Purpose: The genetic relationship between clinical and environmental isolates of Aspergillus fumigatus can be studied using genetic fingerprinting with DNA-based methods. Methods: In the present study, we used a new molecular typing method for Aspergillus fumigatus: the Multi Locus Variable Number tandem Repeat Analysis. This method is based on the detection of small genomic sequences (greater than 9 bp) repeated at least 3 times. Ten VNTR markers localized on 4 different chromosomes were selected for their applicability and discriminatory power (Simpson’s Diversity Index of 0.9994). A total number of 208 independent isolates were tested (145 isolates from birds principally isolated from two duck farms in Pays-La-Loire region in France, 62 isolates from one chicken and one duck farm from Guangxi Province in China and the reference strain CBS 144.89). After DNA extraction, amplification was obtained with the ten different couples of primers with the same PCR program. Amplicons were separated on agarose gel and the results were analysed using a specific software (Quantity One, Biorad). Results: This analysis generated 190 different patterns. We performed MST construction by using the Bionumerics software version 4.6 (Applied Maths, St. Martens-Latem, Belgium) for the all 208 isolates and strains based on the VNTR genotyping. The minimum spanning tree analysis demonstrated an interesting clustering of avian A. fumigatus isolates. Conclusions: A geographic clustering of the isolates could be detected. A first cluster included most of the isolates from France whereas the second one included most of the isolates from China.
Full conference title:
4th Advances Against Aspergillosis
- AAA 4th (2010)