Biofilms and Materials' Infectivity

COVID-19 problems have caused people's concern about infection so far 3 . Generally, infections are spread from human to human. However, another route for the spread of infections should also be considered. It is "human-materials-human" infection. This means that the infection spreads through materials between humans. Therefore, biofilms formed on materials must play an important role. Biofilms form at interfaces such as the ones between gas-solid, gas-liquid, and liquid-solid. Particularly, those on solid materials in aqueous and gas environments are important. They are related to and cause problems for industry and our daily lives. As for bacteria, they can survive in biofilms with characteristics different from those in the planktonic form. For example, they have high resistance to antibiotics due to many reasons. Therefore, bacteria in biofilms could cause chronic infections through materials. On the other hand, viral activities generally change, depending on the material involved. Even though a lot of evidence do not exist for this relationship with biofilms, they seem to change the viral environments on materials in very complicated ways. In this chapter, we introduce the meaning of infections in the light of biofilms on materials. Also, we discuss quantitative evaluation methods, and the available countermeasures for the future. 4