Background and Importance Moulds are aerobic eukaryotic organisms naturally present in the environment. According to regulations, no mould should be present in a controlled- atmosphere zone (ZAC).

According to the literature, fungal spores can reach significant quantities, up to several 10, 000’s of particles/m³ of ambient air. The highest concentrations are found during the summer-autumn period in Europe. Cladosporium spp is the predominant species in most studies, with concentrations of over 4,000 CFU/m³ of ambient air.

The trend in outdoor air contamination is well known, but few articles deal with the trend in fungal contamination in ZACs.

Aim and Objectives The primary objective of this study was to determine whether there is a seasonal trend in contamination in ZACs. The secondary objectives were to determine the most frequent moulds and the effect of factors such as air conditioning, hygrometry and temperature on fungal contamination in ZACs.

Material and Methods Based on microbiological surveillance register of the ZACs at the Saint-Ismier cell therapy and engineering unit, we collected the contaminated samples without counting the number of CFUs contained in this contamination. When available, identification was provided. The variables of temperature, hygrometry and air conditioning were collected using centralised technical management software for equipment and premises. All the data collected was recorded manually in a Microsoft Excel spreadsheet, with data double-checked at the time of collection. Statistical tests were performed on this table.

Results The results of the trend analysis showed a significant difference between fungal contamination frequencies in ZACs depending on the season. Autumn and summer are the seasons with the highest risk of fungal contamination. The main species in our study were Cladosporium, spp and Penicillium, spp.

Conclusion and Relevance These results show that the evolution of fungal contamination in ZACs reflects that of external environment. Indeed, although ZAC air treatment systems are capable of filtering large quantities of fungal spores, factors such as personnel, materials and consumables are potential vectors for microbial transfer.

References and/or Acknowledgements 1. Avis de l’Anses Rapport d’expertise collective.pdf.

2. Basilico M de la LZ, Chiericatti C, Aringoli EE, Althaus RL, Basilico JC. Influence of environmental factors on airborne fungi in houses of Santa Fe City, Argentina. Sci Total Environ. 15 avr 2007;376(1):143–50.

Conflict of Interest No conflict of interest.