title: Simple and highly discriminatory VNTR-based multiplex PCR for tracing sources of Aspergillus flavus isolates.
abstract: Aspergillus flavus is second only to A. fumigatus in causing invasive aspergillosis and it is the major agent responsible for fungal sinusitis, keratitis and endophthalmitis in many countries in the Middle East, Africa and Southeast Asia. Despite the growing challenge due to A. flavus, data on the molecular epidemiology of this fungus remain scarce. The objective of the present study was to develop a new typing method based on the detection of VNTR (Variable number tandem repeat) markers. Eight VNTR markers located on 6 different chromosomes (1, 2, 3, 5, 7 and 8) of A. flavus were selected, combined by pairs for multiplex amplifications and tested on 30 unrelated isolates and six reference strains. The Simpson index for individual markers ranged from 0.398 to 0.818. A combined loci index calculated with all the markers yielded an index of 0.998. The MLVA (Multiple Locus VNTR Analysis) technique proved to be specific and reproducible. In a second time, a total of 55 isolates from Chinese avian farms and from a Tunisian hospital have been evaluated. One major cluster of genotypes could be defined by using the graphing algorithm termed Minimum Spanning Tree. This cluster comprised most of the isolates collected in an avian farm in southern China. The MLVA technique should be considered as an excellent and cost-effective typing method that could be used in many laboratories without the need for sophisticated equipment.
authors.affiliation: Parasitology Department, College of Animal Science and Technology, Guangxi University, Nanning, China.
authors.forename: Dong Ying
authors.initials: DY
authors.lastname: Wang
authors.forename: Leila
authors.initials: L
authors.lastname: Hadj-Henni
authors.forename: Simon
authors.initials: S
authors.lastname: Thierry
authors.forename: Pascal
authors.initials: P
authors.lastname: Arné
authors.forename: René
authors.initials: R
authors.lastname: Chermette
authors.forename: Françoise
authors.initials: F
authors.lastname: Botterel
authors.forename: Inès
authors.initials: I
authors.lastname: Hadrich
authors.forename: Fattouma
authors.initials: F
authors.lastname: Makni
authors.forename: Ali
authors.initials: A
authors.lastname: Ayadi
authors.forename: Stéphane
authors.initials: S
authors.lastname: Ranque
authors.forename: Wei Yi
authors.initials: WY
authors.lastname: Huang
authors.forename: Jacques
authors.initials: J
authors.lastname: Guillot
mesh_terms: D001231:Aspergillus flavus / Q000145:classification / Q000235:genetics*; D018598:Minisatellite Repeats / Q000235:genetics*; D058885:Multilocus Sequence Typing; D060885:Multiplex Polymerase Chain Reaction; D010802:Phylogeny