Objective. Aspergillosis is a common systemic mycosis in birds and one of the most important causes of death in captive animals, especially penguins. Inadequate ventilation and dusty conditions increase the risk of bird exposure to aerosolized Aspergillus spores. Only few data are available about Aspergillus air contamination in zoological parks. The objective of the present study was to perform a long-term monitoring of the air contamination by Aspergillus spp. in a zoological park in France. 

Methods. The study was performed in the zoological park of Vincennes, Paris. This park shows a large number of wild birds, including a colony of 20 Humboldt penguins (Spheniscus humboldti). The park also includes specific facilities for incubation and hatching of bird eggs. The monitoring of Aspergillus contamination was performed every two weeks, from January to December 2016. Air samples (300 L) were collected using the Air Strategie Bio-impactor device loaded with Sabouraud dextrose agar plates in 8 sites: 3 inside the bird nursery, 1 in a corridor close to the nursery and 4 inside nests of Humboldt penguins. To select thermophilic fungi, plates were incubated at 37°C for 4 days. Fungal colonies were subcultured and identified according to their macroscopic and microscopic appearance. Further proteomic identification (MALDI-TOF) was performed for selected isolates.

Results. Aspergillus spp. were recovered from almost every sample. The predominant species was A. fumigatus which was recovered from 77.8% and 45.5% of air samples collected from the penguin nests and the bird nursery, respectively. Aspergillus niger and A. flavus were also regularly isolated. The species A. nidulans was detected in rare occasions from the nursery. The levels of Aspergillus contamination in penguin nests were below 30 colony-forming units (CFU)/m3 and did not vary throughout the year round sampling period. The levels of Aspergillus contamination in the nursery were below 10 CFU/m3 except in two occasions (in March and November) with higher loadings (up to 100 CFU/m3) of A. fumigatus. It was not possible to find the origin of these unusual levels of contamination and during the study no clinical case of aspergillosis was diagnosed in the penguin colony.

Conclusion. This is the first study of environmental Aspergillus contamination in a French zoological park. Background levels of Aspergillus spores in the nursery and in penguin nests were low, but occasional exceptions occurred in the nursery. The predominant Aspergillus species present was A. fumigatus, but other species were also detected.

Aspergillus spp. aerocontamination in a zoological park in France: results of one-year monitoring in a bird nursery and penguin nests