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Mold Blindspots Series

Part 3: What is Microbial Soup?

October 5, 2023

Microbial Contamination in Water Damaged Homes

By Cesar Collado

Microbial Soup refers to the common coexistence and synergies of mold, bacteria, and viruses in water damaged homes.  My previous article in this series described the conditions that promote the coexistence of multiple microbial species.  This article describes some mold and bacterial combinations that are commonly encountered. In these cases, several fungi and bacteria combinations are found together, which can contribute to indoor air quality issues and potential health concerns.  As a result, these issues and concerns can then lead to medical consequences and unique hardships encountered by those who are mold sensitive.

Biofilms have become increasingly referenced by medical professionals when addressing microbial infections. Biofilms can form in crevices or “craters” in tissue walls. This is often recognized in cases of chronic sinusitis. The precision and close proximity of endoscopic cameras and tools make this possible. Biofilms are also regularly found in the gut where they wreak havoc on the digestive system.  As a result, biofilms can form inside and outside the body and exposure can occur at any time.

Biofilm formation

Biofilm Formation in Our Bodies

When a foreign antigen enters the body, our body’s protection system will have an immediate reaction.  When this occurs, eosinophils will attack immediately and can create some collateral damage in tissues.  Consequently, bacteria and fungi can hide in these crevices.  Biofilms are formations of a surface matrix that joins and protects the multiple microbes including bacteria and fungi.  With the recognition of biofilms, professionals can explain the presence of the endotoxins that can cause a superantigen response.

biofilm formation

Examples of Microbial Combinations That Occur

  1. Aspergillus and Pseudomonas:

    Aspergillus is a genus of fungi commonly found in water-damaged environments. Some species of Aspergillus can produce mycotoxins that can cause severe illness. Pseudomonas is a group of bacteria that can thrive in moist conditions. In water-damaged homes, the presence of Aspergillus and Pseudomonas together can cause risk for respiratory issues and fungal infections.

  2. Stachybotrys and Streptomyces:

    Stachybotrys chartarum, often referred to as black mold, is one of the toxic molds associated with water damage. It is known for producing mycotoxins and is often a health concern.  Streptomyces, a genus of bacteria commonly found in soil and decaying plant material, is often present in water-damaged environments. The combination of Stachybotrys and Streptomyces worsens indoor air quality and potentially causes severe respiratory symptoms.


  3. Penicillium and Bacillus:

    Penicillium is a common fungus found in water-damaged buildings. However, some penicillium species produce mycotoxins. Bacillus, a group of bacteria, is also often present in water-damaged environments. In particular, it is found in areas with high organic content. As a result, the presence of Penicillium and Bacillus together in building materials can contribute to indoor air quality issues and potential respiratory health effects.


  4. Alternaria and Enterobacter:

    Alternaria is another genus of fungi commonly found in water-damaged buildings. Therefore, it can act as an antigen, produce mycotoxins and inflammation in sensitive individuals. As a result, asthma like symptoms might occur in occupants. Enterobacter, a group of bacteria, is often associated with water damaged building materials and can thrive in damp environments. The combination of Alternaria and Enterobacter can worsen indoor air quality and pose a risk to respiratory health.

Water Damage Creates a Dynamic Environment with Many Variables

Specific combinations of fungi and bacteria in water-damaged homes will vary, depending on environmental conditions.  Poor environmental conditions include the extent and duration of water damage and the presence of organic materials or food.  However, you can address water damage and mitigate the associated microbial risks effectively with the help of professionals.  DIY testing in advance will help facilitate the inspection process.  Try testing with mold test plates to provide an analysis that will identify more mold species and combinations than PCR analysis.


Single microbial infestation is unlikely for water damaged homes.  The presence of moisture with common building materials can be associated with many combinations of microorganisms. When the source of moisture comes from flooding or leaking, Microbial Soup should be the expectation.  Using ImmunoLytics Mold Test Plates, you will be able to visually examine the diversity of the mold species cultured from your samples. You will likely find these combinations and countless others on occasion.  This information can be helpful when determining your remediation plan, if tests are positive.

Multiple Organisms Coexisting

Lab professionals at ImmunoLytics are trained to identify common fungal and bacterial contaminants while analyzing mold test plates.

Lab microscopy


Mold Blind Spots Series

This article series sheds light on often overlooked mold sensitivity triggers or mold blind spots. Look for our weekly published articles beginning mid-September 2023.

Mold Blind Spot 1:

The Superantigen Response to Mold

There are certain situations where mold induces a cytokine storm.  A cytokine storm is an intense inflammatory reaction that can lead to life-threatening conditions. The immune system goes into overdrive in producing inflammatory signals called cytokines.  This condition is difficult to diagnose and is often misdiagnosed in emergency settings.

Mold test Plates
Mold Blind Spot 2:

Microbial Coexistence

Most infectious conditions involve multiple microbial contaminations.  Single organism infections do occur in various environments. However, single fungal microorganism contamination is a rare phenomenon unless the specific mold has colonized and reproduced significantly in part of the human body.

Microbial soup
Mold Blind Spot 3:

What is Microbial Soup?

October 5, 2023

In most infection cases, biofilms are formed collaboratively by different microorganisms in order to mutually survive in the body. There are many common microbial combinations that are prevalent in water-damaged homes.

Hospital infections
Mold Blind Spot 4:

Hospital Acquired Infections

October 12, 2023

While hospitals would seem to be well maintained and regularly disinfected, many people develop infections after being in the hospital for a couple days.  The “nosocomial” infections are prevalent, often resistant, and can be life threatening.

Mold Blind Spot 5:

Vulnerable Populations

November 2, 2023

The presence of mold can pose significant health risks for immunocompromised individuals. Explore the unique health circumstances that impact a family’s well-being.

Mold test Plates
Mold Blind Spot 6:

Aspergillosis, A Common Fungal Infection

November 9, 2023

Aspergillus is the most common fungal infection that often involves hospitalizations. Aspergillosis infections involve significant reproduction and colonization inside the human body. Aspergillus is also a mycotoxin producing mold. It is helpful to understand fungal infections and the impact on health and potential treatment approaches.

Mold Blind Spot 7:

Candida Overgrowth

November 16, 2023

Candida albicans are single cell yeasts that are part of the fungi empire and also a component of the human microbiome. Candida overgrowth, often linked to diet and antibiotic usage, can have significant chronic and acute health implications.

Mold test Plates
Mold Blind Spot 8:

Understanding "The Body’s Toxic Load"

November 22, 2023

The human body is limited in it’s ability to process toxic substances like pollutants, heavy metals, and more. Learn how mold illness can result from single severe exposure, or cumulative minor ones, leading to severe mold sensitivity. The body’s “toxic load” is referenced when the body has reached its lifetime maximum of toxins and becomes hypersensitive to almost any allergen or toxin.