Search

Fusarium species are reported frequently as the most common causative agents of fungal keratitis in tropical countries such as India. Sixty-five fusaria isolated from patients were subjected to multilocus DNA sequencing to characterize the spectrum of the species associated with keratitis infections in India. Susceptibilities of these fusaria to ten antifungals were determined in vitro by the broth microdilution method. An impressive phylogenetic diversity of fusaria was reflected in susceptibilities differing at species level. Typing results revealed that the isolates were distributed among species in the species complexes (SCs) of F. solani (FSSC; n = 54), F. oxysporum (FOSC; n = 1), F. fujikuroi (FFSC; n = 3), and F. dimerum (FDSC; n = 7). Amphotericin B, voriconazole, and clotrimazole proved to be the most effective drugs, followed by econazole., (© The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The present study was carried out to investigate the antifungal effects of Cinnamomum zeylanicum, Citrus limon, Juniperus communis, Eucalyptus citriodora, Gaultheria procumbens, Melaleuca alternifolia, Origanum majorana, Salvia sclarea, and Thymus vulgaris essential oils against Fusarium species, the most common etiologic agents of filamentous fungal keratitis in South India. C. zeylanicum essential oil showed strong anti-Fusarium activity, whereas all the other tested essential oils proved to be less effective. The main component of C. zeylanicum essential oil, trans-cinnamaldehyde, was also tested and showed a similar effect as the oil. The in vitro interaction between trans-cinnamaldehyde and natamycin, the first-line therapeutic agent of Fusarium keratitis, was also investigated; an enhanced fungal growth inhibition was observed when these agents were applied in combination. Light and fluorescent microscopic observations revealed that C. zeylanicum essential oil/trans-cinnamaldehyde reduces the cellular metabolism and inhibits the conidia germination. Furthermore, necrotic events were significantly more frequent in the presence of these two compounds. According to our results, C. zeylanicum essential oil/trans-cinnamaldehyde provides a promising basis to develop a novel strategy for the treatment of Fusarium keratitis., (Georg Thieme Verlag KG Stuttgart · New York.)

Seventy Fusarium isolates derived from human keratomycosis were identified based on partial sequences of the β-tubulin (β-TUB) and translation elongation factor 1α (EF-1α) genes. Most of the isolates were confirmed as members of the F. solani species complex (75.71%), followed by the F. dimerum species complex (8.57%), the F. fujikuroi species complex (8.57%), the F. oxysporum species complex (4.29%) and the F. incarnatum-equiseti species complex (2.86%). A combined phylogenetic tree was estimated including all the 70 isolates. Isolates belonging to different species complexes formed separate clades. In this study, we also report the first isolation of F. napiforme from human keratomycosis. A new method based on a specific EcoRI restriction site in the EF-1α gene was developed for the rapid identification of F. solani. In vitro antifungal susceptibilities of the isolates to seven antifungals were determined by broth microdilution method. Terbinafine, natamycin and amphotericin B proved to be the most effective drugs, followed by voriconazole. The minimal inhibitory concentrations of clotrimazole, econazole and itraconazole were generally high (≥64 μg ml(-1) ). The interactions between the two most effective antifungals (natamycin and terbinafine) were determined by checkerboard microdilution method. Synergism (71.8%) or no interaction (28.2%) was revealed between the two compounds., (© 2013 Blackwell Verlag GmbH.)

A novel method is proposed for the accurate evaluation of in vitro antagonism. Based on the measurement of areas of the fungal colonies, biocontrol indices were calculated, which are characteristic to the antagonistic Trichoderma strains. These indices provide a useful tool to describe the biocontrol abilities of fungi.