Reduction of the neutralisation time during antimicrobial activity testing of disinfectants according to European standards

Background. Evaluation of the biocidal activity of chemical disinfectants and antiseptics according to European Standards (EN) is based on determination of the reduction of the number of viable test microorganisms under defined conditions. Objective. The objective of this study was to investigate whether reducing the neutralization time required following declared product contact times for the tested microorganisms yields method validations. Material and methods. This study was conducted on 14 products containing active substances from different chemical groups: alcohols, aldehydes, biguanides, quaternary ammonium compounds, phenols, amines derivatives, oxidizing agents. These products were tested according to phase 1 tests: EN 1040:2005 and EN 1275:2005 and then according to phase 2, step 1 tests: Draft EN 13727:2005 and EN 13624:2003. Biocidal activity was evaluated using the following test organisms: S. aureus ATCC 6538, P. aeruginosa ATCC 15442, E. coli NCTC 10538, E. coli ATCC 10536, E. hirae ATCC 10541, C. albicans ATCC 10231 and A. brasiliensis ATCC 16404. Results. Validation C results for all products and tested microorganism strains were at least half of the density of the suspension for validation (Nvo) after only 10 s of neutralization. Furthermore, results from test procedures performed in parallel were also positive except 5 products toward A. brasiliensis. Conclusions. The results of our study confirm that the contact time described in the European Standards phase 1: EN 1040 and EN 1275, as well as phase 2, step 1: Draft EN 13727 and EN 13624 can be precisely determined in spite of reducing the neutralization time from 5 minutes to even 10 seconds.Wprowadzenie. Badanie aktywności antyseptyków wg norm PN-EN polega na określeniu stopnia redukcji liczby komórek drobnoustrojów testowych, uzyskanego w deklarowanym czasie kontaktu. Cel badań. Celem pracy było zbadanie, czy skrócenie czasu neutralizacji preparatu wynoszącego 5 minut po określonym czasie jego kontaktu z drobnoustrojami testowymi, zapewni zwalidowanie metody. Materiał i metody. Wybrano 14 preparatów zawierających substancje czynne należące do różnych grup chemicznych: alkohole, aldehydy, biguanidyny, czwartorzędowe związki amoniowe, fenole, pochodne amin, związki utleniające. Badania przeprowadzono wg norm fazy 1: EN 1040:2005 i EN 1275:2005, a następnie wg norm fazy 2 etapu 1: Draft EN 13727:2005 and EN 13624:2003. Do badań użyto zalecane standardowe szczepy bakterii i grzybów: S. aureus ATCC 6538, P. aeruginosa ATCC 15442, E. coli NCTC 10538, E. coli ATCC 10536, E. hirae ATCC 10541, C. albicans ATCC 10231 and A. brasiliensis ATCC 16404. Wyniki. Wyniki walidacji C dla wszystkich produktów i badanych szczepów mikroorganizmów spełniały wymagania norm, czyli były równe co najmniej połowie gęstości zawiesiny do walidacji (Nvo) zaledwie po 10 s neutralizacji. Ponadto, w równolegle przeprowadzonych testach aktywności przeciwdrobnoustrojowej uzyskano pozytywne wyniki, z wyjątkiem 5 produktów wobec A. brasiliensis. Wnioski. Wyniki badań potwierdzają, że czas kontaktu określany wg norm fazy 1 EN 1040:2005 i EN 1275:2005, jak również fazy 2 etapu 1: Draft EN 13727:2005 i EN 13624:2003, może być precyzyjnie określony mimo skrócenia czasu neutralizacji z 5 minut nawet do 10 sekund

Oral microbiome and peri-implant diseases: where are we now?

