Mold in the News Series

Part 7: Common Plant Fungus Cross Species to Humans

Cesar Collado
Dec 29, 2023

Plant Fungus Cross-Species to Humans Can Present Global Emergencies

A recent case of a human being infected by a plant fungus has captured the attention of the world. This is a first of its kind of a case wherein this plant fungus, Silver Leaf Disease, caused disease in a human. Conventional techniques (microscopy and culture) failed to identify the fungus. Only by sequencing, the identity of this unusual pathogen could be revealed. This case highlights the potential of environmental plant fungi to cause disease in humans and stresses the importance of molecular techniques to identify the causative fungal species. [1]

Cross-Species Viral Infections Are Health Policy Concerns

Cross Species infections cause global health concerns. Disease such as the hantavirus, Haemorrhagic fever viruses, Arboviruses, Nipah and Hendra viruses, Avian Influenza Virus (AI), Monkeypox virus, Swine Flu, and the SARS‐associated coronavirus (SARS‐CoV) caused various levels of global emergencies. 

About Fungal infections

There are millions of fungal species; but only a few can naturally infect humans. Over the past several decades, multiple medical advances have rendered more people—especially the immunocompromised—susceptible to infections with fungi not previously considered pathogenic.

Very few fungal species meet the few basic conditions necessary to infect humans. [2]

  • A high temperature tolerance
  • The ability to invade the human host
  • Destruction and absorption of human tissue
  • Resistance to the human immune system.

In the past, invasive fungal disease was rare because human and animal immune systems are very sophisticated. They evolve in constant response to fungal challenges. In contrast, fungal diseases may occur more frequently in immunocompromised patients. The introduction of the HIV virus in the 80s put patients at risk for invasive fungal infections. 

Cross species infection

Fungal infections today are among the most difficult diseases to manage in humans. Few fungi cause disease in healthy people, but most fungal infections occur in individuals already experiencing serious illness. Fungal infections frequently jeopardize the success of the newest medical advances in cancer care, solid organ and hematopoietic stem cell transplantation, neonatal medicine, autoimmune disease therapies, trauma and intensive care, and sophisticated surgery. In fact, these medical advances themselves often make their beneficiaries vulnerable to fungal disease.

There are some fungal infections that are fairly common.  Vaginal yeast infections, thrush, and toenail infections are common, as is athlete’s foot. Many occur after a round of antibiotics is taken. The chronic ailments do not pose a life threat and treatments are available.  

Common fungal infections

Pathogenic Fungal Infections

It is important to note that the vast majority of plant-pathogenic fungi are not pathogenic to humans. Here are a few examples where there is some crossover:

  • Sporothrix schenckii: This fungus is commonly found in soil, plant matter, and on the thorns of plants. Humans can become infected with this fungus, leading to a condition known as sporotrichosis or “rose gardener’s disease”. Infection typically occurs when the fungal spores are introduced into the skin through minor cuts or punctures, such as from a thorn prick.
  • Aspergillus species: While some Aspergillus species are pathogenic to plants, others can infect humans, especially those with compromised immune systems. In humans, these fungi can cause a condition called aspergillosis, which affects the sinuses and respiratory system.
  • Fusarium species: Some Fusarium species, which can cause diseases in plants, have also been known to cause infections in humans, particularly in the eyes, leading to conditions like fungal keratitis.
  • Mucor and Rhizopus species: These are examples of fungi that can be found on decaying plant material and can also cause infections in humans, particularly in the form of mucormycosis.

Mucor Lung Infection

It’s important to note that the risk of infection by plant-pathogenic fungi in healthy individuals is relatively low. Individuals with weakened immune systems, certain underlying health conditions, or those who have experienced trauma or injuries are at a higher risk.  Read more on pathogenic mold HERE.

Good hygiene, proper wound care, and wearing protective gloves when gardening or handling soil and plant material can help reduce the risk of fungal infections. If someone suspects a fungal infection, they should seek medical attention promptly. Read about Getting a Grip on Mold.

The Plant Fungus Cross-Species Threat

Cross-species fungal infections refer to fungal diseases that have the capacity to infect multiple species. These types of infections can originate in one species and then spread to another, sometimes with varying levels of pathogenicity. Here are some key points to understand:

Zoonotic Fungi: These are fungi that can be transmitted from animals to humans. For example:

Coccidioides immitis and Coccidioides posadasii, responsible for coccidioidomycosis (Valley fever), primarily infect humans and certain animals.

