Modern mobile phones are with us constantly, moving between our pockets and bag, at home and work. A university experiment reveals they are constantly picking up bacteria, retaining a history of our actions.

To find out exactly how much bacteria mobile phones contain, students at the University of Surrey imprinted their phones onto bacterial growth material in Petri dishes and left them to develop.

Within three days the bacteria was visible with rather grim results.

White bacteria

The students are studying Practical and Biomedical Bacteriology led by senior lecturer Dr Simon Park.

Although most of the bacteria were harmless, Staphylococcus aureus, bacteria that can cause skin infections was found: “The ecological niche on the body for Staphylococcus aureus is the nostrils, so a furtive pick of the nose, and quick text after, and you end up with this pathogen on your smartphone” said Dr Park.

Brown bacteria

According to Dr Park the bacteria on your phone provides a footprint of your daily life, for instance a type of bacteria called Baccillusmycoides was found which is typically found in soil indicating the person or its phone had been in contact with soil.

Bacteria in outline of phone

“It seems that the mobile phone doesn’t just remember telephone numbers, but also harbours a history of our personal and physical contacts such as other people, soil and other matter” said Dr Park”

Photo credit: University of Surrey