14th ICID - Poster Abstracts - International Society for Infectious ...

When citing these abstracts please use the following reference:
Author(s) of abstract. Title of abstract [abstract]. Int J Infect Dis 2010;14S1: Abstract number.
Please note that the official publication of the International Journal of Infectious Diseases 2010, Volume 14, Supplement 1
is available electronically on http://www.sciencedirect.com
Final Abstract Number: 30.009
Session: Mycology, Fungal Infections and Antifungal Drugs
Date: Wednesday, March 10, 2010
Time: 12:30-13:30
Room: Poster & Exhibition Area/Ground Level
Type: Poster Presentation
Assessment of a novel region of the 28S rRNA operon for identification of clinically significant
Mucormycota
U. Kesavachandran, S. Hurst, L. Gade, A. Balajee
Centers for Disease Control and Prevention, Atlanta, GA, USA
Background: Mucormycosis is a frequently lethal invasive infection in high risk individuals
including transplant recipients and diabetic individuals. Members of these taxa are difficult to
identify by traditional methods in the clinical microbiology laboratory and in vitro differences in
antifungal susceptibility within the genera have been noted. Today, comparative sequences
based methods are considered the gold standards for rapid, accurate and objective species
identification of fungi. Although the rRNA regions including the 18S, ITS, 5.8S and D1-D2
hypervariable region of the 28S have been evaluated as targets, none have proven to be useful
as a "universal" locus for broad fungal identification. Recently, fredricks etal., analyzed a hitherto
unexplored region of the 28S rRNA gene for species identification of a wide range of fungal
genera. In the present study, we explored the utility of this target region for specific and
discriminatory identification of Mucormycota genera.
Methods: A total of 100 isolates representing 10 different medically important genera of
Mucormycota from the culture collections of the Centers for Disease Control and Prevention
(CDC), Atlanta, GA, and the National Center for Agricultural Utilization Research, U.S.
Department of Agriculture, Peoria, IL were used in this study. Genomic DNA was extracted using
Qiagen kit and PCR amplification and sequencing of the extended 28S rRNA was performed as
previously described. Sequences were aligned using Clustal W and distance matrices were
generated using the Biolomics software.
Results: PCR products were generated for all the isolates tested and amplicon size differences
were detected among the genera. Accordingly, large regions of insertion/deletion were observed
when the sequences were aligned. Distance matrices and phylogenetic analyses revealed
appreciable nucleotide differences among the genera tested.
Conclusion: In summary, the novel 28S r RNA region evaluated in this study was readily
amenable to PCR/sequencing and revealed genus specific nucleotide differences, thus holding
promise as a target for discriminatory genus identification of Mucormycota.