Tree Fungus Mutated To Infect Humans

A 61-year-old man has become the world’s first recorded person to get sick from a fungus that normally attacks rose plants.

The case is a rare example of a plant pathogen crossing over into humans, according to a report in Medical Mycology Case Reports.

Although the man was eventually treated and cleared of the infection, the incident could illustrate the growing danger that fungi pose to people in the years to come, the doctors say.

The man visited an outpatient clinic in India with symptoms of cough, fatigue, sore throat, and trouble swallowing that had gone on for three months.

Testing of the pus revealed the likely culprit: a fungus called Chondrostereum purpureum, which causes a disease called silver leaf in plants. It usually infects plants and trees belonging to the rose family, including those responsible for making cherries and plums.

Although some microbes can occasionally jump from one species to another and cause illness, it is rare for plant pathogens to cross over into humans.

As far as the report authors know, this is the first report of human infection from C. purpureum. Although some fungi can regularly infect and make people sick, these infections tend to happen in people who are immunocompromised.

This particular case is even stranger since the man had a healthy immune system. The researchers speculate that the man’s job as a plant mycologist made him vulnerable to the infection since he worked with decaying plant material and other fungi in his research.

They hypothesize that he was exposed to the fungus enough times that it was somehow able to overcome the species barrier.

Luckily, the man was successfully treated and has shown no signs of a recurrent infection. However, the report authors note that the past few decades have seen a reported rise in human fungal pathogens, and some scientists even theorize that our warming climate is enabling some fungi to become better suited to humans.

If plant fungi can rarely cross over and infect people or other animals, that’s a discovery with important implications for the emergence of infectious diseases.

Therefore, much more research will have to be done to study the potential mechanisms involved in these “cross-kingdom” infections.