Zinc Oxide Nanoparticles Suppress Microsporum canis Growth and Virulence Original paper
Researched by:
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Karen Pendergrass
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Karen Pendergrass
Read MoreKaren Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.
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Microbes
Microbes
Microbes, short for microorganisms, are tiny living organisms that are ubiquitous in the environment, including on and inside the human body. They play a crucial role in human health and disease, functioning within complex ecosystems in various parts of the body, such as the skin, mouth, gut, and respiratory tract. The human microbiome, which is […]
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Karen Pendergrass
Read More
Researched by:
-
Karen Pendergrass
ID
Karen Pendergrass
Read More
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Karen Pendergrass
What was studied?
This original study investigated the in vitro antifungal efficacy of zinc oxide nanoparticles against clinical isolates of Microsporum caniscollected from dogs and cats, and evaluated their impact on the dermatophyte virulence gene SUB1, which encodes a subtilisin protease involved in fungal adhesion. The authors synthesized ZnO nanoparticles through a modified wet-chemical method, confirmed nanoparticle morphology and purity through XRD and electron microscopy, quantified antifungal activity through CLSI-standard disk diffusion, microdilution, MIC and MFC assays, and assessed SUB1 expression via qRT-PCR.
Who was studied?
Forty-three veterinary patients (dogs and cats) presenting to the University of Tehran Small Animal Hospital for suspected dermatophytosis were initially screened, from which ten confirmed M. canis isolates were obtained through Wood’s lamp evaluation, McKenzie brush sampling, cultural identification, and microscopic verification. These ten isolates were used for all antifungal susceptibility and gene-expression analyses.
Most important findings
Zinc oxide nanoparticles exhibited consistent, concentration-dependent inhibition of M. canis. Disk diffusion assays demonstrated inhibitory activity across dilutions of 250–4000 ppm, with maximum inhibition at 4000 ppm (mean zone diameters approximately 30–34 mm across isolates). MIC values ranged from 250–500 ppm and MFC values from 500–1000 ppm, yielding MFC-to-MIC ratios indicative of fungicidal activity. Sub-MIC exposure (125–250 ppm) significantly reduced SUB1 expression across isolates (p <0.05), suggesting disruption of protease-mediated adhesion pathways that are key determinants of keratin invasion and surface colonization.
For microbiome-signature applications, this study contributes a mechanistic anchor linking ZnO nanoparticles to attenuation of dermatophyte virulence rather than solely growth inhibition. Downregulation of SUB1 highlights a functional pathway that may be incorporated into future Major Microbial Association (MMA) analyses for dermatophytosis, particularly given that M. canis pathogenicity in hosts relies on proteolytic degradation of keratinized tissues.
In the context of translational microbiome medicine, nanoparticle-mediated suppression of virulence factors is relevant for intervention design targeting biofilm formation, adhesion processes, and protease-driven dysbiosis. These findings suggest that ZnO nanoparticle formulations could be explored as adjunctive or alternative antifungal interventions in cases characterized by resistance to azoles or terbinafine, although safety and in vivo pharmacodynamics require further investigation.
Greatest implications of the study
The study demonstrates that zinc oxide nanoparticles constitute a potent antifungal and anti-virulence agent against M. canis, with fungicidal properties and transcriptional interference of a key pathogenicity gene. These data support the feasibility of nanoparticle-based antifungal strategies in veterinary medicine and underscore their potential value in contexts where conventional antifungals fail due to resistance or inconsistent tissue penetration. The mechanistic evidence related to SUB1 suppression offers a novel targetable virulence axis for microbiome-oriented therapeutics. As dermatophyte-associated dysbiosis extends beyond visible lesions and may influence local immune dynamics, this work strengthens the rationale for integrating nanoparticle-based modalities into broader microbiome-targeted intervention frameworks.
Citation
Khanipour Machiani M, Jamshidi S, Nikaein D, Khosravi A, Balal A. The inhibitory effects of zinc oxide nanoparticles on clinical isolates of Microsporum canis in dogs and cats. Vet Med Sci. 2024;10:e1316. doi:10.1002/vms3.1316