Aspergillus flavus genetic structure at a turkey farm
Ghaya Cherif1,2, Ines Hadrich3, Myriam Harrabi2,4
1Laboratory of Parasitology and Mycology UR17SP 03, La Rabta Hospital, Tunis, Tunisia.
Background:
The ubiquitous environmental fungus Aspergillus flavus is also a life-threatening avian pathogen.
Objectives:
This study aimed to assess the genetic diversity and population structure of A. flavus isolated from turkey lung biopsy or environmental samples collected in a poultry farm.
Methods:
A. flavus isolates were identified using both morphological and ITS sequence features. Multilocus microsatellite genotyping was performed by using a panel of six microsatellite markers. Population genetic indices were computed using FSTAT and STRUCTURE. A minimum-spanning tree (MST) and UPGMA dendrogram were drawn using BioNumerics and NTSYS-PC, respectively.
Results:
The 63 environmental (air, surfaces, eggshells and food) A. flavus isolates clustered in 36 genotypes (genotypic diversity = 0.57), and the 19 turkey lung biopsies isolates clustered in 17 genotypes (genotypic diversity = 0.89). The genetic structure of environmental and avian A. flavus populations were clearly differentiated, according to both F-statistics and Bayesian model-based analysis' results. The Bayesian approach indicated gene flow between both A. flavus populations. The MST illustrated the genetic structure of this A. flavus population split in nine clusters, including six singletons.
Conclusions:
Our results highlight the distinct genetic structure of environmental and avian A. flavus populations, indicative of a genome-based adaptation of isolates involved in avian aspergillosis.
Insights
Environmental and avian Aspergillus flavus (A. flavus) populations show distinct genetic structures. This suggests genome-based adaptation in A. flavus isolates causing avian aspergillosis in poultry.
Area of Science:
- Mycology
- Veterinary Pathology
- Population Genetics
Background:
- Aspergillus flavus is a common fungus found in the environment.
- It is also a significant cause of life-threatening infections in birds.
Purpose of the Study:
- To investigate the genetic diversity and population structure of A. flavus.
- Samples were collected from turkey lungs and the farm environment.
Main Methods:
- Isolates were identified using morphology and ITS sequencing.
- Multilocus microsatellite genotyping was performed with six markers.
- Population genetic indices were calculated using FSTAT and STRUCTURE.
Main Results:
- Environmental A. flavus isolates (n=63) had 36 genotypes (diversity=0.57).
- Avian A. flavus isolates (n=19) had 17 genotypes (diversity=0.89).
- Environmental and avian populations showed distinct genetic structures, with evidence of gene flow.
Conclusions:
- Environmental and avian A. flavus populations exhibit different genetic structures.
- This indicates adaptation at the genomic level for isolates causing avian aspergillosis.
