Optimization of the preparation of a spiny spore high-concentrated Aspergillus brasiliensis suspension

Lett Appl Microbiol. 2025 Jan 6;78(1):ovae141. doi: 10.1093/lambio/ovae141.

Abstract

This work aimed to improve some steps of the existing guidelines of the European Standards to obtain an Aspergillus brasiliensis ATCC 16404 spore suspension with >75% spiny spores without mycelia and a concentration of at least 1.5 × 108 CFU ml-1. Several manufacturers' combinations of "strain/medium" were assessed in terms of yield of spiny spores. Criteria to establish success included (i) the growth over different times of incubation (4, 7, and 10 days); (ii) the performance of two different filtration devices (fritted filters and cell strainers); and (iii) the fungal spores susceptibility after 4 days of incubation versus 7 days of incubation against a peracetic acid-based disinfectant. The best combination was "Microbiologics strain/Oxoid MEA" with 88.33% of spiny spores already after 4 days, and no statistical differences (P < .05) in terms of growth in the three time points were highlighted (from 1.85 × 108 CFU ml-1 to 2.21 × 108 CFU ml-1). Cell strainers gave a spore suspension much more concentrated (3.31 times) compared to fritted filters. Furthermore, the 4-day-old spore suspension showed the same susceptibility to disinfection when compared to a suspension whose culture was incubated for 7 days.

Keywords: Aspergillus brasiliensis; analytical/rapid methods; applied microbiology; disinfection; molds; pathogenic fungi.

MeSH terms

  • Aspergillus* / growth & development
  • Culture Media / chemistry
  • Disinfectants / pharmacology
  • Filtration / methods
  • Peracetic Acid / pharmacology
  • Spores, Fungal* / growth & development

Substances

  • Culture Media
  • Disinfectants
  • Peracetic Acid

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