Virulence factors and determination of antifungal susceptibilities of Candida species isolated from palm wine and sorghum beer

Abstract

Since it has been considered that Candida species in food or drinks may, following ingestion, enter the bloodstream and cause fungaemia, the presence of these yeast species in traditional alcoholic beverages may be of some clinical significance. Thus we attempted to assess virulence factors and antifungal susceptibility profile of Candida strains and other potential pathogenic yeasts isolated from palm wine and sorghum beer (tchapalo). Of the 23 yeast isolates from palm wine, phospholipase, esterase and haemolysin production was revealed amongst 69.6%, 65.2% and 100% isolates respectively with high activity belonging to Candida tropicalis strains. All the isolates were biofilm producers at variable degree but none showed proteinase activity. When the isolates were tested for their susceptibility to five antifungal agents, we found that ketoconazole (91.3%) followed by fluconazole (78.3%) and amphotericin B (73.9%) were the most potent agents. Of the 14 isolates from tchapalo, 57.1%, 87.5% and 57.1% exhibited phospholipase, haemolysin and esterase activity respectively. They did not also show proteinase activity while 87.5% produced biofilm. The majority of the isolates were susceptible to azoles (92.7%) and amphotericin B (85.3%) but they were 5-flucytosine resistant like palm wine strains.