Post-operative infections, the main cause could be skin bacteria

According to a study reported by NewScientist and conducted on just over 200 people undergoing spinal procedures, the Post-operative surgical infections could be caused mainly by bacteria that already live on the skin rather than from external contamination. In fact, hospitals tend to have rigorous hygiene standards, including the sterilization of clothing and surgical instruments to avoid these types of complications. However, second an American study, approximately 3% of people who undergo surgery experience an infection after the operation. The European CDC data relating only to patients hospitalized in intensive care in 2020 (the year of Covid) is disturbing: 12.7% of them contracted an infection.

The skin microbiome and infections

The hypothesis that many post-operative infections could arise from the skin microbiome of an individual was investigated by a group of scientists from the University of Washington in Seattle led by Dusting Long, anesthesiologist and specialist in intensive care medicine. The working group gathered skin swabs before and after spinal surgery of 204 patients. Fourteen people developed wound infections. After analyzing the responsible microbiomes, the team discovered that 12 of the cases involved bacteria that were already part of the skin microbiome of patients already before surgery. “Virtually almost all surgical site infections we encountered came from the patient's microbiome and not from pathogens introduced from the hospital or operating room,” explained Stephen Salipante, one of the authors of the study. Researchers expect similar results for any surgery that involves an incision in the skin.

Organisms resistant to antibiotics

The researchers also highlighted that 59% of organisms that cause infections discovered during the study were resistant to antibiotics administered before surgery with the aim of blocking infections. «By discovering antibiotic resistance traits in the microbiome before surgery, it would be possible to adapt antibiotic therapy to each individual patient to make it as effective as possible» adds Salipante. In the future it could be very useful to discover the most effective methods for sterilizing people's skin before an operation.

The importance of hygiene in a hospital environment

“Despite the results, a clean hospital environment with sterile instruments is essential,” comments Long. Intubations and catheters are in fact the procedures most at risk of infection. Intensive care units are the hospital departments with the highest prevalence of infections given that they use invasive devices (such as endotracheal tubes and vascular and urinary catheters) and host patients in serious conditions with associated massive use of antibiotics. Hygiene and handwashing of healthcare workers remain crucial.