Bacteria found on mobile phone, conceptual computer illustration. With frequent use cell phones remain warm, creating the ideal breeding ground for microorganisms. With touch-screen phones, the same part of the phone touched with fingertips is pressed up against the face and mouth, increasing chances of infection. In tests E. coli, Haemophilus influenzae and MRSA were amongst infectious bacteria found on handsets. Common harmless bacteria include Staphylococcus epidermidis, Micrococcus, Streptococcus viridans, Moraxella, and bacillus species.