Antifungal potential of punicalagin against Cryptococcus neoformans species complex

This study evaluated the antifungal activity and cytotoxicity profile of the ellagitannin punicalagin, a compound extracted from the L. pacari A. St.-Hil (Lythraceae) leaf, against Cryptococcus neoformans species complex. Minimum inhibitory concentrations (MIC) were checked using the broth microdilution method. Minimum fungicidal concentrations (MFC) and time of death were used to confirm the antifungal activity of the compound. The in vitro cytotoxicity of punicalagin was tested in BALB/c3T3 fibroblasts and A549 human lung cancer cell line, while the hemolytic potential was tested on sheep erythrocytes. The morphological changes induced in yeast strains by the presence of punicalagin were also analyzed. Tested on eight isolates of the C. neoformans complex punicalagin showed MIC of 0.5 to 4.0 μg/mL and MFC> 256 μg/mL. Punicalagin also demonstrated a good growth inhibitory activity in time-kill curves, but it was not able to achieve a statistically significant reduction of fungal growth suggesting a fungistatic effect of the compound. In vitro cytotoxicity studies using the two cell lines showed that punicalagin has low activity on these cells and no activity on sheep erythrocytes. Morphological changes were seen in the yeasts strains studied when treated with punicalagin. Therefore, punicalagin is a potential antifungal for important pathogenic yeasts and presents a low cytotoxicity profile associated with no hemolytic effects.

Disseminated Cryptococcus deuterogattii (AFLP6/VGII) infection in an Arabian horse from Dubai, United Arab Emirates

BACKGROUND

During the past decades there has been an increase in cryptococcal infections caused by the basidiomycetous yeast species Cryptococcus gattii sensu lato, among humans and animals that live in endemic regions in Australia, Europe and the Americas. Unlike human cryptococcosis, little epidemiological data are available about C. gattii sensu lato infections in horses.

CASE REPORT

A fatal case of a disseminated C. gattii sensu lato infection in an 11-year-old Arabian gelding imported from South Africa into the United Arab Emitares is reported. Tissue samples were studied by conventional mycology procedures and the obtained cryptococcal isolate was molecularly characterized by mating-type determination, amplified fragment length polymorphism (AFLP) fingerprinting, and multi-locus sequence typing (MLST). Phylogenetic analysis was performed to investigate the geographic origin of the cryptococcal isolate. The isolate was identified as Cryptococcus deuterogattii (AFLP6/VGII), mating-type α. Phylogenetic analysis showed that it was closely related to another C. deuterogattii isolate from the Middle East.

CONCLUSIONS

A second case of a C. deuterogattii infection in the Middle East is described. It is likely that the horse acquired the infection in the Middle East, as the isolate is closely related to that of a recent human case from that region.