High percentage of microbial colonization of osteosynthesis material in clinically unremarkable patients

Stabilization of fractures with internal fixation devices is a common procedure and implant‐associated infections are a dreaded complication. The exact pathomechanism is not completely understood; however, microbial colonization of osteosynthesis material is considered a trigger for infection. This study aimed to determine the colonization rate of osteosynthesis implants in patients with no clinical or laboratory signs of infection, using two methods, conventional culture and polymerase chain reaction (PCR) of sonication fluid. Fifty‐seven patients aged between 18 and 79 years without signs of infection who underwent routine removal of osteosynthesis devices between March 2015 and May 2017 were included in this study. Osteosynthesis material was investigated by sonication followed by cultivation of the sonication fluid in blood culture bottles and PCR analysis, simultaneously. Additionally, electron scanning microscopy was performed in nine representative implants to evaluate biofilm production. Thirty‐two (56.1%) implants showed a positive result either by culture or PCR with coagulase‐negative staphylococci being the most commonly identified microorganism (68.1%). Furthermore, the detection rate of the culture (50.9%) was significantly higher compared to PCR (21.1%). The scanning electron microscopy imaging demonstrated biofilm‐like structures in four of six culture and/or PCR‐positive samples. This study is the first, to the best of our knowledge, to demonstrate bacterial colonization of osteosynthesis implants in healthy patients with no clinical or laboratory signs of infection. Colonization rate was unexpectedly high and conventional culture was superior to PCR in microbial detection. The common understanding that colonization is a trigger for infection underlines the need for strategies to prevent colonization of implant material like antibiotic‐loaded coating or intraoperative gel application.

A novel method for the removal of epoxy coating from waste printed circuit board

The printed circuit board, which is the heart of all electronic devices, is a rich source of metal, which could act as a future resource. Bioleaching, a biological treatment, would be an appropriate method for the environmentally sound management of e-waste. Various strippers are used to remove the epoxy coating and it is harmful to remove the epoxy coating with those solvents and salts in the open because of the presence of brominated flame retardants on the surface of the printed circuit board, which leads to serious health issues. An alternate process is required to remove the epoxy coating thereby enhancing the bioleaching process. Sonication is the process of applying sound energy to agitate particles in a solvent bath. The combined process of sonication and solvent stripping in a closed environment could decrease the time for stripping the epoxy coating. An attempt has been made to optimise the stripping agent for the removal of epoxy coating and from the experiment it was found that bath sonication could easily remove the epoxy coating from the waste printed circuit board with no emission of toxic gases. An optimum time of 5 min was enough for the stripping process prior to the soak time of 8 h at 5 N NaOH solution, while a longer time and high concentration of chemicals would be required to remove the epoxy coating with usual methods.