Evaluation of a fluorescent amplified fragment length polymorphism (FAFLP)methodology for the genotypic discrimination of Aeromonas taxa

A fluorescent amplified fragment length polymorphism (FAFLP) fingerprinting assay is evaluated for its ability to differentiate DNA hybridization grou ps in the genus Aeromonas. After empirical determination of optimal assay c onditions using a limited set of strains, 98 well-characterized type and re ference strains encompassing all known Aeromonas taxa were subjected to FAF LP fingerprinting using the standardized protocol. The present study clearl y indicates that the use of fluorescent dye-labeled primers does not signif icantly affect the high capacity of this technique to differentiate among g enotypically closely related Aeromonas taxa. Compared to the original AFLP protocol involving the application of radioisotopes, the new FAFLP technolo gy offers a better performance when considering speed of analysis and user safety. On the other hand, FAFLP fingerprints exhibited a significant reduc tion in the relative number of bands compared to the corresponding autoradi ographic patterns. In our hands, the omission of the preselective amplifica tion step and the use of a size standard mix enhanced the cost effectivenes s and the reproducibility of the technique. Cluster analysis of FAFLP band patterns generated from Aeromonas type and reference strains demonstrated o nce more the high correlation of AFLP-generated data with DNA-DNA homology data. (C) 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.