Microbe of the Month: Pseudomonas

Classification Type: Bacteria

Cultured from / Found in HVAC: Coiling Coils, Diffusers, Grilles, Filters, Drain Pans, Humidifiers

Noted Health Risks:

Respiratory Infections, UTIs, Tissue Infections, Sepsis

 

About Pseudomonas

The bacteria are found widely in the environment, such as in soil, water, and plants. Pseudomonas infections are diseases caused by a bacterium from the genus Pseudomonas. More severe infections occur in people who are already hospitalised with another illness or condition, or people who have a weak immune system.

Hospitals are very susceptible to this bacterium, so are homes and all HVAC systems. When room temperature air cycles through an HVAC system and through the coil, condensation develops, and this moisture makes the area a prime breeding ground for bacteria and viruses. As the system operates these pathogens become airborne and travel into the rooms, looking for a new host (us) to infect.

Pseudomonas in HVAC systems create a microbial biofilm on heat exchanger surfaces causing flow restrictions, creating a decrease in efficiency, an increase in down time with the additional cleaning and repair costs. Preventing biofilm from forming in the first place is essential to an efficient HVAC system.

The CDC states that 4 patients out of every 1,000 who are discharged from a hospital become infected by Pseudomonas aeruginosa. One of the best known ways to kill bacteria, viruses and mould which make the HVAC evaporator coil their home is to use high powered UV lights with a wavelength of 253.7 to 254 nanometers (the UVC band). This germicidal wavelength of light is extremely deadly to pathogens growing in drip pans, on the coils, and even in the cycling air. UVC lights can reduce, if not eliminate, the risk of this bacteria spreading, along with a host of others.

Pseudomonas bacteremia refers to the presence of Pseudomonas bacteria in the bloodstream, often resulting from a primary infection at another site. Bacteremia can lead to sepsis, a life-threatening condition characterised by a dysregulated inflammatory response and organ dysfunction.

Health Risks

While many species of Pseudomonas are harmless, certain strains can pose significant health risks, particularly in individuals with weakened immune systems or underlying medical conditions. Here’s some of the health risks associated with Pseudomonas infections, their causes, symptoms, and potential consequences.

1. Pseudomonas Infections and Vulnerable Individuals

Pseudomonas infections typically occur through contact with contaminated water, soil, or medical equipment. Individuals with compromised immune systems, such as those with HIV/AIDS, cancer, diabetes, or chronic lung diseases, are more susceptible to infections. Moreover, hospital-acquired infections caused by Pseudomonas species, particularly Pseudomonas aeruginosa, are a significant concern, given the organism's ability to develop resistance to multiple antibiotics.

2. Respiratory Infections

Pseudomonas aeruginosa is a leading cause of respiratory tract infections, especially in individuals with cystic fibrosis (CF). CF patients have a higher risk of chronic lung infections due to the thick, sticky mucus that obstructs airways and facilitates bacterial colonisation. Pseudomonas aeruginosa can establish persistent infections in the lungs of CF patients, leading to progressive lung damage and decreased lung function if left untreated.

3. Urinary Tract Infections

Pseudomonas aeruginosa and other Pseudomonas species can also cause urinary tract infections (UTIs). These infections are commonly associated with the use of urinary catheters, which provide a pathway for bacteria to enter the urinary system. Symptoms of Pseudomonas UTIs may include pain or burning during urination, frequent urination, cloudy or foul-smelling urine, and pelvic discomfort. If left untreated, the infection can spread to the kidneys, leading to a more severe condition known as pyelonephritis.

4. Skin and Soft Tissue Infections

Pseudomonas aeruginosa is notorious for causing skin and soft tissue infections, particularly in individuals with burns, surgical wounds, or compromised skin integrity. These infections can manifest as cellulitis, folliculitis, ecthyma gangrenosum, or hot tub folliculitis. Symptoms include redness, swelling, pain, and the formation of pus-filled blisters. Prompt medical attention is crucial to prevent complications and systemic spread of the infection.

5. Bacteremia and Sepsis

Pseudomonas bacteremia refers to the presence of Pseudomonas bacteria in the bloodstream, often resulting from a primary infection at another site. Bacteremia can lead to sepsis, a life-threatening condition characterised by a dysregulated inflammatory response and organ dysfunction. Pseudomonas-associated sepsis has a higher mortality rate compared to other bacterial infections, primarily due to the organism's ability to resist multiple antibiotics.


References:

Breidenstein EBM, de la Fuente-Núñez C, Hancock REW. Pseudomonas aeruginosa: All Roads Lead to Resistance. Trends Microbiol. 2011 Aug;19(8):419-26. doi: 10.1016/j.tim.2011.04.005.

Ciofu O, Tolker-Nielsen T. Tolerance and Resistance of Pseudomonas aeruginosa Biofilms to Antimicrobial Agents-How P. aeruginosa Can Escape Antibiotics. Front Microbiol. 2019 Jan 8;10:913. doi: 10.


Safe indoor air from a serviced HVAC system means a lower particle count and less breathing difficulties for occupants of the building. Clean-Air are IICRC mould remediation experts with the knowledge and experience to test, treat and eliminate serious mould-related risks within your HVAC system. If you have concerns about the air you are breathing, or would like an HVAC health check, contact our team today.