Antifungal Potential of Bioactive Metabolites Produced by Pseudomonas aeruginosa against Candida Species

Abstract: Background: The frequency of fungal infections targeting immune-suppressed patients has been prominently rising day by day. Among these infections, Candidiasis is one of the most common life-threatening systemic fungal infections in recent years. These infections are challenging to treat because of the inconvenience of effective antifungal drugs. Therefore, the insufficiency of current drug regimens coupled with constant mutations by the fungi to develop drug resistance can pose a potential problem for future anti-fungal treatments. This frequent increase in drug-resistant fungi has directed attention toward the use of alternative therapy from natural sources. Objective: This study aimed to evaluate Pseudomonas aeruginosa for its antifungal potential against Candida species. Materials and Methods: This study was conducted at the Federal Urdu University of Arts, Science and Technology, Karachi, Pakistan during 2021-2022. For the detection of the antifungal compound, a clinical isolate P. aeruginosa HS 28 (identified conventionally as well as by 16S r RNA analysis) was screened for its bioactivity against Candida species by using agar well diffusion technique. The growth kinetics as well as the effect of different physical and chemical factors were also determined in the study. The compound was also partially purified by ammonium sulfate precipitation. Result: This antifungal compound showed good inhibitory activity against Candida species such as Candida albicans, C. glabrata, C. tropicalis, C. krusei, etc. This compound retained its stability at a high range of temperatures, and varying pH. Moreover, its bioactivity was also conserved when treated with organic solvents, chloroform vapors, metal salts, and different surfactants/detergents. The growth kinetics analysis illustrated that the maximum production of antifungal compounds occurred in the log phase of growth and extended supreme until the late log phase. Furthermore, the highest saturation of this protein was achieved at the concentration of 60% ammonium sulfate. Conclusion: The overall results indicated the promising antifungal potential of the compound produced by Pseudomonas aeruginosa HS 28 against Candida species.