A middle school science fair project has solved a microbial mystery. Elan Filler helped to identify the source of a life-endangering fungus in southern California. She tagged three Californian trees as the source of the puzzling infection.
The fungus Cryptococcus gattii has been causing illness and even death for decades. It may be that up to one third of HIV/AIDS related deaths in southern California are caused by C.gattii. Although many people with auto-immune deficiencies are infected by the fungus, scientists did not know where the fungus was occurring naturally. In Australia and the Pacific Northwest the fungus is associated with trees so it would make sense to look at trees in southern California also. However, the lead researcher for C. gattii, Deborah Springer, Ph.D., is based at Duke University in North Carolina. She had neither the time nor the resources to test California trees.
Then Springer’s advisor, Dr. Joseph Heitman, met Elan’s father, infectious disease specialist Dr. Scott Filler, at a medical conference. Elan became the “boots on the ground” for Springer’s research. She swabbed trees and grew fungal samples in Petri dishes which she shipped to Springer for analysis. When the usual suspect, eucalyptus trees, tested negative for the fungus, Elan expanded her swabbing to other species in the area. Soon, three varieties of trees proved positive as hosts for the fungus. Canary Island pine, New Zealand pohutukawa and American sweet gum carried the same strain of the fungus that was infecting and killing patients. Elan’s middle school science fair project solved the microbial mystery of which trees in southern California supported the dangerous fungus.
According to Springer, the fact that C. gattii grows on trees makes it especially virulent in mammalian victims such as humans. When introduced into a human host it can quickly colonize the brain and lung tissue and cause death. Other forms of Cryptococcus are associated with birds and bats and infect humans when dried feces are inhaled. Springer’s research and other medical analysis show that C. gatii, which is inhaled with plant matter, is much more potent and can cause serious problems for immunocompetent people as well as immunocompromised. Now that the mystery has been solved, patients may benefit from with faster diagnoses.
Symptoms for Cryptococcosis range from fever to pleuratic chest pain and a cough to meningitis or encephalitis. Any person with a compromised immune system, such as HIV, cancer or undergoing chemotherapy, should be careful and seek medical care if they suspect infection. Knowing which trees could cause problems assists with earlier diagnosis and treatment of the disease caused by the fungus. The disease can have a death rate of 20-30 percent for those who are diagnosed late or are immunosuppressed. Also, up to 25 percent of patients suffer recurring issues and may spend years on antifungal drugs. The abstract of Springer’s study states, “Taken together, our studies reveal an environmental source and risk of C. gattii to HIV/AIDS patients with implications for the >1,000,000 cryptococcal infections occurring naturally for which the causative agent is rarely assigned species status. Thus, the C. gattii global health burden could be more substantial than currently appreciated.”
The research paper on C. gattii was published by Deborah Springer last week and listed Elan Filler as a coauthor, but Filler is already on to new fungi. She spends her summers at the L.A. Biomedical Research Institute conducting research alongside her father. A sophomore at Palos Verdes High School last year, Filler won top honors in the Los Angeles county science fair for her work on Candid glabrata. C. glabrata is a fungus that is a naturally occurring part of the human microbiome but that can enter the bloodstream and cause fatal infections in those with weakened immune systems. Filler focused on why it develops resistance to antifungal drugs. Perhaps her early work swabbing trees has set her on a course to be a leading fungal expert.
The identification of the three trees that host C. gattii can help people avoid infection as well as aid doctors in quicker diagnosis. It is amazing that a seventh grade student looking for a research idea could be instrumental in the research on a potentially deadly virus. Her middle school science fair project solved a microbial mystery.
By: Rebecca Savastio