Analysis of growth and biofilm formation of bacterial pathogens on frequently used spinal implant materials

A microscopy-based investigation of the permissive factors leading towards bacterial adherence on commonly utilized spinal implants. The adherence and subsequent colonization and biofilm formation of bacteria on orthopaedic implants represents one of the most serious problems facing orthopaedic surgeons. Once a biofilm is formed, surgeons may have to resort to implant removal, a strategy that may cause substantial patient morbidity and lead to additional cost to the healthcare system. This problem has been further compounded by the rise of antibiotic-resistant strains of bacterial pathogens. In this study, two commonly encountered bacterial pathogens in surgical site infections (SSI) were characterized for adherence pattern, density, and propagation on five commonly used spinal implant materials via scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The results show that bacterial adherence is largely dependent on the microtopographical features observed on the surface of the materials tested. Five commonly utilized spinal implant materials were inoculated with two of the most common nosocomial pathogens and visualized via scanning electron microscopy and confocal laser scanning microscopy. Analysis of 90 spinal implant pieces showed that even though no material showed the ability to prevent adherence of both pathogens tested, the presence of surface imperfections and rougher microtopography was found to harbor the most bacterial presence. Our data suggests that implants materials with uniform surface and minimal imperfections may reduce the ability of bacterial to adhere to implants. Level I evidence: “Investigation of a diagnostic test”.