Aneuploidy is an unbalanced chromosome complement: one or more chromosomes present in extra or missing copies. It has long been tied to drug resistance in human pathogenic yeasts — Candida albicans, Cryptococcus neoformans, Candida glabrata, Candida auris — where duplicating a chromosome lets the cell withstand azoles and other stressors without any point mutation at all.

Aspergillus flavus is a filamentous fungus that contaminates major crops with aflatoxins, and it is also the second leading cause of human invasive aspergillosis after A. fumigatus. Azoles are the front-line control in both settings. Resistance in Aspergillus is normally attributed to point mutations in cyp51 orthologues, overexpression of those genes, or efflux pumps lowering the effective drug concentration.

We found an aflatoxigenic A. flavus strain adapting to voriconazole above its MIC through whole and segmental aneuploidy of specific chromosomes — the first experimental evidence of this in a filamentous fungus. Whole-genome sequencing of eight voriconazole-resistant isolates confirmed complete duplication of chromosome 8 in two sequentially isolated clones and a segmental duplication of chromosome 3 in another. That matters because it's fast, it needs no mutation, and it's reversible: repeated transfer on drug-free media returns the clones to their original azole susceptibility. A dosage mechanism, not a sequence one.

The antifungal arsenal is thin and resistance is spreading, so we look for activity in places under real selection pressure: plants that resist fungal attack, carnivorous pitchers that hold digestive fluid without rotting, marine sponges, and agricultural by-products that would otherwise be waste.

Pomegranate peel extract is the clearest case. On its own it suppresses mycotoxigenic fungi; combined with an azole fungicide it acts synergistically, inhibiting both growth and toxin output at doses where neither compound works alone. We've taken the same extract into the ensiling process as a natural additive against fungal and mycotoxin contamination in silage. We've also characterised antifungal naphthoquinones induced in Nepenthes khasiana pitchers, a compound from the sponge Dysidea herbacea, and zinc chloride against A. flavus.

Synergy is the point. A natural product that lets you use less azole, or that closes off a resistance route, is worth more than one that simply kills things in a dish.

Mycotoxin contamination is heterogeneous and it moves with the goods. Regulatory limits exist for aflatoxins, ochratoxin A, fumonisins, patulin and the rest, but enforcing them depends on being able to measure quickly, cheaply and at the point the decision is made — at intake, in storage, on the packing line.

With Giorgi Shtenberg's group we develop surface-enhanced Raman scattering platforms on silver-coated porous silicon, including reusable substrates and a microarray that reads aflatoxin B₁, fumonisin B₁ and ochratoxin A together. We've compared aptasensor against immunosensor architectures on the same Ag-pSi substrate for ultrasensitive AFB₁ detection, and built a porous-silicon Fabry-Pérot interferometer for AFB₁ in field crops. In parallel we run chromatographic and mass-spectrometric methods for patulin and citrinin in fruit, and rapid identification of mycotoxigenic fungi and their toxins in stored wheat grain.

Detection and regulation are the same question asked twice. Knowing which conditions switch a cluster on tells you when to look; knowing how to look tells you whether the regulation work was right.