Variability of germinative potential among pathogenic species of Aspergillus

Abstract

The objective of our study was to evaluate parameters influencing the germination of Aspergillus conidia. Inoculum concentration and age significantly influenced germination. Different incubation temperatures revealed significant differences among Aspergillus species. The internal human milieu provides the ideal conditions for the development of invasive disease by Aspergillus fumigatus but restricts invasion by Aspergillus flavus and Aspergillus niger.

FIG. 1.

Inhibitory effect of concentrations of growing inoculum on the germination rate of 5-day-old A. fumigatus conidia after 8 h of incubation in RPMI 1640 medium at 37°C. Each point represents the mean value ± standard error of the mean for all tested strains of A. fumigatus.

FIG.2.

Kinetics of germination of 5-day-old conidia of the three tested species of Aspergillus during 12 h of incubation in RPMI 1640 medium at 37°C. Each point represents the mean value ± standard error of the mean for all tested strains of each Aspergillus species.

FIG. 3.

Percentage of germination by 5-day-old conidia of the three tested Aspergillus species after incubation for 8 h in RPMI 1640 medium at different temperatures. Each point represents the mean value ± standard error of the mean for all tested strains of each Aspergillus species.

FIG. 4.

Effect of different acidic pH values produced by the addition of AA, HA, and LA on the germination rate of 5-day-old conidia of different Aspergillus species. Each bar represents the mean value + standard error of the mean for all tested strains of each Aspergillus species after 8 h of incubation in RPMI 1640 medium at 37°C.