Isolation of Cryptococcus gattii from Oregon soil and tree bark, 2010-2011.

Emilio Debess,Naureen Iqbal,Shawn R Lockhart,Paul R Cieslak

doi:10.1186/s12866-014-0323-2

Emilio Debess, Naureen Iqbal + Show 2 more

Open Access

https://doi.org/10.1186/s12866-014-0323-2

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Abstract

BackgroundIn Oregon, human and animal infections by C. gattii were first identified in 2004. Cryptococcus gattii is considered to be an emerging non-zoonotic infection affecting animals and humans in Oregon. We report a longitudinal environmental isolation of C. gattii after an Oregon dog was diagnosed with the disease in 2009.ResultsCryptococcus gattii was isolated twice from the same location with a span of one year between isolation dates. Cryptococcus gattii molecular types VGIIa and VGI were isolated in 2010 from soil and tree bark near the home of a 9-month-old dog which three months previously had an infection caused by C. gattii genotype VGIIa. The environment featured heavy growth of Douglas Fir trees. In 2011, a second set of soil and tree bark samples was collected in the same area and C. gattii VGIIa was again identified from the environment, along with genotypes VGIIb and VGIIc.ConclusionsThe use of animal surveillance data to identify environmental niches of C. gattii should be considered to expand the understanding of this emerging pathogen. Understanding the ecology and how the environment and other factors might modify the existing niches is important for assessing risk and for designing measures to protect human and animal health.

Highlights

In Oregon, human and animal infections by C. gattii were first identified in 2004
In 1999, C. gattii infections emerged on Vancouver Island, British Columbia (BC)
Most infections were caused by C. gattii genotype VGII, but the strains lacked the genetic diversity seen among other VGII isolates from other countries and appeared to represent distinct clonal populations, dubbed genotypes VGIIa and VGIIb [9,10]

Summary

Results

Of the 12 samples obtained in 2010 around the home of the positive veterinary case, two yielded C. gattii; one soil sample had genotype VGIIa isolates, and another had isolates of both VGIIa and VGI (Table 1). Upon return to the same environs in 2011, C. gattii isolates of genotypes VGIIa, VGIIb and VGIIc were identified from the bark and soil samples taken along the logging road bordering the same property. The C. gattii VGIIa isolates from soil and bark were indistinguishable from the VGIIa isolate obtained from the dog

Conclusions

Background

Methods

Conclusion