London, Nov 28 (IANS): It's not just MRSA and E. coli, but scientists have identified another form of bacterium, present on the skin of every person, that is becoming increasingly dangerous due to antibiotic resistance.

The study showed that "Staphylococcus epidermidis" -- a close relative of MRSA -- is a major cause of life threatening infections after surgery but it is often overlooked by clinicians and scientists because it is so abundant.

"Staphlococcus epidermidis is a deadly pathogen in plain sight," said Sam Sheppard, Professor from the University of Bath in the UK.

"It has always been ignored clinically because it is frequently been assumed that it was a contaminant in lab samples or it was simply accepted as a known risk of surgery," he added.

The findings, published in the journal Nature Communications, showed that a small number of healthy individuals carry the more deadly form of the bacteria without knowing it.

Furthermore, the disease-causing genes help the bacterium grow in the bloodstream, avoid the host's immune response and made the cell surface sticky so that the organisms can form biofilms and make the bacterium resistant to antibiotics, the researchers noted.

For the study, the team identified a set of 61 genes that allow this normally harmless skin bacterium to cause life threatening illness.

The team took samples from patients who suffered infections following hip or knee joint replacement and fracture fixation operations and compared them with swab samples from the skin of healthy volunteers.

They compared the genetic variation in the whole genomes of bacteria found in samples from diseased and healthy individuals and identified 61 genes in the bacteria that were not present in most of the healthy samples.

Since the bug is so abundant, it can evolve very fast by swapping genes with each other.

If done nothing to control this, there is a risk that these disease-causing genes could spread more widely, meaning post-operative infections that are resistant to antibiotics could become even more common, the researchers warned.

Identifying people at high risk of infection can help doctors target them with extra hygiene precautions before they undergo surgery, they said.