Subsurface pressure profiling: a novel mathematical paradigm for computing colony pressures on substrate during fungal infections

Abstract

Colony expansion is an essential feature of fungal infections. Although mechanisms that regulate hyphal forces on the substrate during expansion have been reported previously, there is a critical need of a methodology that can compute the pressure profiles exerted by fungi on substrates during expansion; this will facilitate the validation of therapeutic efficacy of novel antifungals. Here, we introduce an analytical decoding method based on Biot’s incremental stress model, which was used to map the pressure distribution from an expanding mycelium of a popular plant pathogen, Aspergillus parasiticus. Using our recently developed Quantitative acoustic contrast tomography (Q-ACT) we detected that the mycelial growth on the solid agar created multiple surface and subsurface wrinkles with varying wavelengths across the depth of substrate that were computable with acousto-ultrasonic waves between 50 MHz–175 MHz. We derive here the fundamental correlation between these wrinkle wavelengths and the pressure distribution on the colony subsurface. Using our correlation we show that A. parasiticus can exert pressure as high as 300 KPa on the surface of a standard agar growth medium. The study provides a novel mathematical foundation for quantifying fungal pressures on substrate during hyphal invasions under normal and pathophysiological growth conditions.

Citrate-Coated Silver Nanoparticles Growth-Independently Inhibit Aflatoxin Synthesis in Aspergillus parasiticus

“…This information is critical in the realistic evaluation of the impact of NP accumulation on ecological physiology and human health. Here we address this knowledge gap using the plant pathogen, Aspergillus parasiticus , our laboratory’s model for studying fungal secondary metabolism. − This filamentous fungus synthesizes aflatoxin B 1 , a carcinogenic mycotoxin that contaminates billions of dollars’ worth of crops worldwide including corn, peanuts, treenuts and cotton. , Hence, it is a well characterized and established model for investigating molecular mechanisms underlying fungal secondary metabolite syntheses that are connected with significant economic and health implications.…”

Material State Awareness for Composites Part II: Precursor Damage Analysis and Quantification of Degraded Material Properties Using Quantitative Ultrasonic Image Correlation (QUIC)

“…To visualize the degraded material properties or development of micro-cracks across the depth of the specimens, ~50 MHz, and ~100 MHz transducers were used to perform the C-scans and X-scans. More details on this technique can be found in the operation principles of scanning acoustic microscopy (SAM) [ 23 , 24 ].…”