 

Univ. of Texas-Houston Med. School, Houston, TX.

Abstract: 

Background: The lack of highly efficacious treatments for mould infections makes combination antifungal therapy potentially attractive. We evaluated the in vitro interaction of ANID with ITR and VOR against aspergillus spp. and Fusarium spp. Methods: Clinical isolates of aspergillus spp. (n=26) and Fusarium spp. (n=7) were tested against ANID in combination with ITR and VOR using the checkerboard method in RPMI-2% glucose media. Minimum inhibitory concentrations (MIC) and Fractional inhibitory concentration indices (FICI) were calculated at the optically clear (MIC-0) and prominent growth reduction endpoints (MIC-2) at 24 and 48 h. Results were interpreted as following: synergy (FICI £ 0.5), indifference (FICI > 0.5 and 4.0). Results: The mean FICI and ranges at 48 h are shown in the table. When assessed at MIC-2, 48 h, ANID combined with ITR or VOR was synergistic against 18 of 26 aspergillus spp. isolates and indifferent against all 7 isolates of Fusarium spp. Antagonism was rare. Species (n) ANID+ITR ANID+VOR ANID+ITR ANID+VOR mean FICI (range) mean FICI (range) mean FICI (range) mean FICI (range) at MIC-0 at MIC-0 at MIC-2 at MIC-2 A. flavus (8) 0.82 (0.50-1.00) 1.00 (1.00-1.02) 0.42 (0.25-0.50) 0.57 (0.50-1.00) A. fumigatus (8) 0.75 (0.50-1.00) 0.56 (0.50-1.00) 0.47 (0.27-0.52) 0.37 (0.26-0.51) A. niger (6) 0.92 (0.51-1.00) 0.92 (0.50-1.01) 2.23 (0.49-4.42) 1.95 (0.48-2.48) A. terreus (4) 0.629 (0.50-1.00) 0.88 (0.53-1.00) 1.46 (0.49-2.50) 1.30 (0.37-2.24) F. oxysporum (2) 2.00 (2.00-2.00) 2.00 (2.00-2.00) 2.00 (2.00-2.00) 1.00 (1.00-1.00) F. solani (5) 1.81 (1.06-2.00) 2.00 (2.00-2.00) 2.00 (2.00-2.00) 2.00 (1.00-3.00) Conclusion: ANID combined with ITR and VOR was most often synergistic against aspergillus spp. in vitro. In vivo evaluation of these combinations is warranted.
2003

abstract No: 

M-988

Full conference title: 

43rd Interscience Conference on Antimicrobial Agents
    • ICAAC 43rd