  • Blastomyces dermatitidis, which causes blastomycosis, can infect both humans and dogs.
  • Environmental Sources: Some fungi exist in specific environments and can infect various species that come into contact with that environment.
  • Batrachochytrium dendrobatidis is responsible for chytridiomycosis in amphibians, leading to declines in amphibian populations worldwide. Although this fungus primarily affects amphibians, the concern is in its environmental persistence and the effect on biodiversity.
  • Adaptation and Evolution: Fungi can sometimes adapt to new hosts, which can lead to the emergence of new diseases. This is especially of concern if a fungal pathogen that typically affects plants or animals evolves the ability to infect humans.

Direct contact, inhalation of spores, and, less commonly, ingestion are typical routes of transmission for fungal pathogens. Fungal infections are generally not transmitted from person to person, with a few exceptions like some forms of skin infections (e.g., athlete’s foot).

Treatment varies depending on the specific fungus and the severity of the infection. Antifungal drugs, such as azoles (e.g., fluconazole) or amphotericin B, are commonly used. These medications have toxicity issues themselves.  As a result, physicians do not like to use them and must monitor the patient’s organ function closely.  Some fungal infections, especially those that become systemic, can be very challenging to treat and may require long-term therapy.

Climate change and global travel can facilitate the spread and emergence of fungal pathogens in new regions, potentially leading to plant fungus cross-species infections. For instance, Candida auris is an emerging multidrug-resistant fungal pathogen causing concern in healthcare settings worldwide.

Plant Fungus Cross-Species Conclusions

While many fungi are host-specific, several have the potential to infect multiple species, including humans. Understanding and monitoring these pathogens is crucial for both public health and conservation efforts. Special attention should be focused on plant fungus crossing species. Physicians and hospitals must be skilled in identifying fungal infections.  This includes patients believed to have bacterial infections.  In addition, diagnostic testing and an open mind by physicians and hospitals when encountering suspected fungal infections are necessary.

BioBalance provides multiple solutions to maintain a healthy balance of microorganisms and remove systemic fungi inside your home.  Read more about “Getting a Grip” on mold fogging HERE.

HavenFog is an intensive mold treatment.  HavenFog is a non-toxic, natural, citrus-based solution for safely treating mold in every nook & cranny of your home or office.  It produces a dense fog that entirely filles the air volume in a home to collide with, fracture the cell wall, and allow gravity to accumulate mold remains on the floor that can be effectively HEPA vacuumed.

HavenMist is a water-based maintenance mold treatment that is ideal for smaller jobs and routine mold maintenance.  It is a non-toxic, natural, citrus-based solution for safely maintaining your home or office from mold growth.  It can be administered very quickly, followed by a wipe down and vacuuming to remove mold remains.

Read more about a comprehensive small particulate cleanup protocol HERE.

Small Particulate Clean up

  1. Dutta, S.” Paratracheal absess by plant fungus chondrostereum purpureum-first case report in humans.”Medical Mycology Case Report. March, 2023.
  2. Köhler JR. et. al.“The spectrum of fungi that infects humans.” Cold Spring Harb Perspect Med. Nov 3, 2014
  3. Carpouron JE, et. Al. “Emerging Animal-Associated Fungal Diseases.” J Fungi (Basel). June 2022.



"Toxic Mold in the News" Series publishing weekly starting mid-November 2023.

Headline News

Toxic Mold in the News Part 1:

Mold in the News Series Introduction

November 17, 2023

Headline News

Toxic Mold in the News Part 2:

Fungal Infections Are a Growing Concern

November 24, 2023

Headline News

Toxic Mold in the News Part 3:

Candida Infections in the Brain

December 1, 2023

Headline News

Toxic Mold in the News Part 4:

Fungal Brain Infections

December 8, 2023

Headline News

Toxic Mold in the News Part 5:

The Link Between Mold Illness and Alzheimer’s

December 15, 2023

Headline News

Toxic Mold in the News Part 6:

2023 Fungal Meningitis Outbreak

December 22, 2023

Headline News

Toxic Mold in the News Part 7:

Common Plant Fungus Cross Species to Humans

December 29, 2023

Product Recalls

Toxic Mold in the News Part 8:

Product Recalls Due to Mold

January 5, 2023