Effects of Microampere-Scale Wireless Conductive Microelectrostimulation on the Growth of Aspergillus fumigatus in Single-Dish Electroculturomics Setup

Exposure to electric amenities, both fields and current, affects microbial growth. Its systematic study in species, substrates and specific settings defines electroculturomics. In this context, the effect of microcurrents on facultative microbial pathogens remains controversial, and thus restricts the wide clinical use of such amenities. This study presents preliminary observations in a low-replicate in vitro system. Solid cultures in Sabouraud Glucose Agar of the ubiquitous mold Aspergillus fumigatus were repeatedly treated with a commercially available device performing wireless conductive microelectrostimulation by a 3.5 μA (microAmpere) microcurrent routed by spraying negatively charged air particles onto solid cultures in modified Petri dishes. The treated cultures displayed increased lateral growth compared to standard ones, shown as visually apparent differences in mycelial texture; the radial growth rate of the mycelium remained unaltered. The increased growth was positively related to the duration of the treatment. At the same time, secondary development (new mycelial loci within the dish) was considerably increased due to treatment, possibly due to the spraying effect, which creates micro-airstreams that dislocate the fungal spores. These results, derived without technical or biological repeats, imply complex kinetics of mycelial growth with and without treatment, since the folding of the mycelial mat is observed regularly. The fungus’s response to the electrostimulation might translate into prospects for biotechnological and bioremediation applications but may also imply biomedical complications, regarding infection dynamics of mycelial fungi and their in situ resistance to immune responses and therapeutic treatment if subjected to such electrostimulation treatment in situ.