bacterial contamination. conceptual computer artwork of a human hand contaminated with colonies of bacteria (blue/pink patches) and rod-shaped e. coli. the lurid colours represent the danger posed by the bacteria. hands come into contact with a wide variety of surfaces, and can transmit bacteria to and between the eyes, nose and mouth. common sources of particularly pathogenic bacteria are raw meat, vegetables and faeces. hand washing with soap and water can prevent most cases of disease transmission by hand contamination. if hands are not washed, the bacteria will quickly multiply into colonies many millions strong,. bacterial contamination. conceptual computer artwork of a human hand contaminated with colonies of bacteria (blue pink patches) and rod-shaped e. coli. the lurid colours represent the danger posed by the bacteria. hands come into contact with a wide variety of surfaces, and can transmit bacteria to and between the eyes, nose and mouth. common sources of particularly pathogenic bacteria are raw meat, vegetables and faeces. hand washing with soap and water can prevent most cases of disease transmission by hand contamination. if hands are not washed, the bacteria will quickly multiply into colonies many millions strong.