Tackling drug resistant pathogenic fungi through antimicrobial nanostructured surfaces

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Naga Venkatesh Kollu (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Dennis LaJeunesse

Abstract: Candida albicans is a common member of the human gut, skin and mucosal microbiomes. Systemic C. albicans infections are of special concern for immunocompromised patients such transplant recipients and AIDS patients. Drug resistant strains of C. albicans are an enormous health concern and like most antibiotic resistant microbes pose a greater risk due to the concomitant acquisition of traits associated with pathogenicity. Traditionally microbial control involves antibiotics that target specific essential enzymes; however, over the past fifty years there has been an exponential increase in resistance of pathogenic bacteria and fungi to known antibiotic compounds. Recent developments in electron microscopy have made the study of naturally occurring nano and micro-scale hierarchical structures specially on insect wings, lotus leaves, shark skin, gecko skin yielding to their super hydrophobic and antimicrobial responses. Nanostructured surface (NSS) are attractive alternatives to chemical antibiotics because they will not be susceptible to the same pathways towards resistance as chemical agonists. Recent work has shown that microbes including gram negative bacteria and cellular yeast are vulnerable to mechanical assaults via surfaces that exhibit high-aspect ratio nanoscale topographies. Though extensive research has been done in mimicking naturally occurring NSS and designing new surfaces for antibacterial use, efficacy as antifungal agents specially against pathogenic fungi like C. albicans has been ignored. The long-term goals of my project are to define the properties of nano structured materials and use these properties for the design and application of novel materials that control pathogenic fungal growth and biofilm formation. In this research I have characterized the nanoscale mechanical interactions between C. albicans cells and the cell-rupturing nanostructured surface from the wing of the Cicada Tibicen ssp; and have defined the timing and the conditions that control NSS-induced C. albicans cell rupture. I have found that the NSS changes the cell wall composition of this cellular yeast and that the NSS induced rupture of this microbe is significantly slower than NSS rupture of bacteria on similar surfaces. Different drug resistant strains of C. albicans displayed altered responses of rupture and morphogenesis which is attributed to the mechanism of drug resistance developed in them. Biofilm production which is responsible for the virulence and development of resistance in Candida sps. is also significantly reduced when incubated on NSS. Finally, I demonstrate data showing Nano-cones on the cicada wing inhibit the transformation of yeast to hyphae thus reducing pathogenicity of C. albicans. Following this I used synthetic biocompatible NSS as coatings on catheters to determine their antifouling and antifungal efficacy in comparison to flat surfaces. This research is extremely necessary for a systematic study of microbial interaction with the Nanostructured surfaces and define properties to synthesize novel anti-microbial polymers which can be used as coating on indwelling medical devices to improve their lifespan and as coatings in the areas of sanitation.

Additional Information

Language: English
Date: 2020
Anti-microbial surfaces, Biofilm formation, Candida albicans, Hyphal morphogenesis, Mechanical cell-rupture, Nanostructured surfaces
Candida albicans
Drug resistance
Nanostructured materials $x Surfaces

Email this document to