Impediment to growth and yeast-to-hyphae transition in Candida albicans by copper oxide nanoparticles

• Published in: Biofouling (Chur, Switzerland) Switzerland), 2020-01, Vol.36 (1), p.56-72
• Main Authors: Padmavathi, Alwar Ramanujam, P., Sriyutha Murthy, Das, Arindam, Priya, Arumugam, Sushmitha, T. J., Pandian, Shunmugiah Karutha, Toleti, Subba Rao
• Format: Article
• Language: English
• Subjects: Antifungal activity; Antifungal Agents - pharmacology; Bioactive compounds; Candida albicans; Candida albicans - drug effects; Candida albicans - growth & development; Candida albicans - metabolism; Cell Membrane - drug effects; cell membrane integrity; Copper; Copper - pharmacology; Copper oxide nanoparticles; Copper oxides; Dimensions; DNA; ergosterol; Fungicides; Hyphae; Hyphae - drug effects; Hyphae - growth & development; Hyphae - metabolism; Metal Nanoparticles - chemistry; Microbial Sensitivity Tests; Minimum inhibitory concentration; Nanoparticles; Nucleotide sequence; Oxidation; PCR; Reactive oxygen species; Reactive Oxygen Species - metabolism; Regulators; ROS generation; Switching; Valence; Yeast; Yeasts; Zeta potential
• ISSN: 0892-7014; 1029-2454
• DOI: 10.1080/08927014.2020.1715371

The effects of two prominent copper oxide nanoparticles (CuO-NP and Cu 2 O-NP), with the oxidation state of Cu ++ (cupric) and Cu + (cuprous), on Candida albicans were evaluated. CuO-NP and Cu 2 O-NP were synthesized and characterized by XRD, FESEM, HR-TEM and Zeta potential. At sub-MIC (50 µg ml −1 ), both cupric and cuprous oxide NPs prevented yeast-to-hyphae switching and wrinkling behaviour in C. albicans. The mechanism for the antifungal action of the two NPs differed; CuO-NP significantly elicited reactive oxygen species, whereas membrane damage was more pronounced with Cu 2 O-NP. Real time PCR analysis revealed that CuO-NP suppressed the morphological switching of yeast-to-hyphae by down-regulating cph1, hst7 and ras1 and by up-regulation of the negative regulator tup1. In comparison, Cu 2 O-NP resulted in down-regulation of ras1 and up-regulation of the negative regulators nrg1 and tup1. Between the two NPs, CuO exhibited increased antifungal activity due to its stable oxidation state (Cu ++ ) and its smaller dimensions compared with Cu 2 O-NP.