Effects of galanin message-associated peptide and neuropeptide Y against various non-albicans Candida strains

Antimicrobial peptides (AMPs) could represent promising therapeutic agents against fungal pathogens, especially in cases of pathogen resistance to common antifungal substances. The neuropeptides galanin message-associated peptide (GMAP) and neuropeptide Y (NPY) are both potent AMPs against certain microbes. The objective of this study was to test clinically relevant non-albicans Candida strains (C. glabrata, C. krusei, C. lusitaniae, C. parapsilosis, C. pelliculosa, C. tropicalis and C. utilis) with regard to their susceptibilities to NPY and GMAP. GMAP showed a higher potency than NPY, which only inhibited growth of some isolates of C. krusei, C. tropicalis and C. utilis. Interestingly, the fluconazole-resistant C. krusei was susceptible to both AMPs. In summary, we show that these neuropeptides have Candida strain-dependent antifungal activity, which in some cases does not match the susceptibility of the strains to the positive controls fluconazole and magainin I. Thus, the findings demonstrate the therapeutic potential of these AMPs in cases of resistance to traditional antifungal substances. This study also confirms the research on neuropeptides as potential fungicides, which are still in the early stages. The results also suggest that testing of strain-specific susceptibility is mandatory. (C) 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.