Development of microbial biofilms on biomaterials used in medicine
The adherence of pathogens on the surface of susceptible cells/inert supports is mediated by microbial structures called adhesins, with a great structural and biochemical diversity (Lazar, 2003). MDs are used in almost all diagnostic and therapeutic medical procedures, and depending on their specific application, they are composed of different materials such as, polymeric, metallic, or ceramic ones (Frederick, 1994). The MD that are used in the internal medium or are partially in contact with the tissues of the human body must meet a series of criteria, such as biocompatibility, strength, and stability, in relation with tissues, enzymes, cells, and various body fluids (Kaali et al., 2011). If the host-body tissues do not perfectly adhere to the biomaterial surface, there occur conditions that are favorable for microbial adherence, and hence for the formation of microbial biofilms. Therefore, one could state that biocompatibility is inversely related with the microbial adherence capacity (Lazar, 2003). In the past 20 years it was found that 6-14% of the hospitalized patients develop nosocomial infections that are in general associated with internal or partial internal MDs (invasive MDs), such as tracheal prostheses, pacemakers, endotracheal tubes, urinary catheters, peritoneal dialysis catheters, contact lenses, dental implants, orthopedic implants, surgical soft tissue prostheses, and so on (Sousa et al., 2011).