Objective: To evaluate and compare the in vitro antifungal properties of lufenuron and nikkomycin Z against isolates of Coccidioides immitis and Aspergillus fumigatus when used singly and in combination with the azole antifungal agent itraconazole.
Sample population: 3 clinical isolates of A fumigatus and the Silveira strain of C immitis.
Procedure: The fungal isolates were tested in vitro for susceptibility to the single and combination of compounds by use of microtiter-format susceptibility methods. Minimum inhibitory concentration end points were determined visually, and the contents of representative wells were examined microscopically for evidence of morphologic effects on fungi.
Results: No evidence of inhibition, either by susceptibility testing or direct microscopic examination of treated cells, was obtained with lufenuron under experimental conditions. In contrast, nikkomycin Z, a known inhibitor of fungal chitin synthesis, had potent activity against C immitis when used singly. A synergistic interaction between nikkomycin Z and itraconazole was found against isolates of both species tested.
Conclusions and clinical relevance: On the basis of our in vitro data, lufenuron does not appear to possess antifungal properties.