Microsatellite typing of Aspergillus flavus from clinical and environmental avian isolates

Abstract

Aspergillosis is one of the most common causes of death in captive birds. Aspergillus fumigatus accounts for approximately 95 % of aspergillosis cases and Aspergillus flavus is the second most frequent organism associated with avian infections. In the present study, the fungi were grown from avian clinical samples (post-mortem lung material) and environmental samples (eggs, food and litter). Microsatellite markers were used to type seven clinical avian isolates and 22 environmental isolates of A. flavus. A. flavus was the only species (28 % prevalence) detected in the avian clinical isolates, whereas this species ranked third (19 %) after members of the genera Penicillium (39 %) and Cladosporium (21 %) in the environmental samples. Upon microsatellite analysis, five to eight distinct alleles were detected for each marker. The marker with the highest discriminatory power had eight alleles and a 0.852 D value. The combination of all six markers yielded a 0.991 D value with 25 distinct genotypes. One clinical avian isolate (lung biopsy) and one environmental isolate (egg) shared the same genotype. Microsatellite typing of A. flavus grown from avian and environmental samples displayed an excellent discriminatory power and 100 % reproducibility. This study showed a clustering of clinical and environmental isolates, which were clearly separated. Based upon these results, aspergillosis in birds may be induced by a great diversity of isolates.

Genetic Diversity and In Vitro Antifungal Susceptibility of 200 Clinical and Environmental Aspergillus flavus Isolates

“…The isolates were collected from different patients, from separate regions of Iran (Table 1), and were collected over an 8-year period. Similarly, the high genetic diversity in A. flavus was observed in clinical strains originating from humans (21) and animals (43). Furthermore, in a previous study, we also showed that clinical and environmental A. fumigatus strains from Iran clustered apart from each other (44).…”

Investigating Clinical Issues by Genotyping of Medically Important Fungi: Why and How?

“…For veterinary medicine, Hadrich et al described identical genotypes between avian isolates recovered from lung biopsy specimens and the environment of the birds using VNTR markers (83). The same authors also reported a high genetic diversity between human isolates and environmental and avian isolates (84), which is different from what was reported for A. fumigatus, where differences between the genotypes of avian and human isolates were not detected using STR markers (47).…”

Combined genotyping strategy reveals structural differences between Aspergillus flavus lineages from different habitats impacting human health

“…Sequences of the primer pairs designed for the microsatellite markers AFLA1, AFLA3, AFLA7, AFPM3, AFPM4, and AFPM7 are shown in Table . The PCR mixtures of 20 μl volume contained 10× DreamTaq Buffer (with 1.5 mM MgCl 2 ) (Thermo Scientific), 0.02 mM dNTPs, 4–4 pmol of forward and reverse primers, 10–100 ng of total DNA, 1 U DreamTaq DNA Polymerase (Thermo Scientific) and nuclease free water.…”