Researchers at Duke University have identified the sources of a tree fungus responsible for one-third of AIDs-related deaths in the U.S.

And they did it with the help of a budding 13-year-old scientist from California.

Dr. Deborah J. Springer is a senior postdoctoral fellow at the Dept. of Microbial Pathogenesis at Duke University School of Medicine.

She’s the lead author of a new study in PLOS Pathogens, an online journal of “peer-reviewed papers on bacteria, fungi, parasites, prions and viruses.”

A few years ago, 13-year-old Elan Filler – she’s now 16 – was connected to Springer through her dad, infectious disease specialist Scott Filler, MD.

Elan was looking for a fun science fair project, so she spent her summer swabbing tree trunks around Los Angeles, in hopes of helping Springer find out if certain trees were growing the fungus Cryptococcus gattii.

“Historically, Cryptococcus has been reported in HIV and AIDS patients in California,” said Springer. “Approximately 11 percent of those HIV-positive status for Cryptococcus infections are a result of Cryptococcus gattii.

Elan placed each sample onto an agar – a gelatinous polymer used as a culture medium in laboratories.

By that method, Cryptococcus yeast cells were differentiated from other yeast cells by a blue color change on the specialized agars known as CGBs.

“And then she sent those isolates to me for molecular analysis,” said Springer.

Springer DNA-sequenced the California samples and compared them to those taken from HIV/AIDS patients with C. gattii infections.

To her surprise, samples from three of the tree species were almost genetically indistinguishable from the patient samples.

Those samples came from the Canary Island pine, New Zealand pohutukawa and the American sweet gum.

The finding allows health experts to warn people who live in, or plan to visit California, the Pacific Northwest or Oregon of the heightened risk for developing a fungal infection if one’s immune system is compromised.

“We had all these public health cases occurring, but we couldn’t find it in the environment,” said Springer. “So there was a real discontinuity between the environmental occurrence – what we knew – and what was happening in the patients.”