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Objectives: Candida species are major causes of invasive mycoses in immunocompetent and immunocompromised hosts. Treatment options are limited in the setting of antifungal resistance and increased rates of echinocandin-resistant Candida glabrata have been reported. The novel arylamidine T-2307 demonstrates potent in vitro antifungal activity against Candida species. Our objective was to evaluate the in vitro and in vivo activity of T-2307 against resistant C. glabrata., Methods: In vitro activity was determined against 42 clinical C. glabrata isolates, including 17 echinocandin-resistant strains. Neutropenic ICR mice were inoculated intravenously with an echinocandin-resistant C. glabrata isolate (T-2307; caspofungin MICs ≤0.008 and 0.5 mg/L, respectively). Therapy with vehicle control, T-2307 (0.75, 1.5, 3 or 6 mg/kg subcutaneously once daily) or caspofungin (1 or 10 mg/kg intraperitoneally once daily) began 1 day post-challenge. Kidneys were collected on day 8 and fungal burden was assessed by counting cfu., Results: T-2307 demonstrated potent in vitro activity against C. glabrata (geometric mean MIC 0.0135 mg/L), which was maintained against echinocandin-resistant isolates (geometric mean MIC 0.0083 mg/L). T-2307 also demonstrated in vivo efficacy in mice infected with echinocandin-resistant C. glabrata. Significant reductions in fungal burden were observed at each dosage level of T-2307 compared with control. Reductions in fungal burden were also observed with high-dose caspofungin., Conclusions: T-2307 demonstrated potent in vitro activity against C. glabrata, including echinocandin-resistant isolates, which translated into in vivo efficacy against invasive candidiasis caused by an echinocandin-resistant C. glabrata strain. These results demonstrate the potential for T-2307 as therapy against echinocandin-resistant Candida., (© The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Objectives: AmBisome and micafungin were used alone and in combination in a series of studies designed to identify any additive or antagonistic effects of combination antifungal therapy., Methods: Immune-suppressed mice were infected either intravenously or intranasally with Aspergillus fumigatus. Micafungin, liposomal amphotericin B or both drugs together were administered for 7 days. Parameters of efficacy included survival and tissue burden of A. fumigatus., Results: Whilst each drug was effective in murine aspergillosis, additive effects were observed only in reduction of tissue burden in limited experimental conditions. No antagonism was seen., Conclusions: The present studies neither encourage nor discourage clinical use of combination therapy. Clinical trials are suggested before combined therapy is routinely adopted.

Outbred ICR mice were rendered neutropenic, infected intravenously with Fusarium solani and treated orally with voriconazole. When given alone, voriconazole was not protective up to 40 mg/kg/day. When grapefruit juice was administered before infection, mice were protected by voriconazole. The mechanism may be inhibition of gut mucosal cytochrome enzymes that rapidly degrade voriconazole in the mouse. These murine studies support expansion of voriconazole therapy in other highly resistant systemic mycoses.

Mycobacterium kansasii was administered intravenously to congenitally athymic (nude) mice. Beginning 1 week later, rifapentine, azithromycin, ethambutol or combined therapy was initiated orally. All three drugs were highly active individually. Although there was no evidence of antagonism, combined therapy was not more effective than either component used alone.