There is a link between the microbial communities that are on human skin and the indoor environment.

The indoor environment is teeming with microbial life. 

But there is a reduction in the diversity of microbial life indoors when compared to the external environment. 

That reduction may be linked to an increase in diseases such as asthma and allergies. 

The microorganisms that inhabit hospitals may influence patient recovery and outcome depending on the pathogen.

The microbes that are present in hospitals may lead to hospital-acquired infections in patients, which is a factor in patient’s death, especially in immune-compromised patients.

A new study in *Science Translational Medicine* has found that in the first few hours of a hospital stay, the microbes living on the walls and other surfaces of the hospital try to overwhelm the microbes on the skin of patients in the room.

Then within 24 hours, the patient’s microbes overthrow the microbes present in the hospital room.

The researchers tracked the microbial life in a new hospital over the course of a year.

They started their research before the hospital opened and continued the study when it was full of patients.

The research was looking to understand the microbial dynamics that occur in a hospital.

What they wanted to investigate was whether surface sprays and wall treatments of beneficial microbes would reduce deadly pathogens and prime the immune systems of patients.

Patients and staff were swabbed as well as hospital fixtures.

Bed rails, walls, floors, chairs, phones, faucets, air filters, computer mice, shoes, and countertops were all swabbed.

They also tracked the temperature, humidity and lighting in the hospital’s rooms.

The microbes in patient rooms, particularly on bedrails, consistently resembled the microbes on the skin of the patient occupying the room.

The communities of bacteria on patients and room surfaces become increasingly similar over the course of the patient’s stay.

There was little effect upon microbes on the patient’s skin despite being treated with intravenous or oral antibiotics.

The one exception was the use of topical antibiotics, which did reduce the skin’s microbial population.

The microbes on the hands of staff were similar to the populations on their pagers and phones.

And unsurprisingly, the microbes on bed rails mirrored the microbes on patient’s hands.

Hospital staff were more likely to be a source of bacteria on the skin of patients.

When nurses attend to a patient, they drop off microbes from their clothing which has an effect upon the patient’s microbial balance.

But because nurses are likely to wear gloves and masks, they do not experience an exchange of microbes like the patient does.

But the study found that there was no universal patterns of transmission across the hospital.

When there are other patients in a room, they exchange microbes back and forth with themselves.

One other factor that can affect the microbial balance in a room is whether it is humid or warmer.

In warmer conditions, the similarity between the microbes of patients and their rooms is reduced.

But if it is humid, the patient’s microbes and the rooms become more similar.

Before the hospital opened, Acinetobacter and Pseudomonas were the most common microbes.

Once opened, the hospital environment changes to Corynebacterium, Staphylococcus, and Streptococcus.

The authors said

*”When patients enter a hospital, they arrive with complex and dynamic microbial assemblages that will be shaped by the treatment they receive and by the interactions they have with staff and with the building itself. As the influence of human microbial ecology on patient care and recovery in the hospital environment becomes better understood, being able to reinforce beneficial microbial interactions and mitigate harmful ones throughout the course of hospitalization will become paramount.”*

To learn more about microbial life:

Lax, Simon, et al. “Bacterial colonization and succession in a newly opened hospital.” Science Translational Medicine 9.391 (2017): eaah6500.