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.

Combined effect of attrition and ultrasound on the disruption of Pseudomonas putida for the efficient release of arginine deiminase.

Disruption of Pseudomonas putida KT2440 by ultrasound treatment in a bath sonicator, in presence of the glass beads, was carried out for the release of arginine deiminase (ADI) and the results were compared with that of by Dyno-mill. The release of ADI depended mainly on the bead size and cellmass concentration being disrupted in bead mill. Nearly 23 U mL-1 ADI was released when slurry with a cell-mass concentration of 250 g L-1 was disintegrated for 9 min with 80% bead loading (0.25 mm) in Dyno-mill. Marginally higher amount of ADI (24.1 U mL-1 ) was released by the bath sonication of 250 g L-1 cellmass slurry for 30 min with the beads (0.1 mm) and a sonication power of 170 W. The glass beads, suspended along with the cellmass slurry in bath sonicator, efficiently disrupted the microbial cells to release ADI. Variation in the kinetic constants for the performance parameters implied that ADI release and cell disruption kinetics is a function of disruption technique used and the process variables thereof. Estimation of location factor suggested that selective release of ADI can be achieved. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018 © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1185-1194, 2018.

AgBr and AgCl nanoparticle doped TEMPO-oxidized microfiber cellulose as a starting material for antimicrobial filter.

Present work covers the state-of-art progress in the advanced nanoarchitecture of organic-inorganic hybrid material; a starting material for the antimicrobial filter. TEMPO-mediated oxidation of microfiber cellulose was carried out to introduce the surface active carboxyl groups. Accordingly, qualitative and quantitative substitution of a functional group was investigated using FTIR, Solid state 13C CP/MAS NMR, and potentiometric titration; the reaction resulted to about 21.06% increase in carboxylate content. Further, the microwave irradiated (600 W) in-situ synthesis of AgBr and AgCl nanocubes were prepared and doped on carboxylated microfiber. The prepared AgBr@TO-MF and AgCl@TO-MF were tested using XRD, XPS, SEM and FTIR. With an average size of AgBr and AgCl nanocubes of around 200 ±â€¯28 nm and 116 ±â€¯10.73 nm. Whereas, AgBr@TO-MF and AgCl@TO-MF shown excellent antimicrobial activity against E. Coli and B. Subtilis, with MIC at around 200 µg/mL and 150 µg/mL, respectively. Fascinatingly, ICP-OES analysis estimated the silver leached was around 0.1 ppm.

Cell disruption using a different methodology for proteomics analysis of Trypanosoma cruzi strains.

We have developed a cell disruption method to produce a protein extract using Trypanosoma cruzi cells based on a straightforward hypoosmotic lysis protocol. The procedure consists of three steps: incubation of the cells in a hypoosmotic lysis buffer, sonication in a water bath, and centrifugation. The final protein extract was designated TcS12. The stages of cell disruption at different incubation times were monitored by differential interference contrast microscopy. After 30min of incubation in lysis buffer at 4°C, the T. cruzi epimastigote forms changed from slender to round-shaped parasites. Nevertheless, cell disruption took place following sonication of the sample for 30min. The efficiency of the methodology was also validated by flow cytometry, which resulted in 72% of propidium iodide (PI)-labeled cells. To estimate the protein extraction yield and the differential protein expression, the proteomics profile of four T. cruzi strains (CL-Brener, Dm28c, Y, and 4167) were analyzed by liquid chromatography tandem mass spectrometry (LCMS/MS) on a SYNAPT HDMS system using the label-free MS(E) approach. ProteinLynx Global Server (version 2.5) with Expression(E) analysis identified a total of 1153 proteins and revealed 428 differentially expressed proteins among the strains. Gene ontology analysis showed that not only cytosolic proteins but also nuclear and organellar ones were present in the extract.