643. Multi-Locus Sequence Typing of Coastal Pacific Northwest Cryptococcus Isolates
Session: Abstracts: Mycology
Friday, October 22, 2010
Background:

Cryptococcus gattii is an endemic fungal pathogen in British Columbia and the Pacific Northwest.  This study evaluated the role of multi-locus sequence typing (MLST) for speciation as well as its usefulness in determining molecular epidemiological trends in Cryptococcus isolated from this area.

Methods:

Cryptococcus spp. (n=107) were isolated using CGB agar media from clinical, veterinary and environmental samples.  Two molecular typing methods were used in this study. Restriction Fragment Length Polymorphism (RFLP) targeted to the URA5 gene, and MLST targeted to 7 loci (CAP59, GPD1, LAC1, PLB1, SOD1, URA5 and IGS1) were analyzed with a combined database.

Results:

MLST is able to identify all RFLP genotypes of C. gattii and provide greater typing resolution. It can further discriminate the RFLP genotype VGI into 7 MLST sequence types, VGIIa into 3, VGIIb in to 2, and VGIII into 2.  The results also show that the majority of the isolates within the Pacific Northwest region have identical sequences in 4100bp over 7 loci to each other.

Conclusion:

Despite the expense and labour-intensive nature of MLST, it provides greater molecular epidemiological detail, that is not possible with RFLP. More than 70% of the isolates from this region was MLST sequence type VGIIa_1. Since this predominant strain was observed in a variety of clinical, veterinary, and environmental isolates, it reflects the clonal nature of C. gattii infection in the Pacific Northwest and its origin on Vancouver Island.  Since MLST has become the international standard for Cryptococcus typing, we hope to integrate our database internationally for exchange, and to view the Pacific Northwest isolates from a global perspective in the near future.


Subject Category: M. Mycology including clinical and basic studies of fungal infections

Speakers:
Min-Kuang Lee, MS , BCCDC Public Health Microbiology and Reference Laboratory, Provincial Health Services Authority, Vancouver, BC, Canada
Stephanie Man, BS , BCCDC Public Health Microbiology and Reference Laboratory, Provincial Health Services Authority, Vancouver, BC, Canada
Andrew Balbirnie, BS , BCCDC Public Health Microbiology and Reference Laboratory, Provincial Health Services Authority, Vancouver, BC, Canada
Sultana Mithani, BS , BCCDC Public Health Microbiology and Reference Laboratory, Provincial Health Services Authority, Vancouver, BC, Canada
Quantine Wong, BS , BCCDC Public Health Microbiology and Reference Laboratory, Provincial Health Services Authority, Vancouver, BC, Canada
Deema Al-Okaily, MD , BCCDC Public Health Microbiology and Reference Laboratory, Provincial Health Services Authority, Vancouver, BC, Canada
Linda MN Hoang, MD, FRCPC , BCCDC Public Health Microbiology and Reference Laboratory, Provincial Health Services Authority, Vancouver, BC, Canada
Muhammad G. Morshed, PhD , BCCDC Public Health Microbiology and Reference Laboratory, Provincial Health Services Authority, Vancouver, BC, Canada

Disclosures:

M. K. Lee, None

S. Man, None

A. Balbirnie, None

S. Mithani, None

Q. Wong, None

D. Al-Okaily, None

L. M. Hoang, None

M. G. Morshed, None

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