Microbe of the Month: Staphylococcus

Classification Type: Bacteria

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

Noted Health Risks: Bloodstream Infections, Pneumonia, Bone and Joint Infections.

Staphylococcus aureus is a round-shaped bacterium, a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. Infections caused by this pathogen are common both in community-acquired and hospital-acquired settings. The treatment remains challenging due to the emergence of multi-drug resistant strains such as MRSA (Methicillin-Resistant Staphylococcus aureus). It’s an opportunistic pathogen, associated with soft-tissue infections commonly encountered within indoor environments as a component of airborne dust deposited in the respiratory tracts of occupants. S. aureus does not normally cause infection on healthy skin, however, if it is allowed to enter the internal tissues or bloodstream, these bacteria may cause a variety of serious infections.

Often referred to as "deep" infections, Staphylococcus aureus can circulate through the bloodstream reaching bone, joint, or muscle. Children are especially vulnerable to this type of infection.

Health Risks

Here are some health risks associated with Staphylococcus:

  1. Skin Infections: Staphylococcus aureus can cause a wide range of skin infections, including boils, impetigo, cellulitis, and folliculitis. These infections are often characterized by redness, swelling, pain, and the presence of pus-filled lesions. [1] [2]
  2. Wound Infections: Staphylococcus aureus is a common cause of wound infections, especially in healthcare settings. Surgical wounds, puncture wounds, and traumatic injuries can become infected with Staphylococcus, leading to delayed healing, increased pain, and potential complications. [3]
  3. Toxic Shock Syndrome (TSS): Staphylococcal toxic shock syndrome is a rare but serious condition caused by certain strains of Staphylococcus aureus. It is characterized by a sudden onset of high fever, rash, low blood pressure, and organ dysfunction. TSS can be life-threatening and requires immediate medical attention. [4] [5]
  4. Respiratory Infections: Staphylococcus aureus can cause respiratory tract infections, such as pneumonia and sinusitis. These infections can range from mild to severe and may be particularly problematic in individuals with weakened immune systems. [6] [7]
  5. Bloodstream Infections: Staphylococcus aureus can enter the bloodstream through wounds, medical devices, or surgical procedures, leading to bloodstream infections or sepsis. These infections can be difficult to treat and may have high morbidity and mortality rates, especially when caused by antibiotic-resistant strains like methicillin-resistant Staphylococcus aureus (MRSA). [8] [9]
  6. Food Poisoning: Certain strains of Staphylococcus aureus can produce heat-stable toxins that can cause food poisoning when contaminated food is consumed. Symptoms include rapid onset of nausea, vomiting, abdominal cramps, and diarrhea. Most cases are self-limiting and resolve within a few days. [10]
  7. Bone and Joint Infections: Staphylococcus circulate through the bloodstream until they reach a bone, joint, or muscle and multiply. Unfortunately, children are especially vulnerable to this type of infection. Often referred to as "deep" infections, the technical names for these conditions are: Osteomyelitis (bone infection), Septic arthritis (joint infection), Pyomyositis (muscle infection), Abscess (isolated pocket of infection, with pus, typically in soft tissues). [11]

It's important to note that Staphylococcus infections can vary in severity, and the specific health risks may depend on various factors, including the strain of the bacteria, the site of infection, and the individual's overall health.


[1] Staphylococcus aureus Infections. (2020). Centers for Disease Control and Prevention. Retrieved from https://www.cdc.gov/hai/organisms/staph.html [2] Tong, S. Y. C., Davis, J. S., Eichenberger, E., Holland, T. L., & Fowler, V. G. (2015). Staphylococcus aureus Infections: Epidemiology, Pathophysiology, Clinical Manifestations, and Management. Clinical Microbiology Reviews, 28(3), 603–661. doi: 10.1128/cmr.00134-14 [3] Wound Infections. (2019). Merck Manual Professional Version. Retrieved from https://www.merckmanuals.com/professional/infectious-diseases/gram [4] Staphylococcal Toxic Shock Syndrome. (2019). Merck Manual Professional Version. Retrieved from https://www.merckmanuals.com/professional/infectious-diseases/gram-positive-cocci/staphylococcal-toxic-shock-syndrome [5]Toxic Shock Syndrome. (2020). Centers for Disease Control and Prevention. Retrieved from https://www.cdc.gov/groupastrep/diseases-public/toxic-shock-syndrome.html [6]Staphylococcus aureus Infections of the Respiratory Tract. (2019). Merck Manual Professional Version. Retrieved from https://www.merckmanuals.com/professional/infectious-diseases/gram-positive-cocci/staphylococcus-aureus-infections-of-the-respiratory-tract [7]Sinusitis. (2021). Mayo Clinic. Retrieved from https://www.mayoclinic.org/diseases-conditions/sinusitis/symptoms-causes/syc-20377516 [8]Bloodstream Infections. (2019). Merck Manual Professional Version. Retrieved from https://www.merckmanuals.com/professional/infectious-diseases/gram-positive-cocci/bloodstream-infections [9]Septicemia. (2021). Mayo Clinic. Retrieved from https://www.mayoclinic.org/diseases-conditions/sepsis/symptoms-causes/syc-20351214 [10]Food Poisoning. (2019). Merck Manual Consumer Version. Retrieved from https://www.merckmanuals.com/home/infections/food-poisoning/food-poisoning [11] https://orthoinfo.aaos.org/en/diseases--conditions/bone-joint-and-muscle-infections-in-children/

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.