Rafal Pokrowiecki,1 Agnieszka Mielczarek,2 Tomasz Zareba,3 Stefan Tyski3,4 1Department of Head and Neck Surgery-Maxillofacial Surgery, Otolaryngology and Ophthalmology, Prof Stanislaw Popowski Voivoid Children Hospital, Olsztyn, 2Department of Conservative Dentistry, Medical University of Warsaw, 3Department of Antibiotics and Microbiology, National Medicines Institute, 4Department of Pharmaceutical Microbiology, Medical University of Warsaw, Warsaw, Poland Abstract: Peri-implant infective diseases (PIIDs) in oral implantology are commonly known as peri-implant mucositis (PIM) and periimplantitis (PI). While PIM is restricted to the peri-implant mucosa and is reversible, PI also affects implant-supporting bone and, therefore, is very difficult to eradicate. PIIDs in clinical outcome may resemble gingivitis and periodontitis, as they share similar risk factors. However, recent study in the field of proteomics and other molecular studies indicate that PIIDs exhibit significant differences when compared to periodontal diseases. This review aims to elucidate the current knowledge of PIIDs, their etiopathology and diversified microbiology as well as the role of molecular studies, which may be a key to personalized diagnostic and treatment protocols of peri-implant infections in the near future. Keywords: dental plaque, infection, titanium, microbiome, periimplantiti

In vitro studies of nanosilver-doped titanium implants for oral and maxillofacial surgery

Rafał Pokrowiecki,1,2 Tomasz Zaręba,3 Barbara Szaraniec,4 Krzysztof Pałka,5 Agnieszka Mielczarek,6 Elżbieta Menaszek,7 Stefan Tyski3,8 1Center for Cranio-Maxillo-Facial Surgery, Voivodeship Children’s Hospital, Olsztyn, 2Department of Oral Surgery, Jagiellonian Medical University, Kraków, 3Department of Antibiotics and Microbiology, National Medicines Institute, Warsaw, 4Faculty of Material Science and Ceramics, AGH University of Science and Technology, Kraków, 5Department of Materials Engineering, Lublin University of Technology, Lublin, 6Department of Conservative Dentistry, Medical University of Warsaw, Warsaw, 7Department of Cytobiology, Collegium Medicum, Jagiellonian University, Kraków, 8Department of Pharmaceutical Microbiology, Medical University of Warsaw, Warsaw, Poland Abstract: The addition of an antibacterial agent to dental implants may provide the opportunity to decrease the percentage of implant failures due to peri-implantitis. For this purpose, in this study, the potential efficacy of nanosilver-doped titanium biomaterials was determined. Titanium disks were incorporated with silver nanoparticles over different time periods by Tollens reaction, which is considered to be an eco-friendly, cheap, and easy-to-perform method. The surface roughness, wettability, and silver release profile of each disc were measured. In addition, the antibacterial activity was also evaluated by using disk diffusion tests for bacteria frequently isolated from the peri-implant biofilm: Streptococcus mutans, Streptococcus mitis, Streptococcus oralis, Streptococcus sanguis, Porphyromonas gingivalis, Staphylococcus aureus, and Escherichia coli. Cytotoxicity was evaluated in vitro in a natural human osteoblasts cell culture. The addition of nanosilver significantly increased the surface roughness and decreased the wettability in a dose-dependent manner. These surfaces were significantly toxic to all the tested bacteria following a 48-hour exposure, regardless of silver doping duration. A concentration of 0.05 ppm was sufficient to inhibit Gram-positive and Gram-negative species, with the latter being significantly more susceptible to silver ions. However, after the exposure of human osteoblasts to 0.1 ppm of silver ions, a significant decrease in cell viability was observed by using ToxiLight™ BioAssay Kit after 72 hours. Data from the present study indicated that the incorporation of nanosilver may influence the surface properties that are important in the implant healing process. The presence of nanosilver on the titanium provides an antibacterial activity related to the bacteria involved in peri-implantitis. Finally, the potential toxicological considerations of nanosilver should further be investigated, as both the antibacterial and cytotoxic properties may be observed at similar concentration ranges. Keywords: biomaterials, dental plaque, peri-implantitis, peri implant mucositis, silver, nanotechnology, nanomedicin

Antimicrobial activity of 10-(diphenylmethylene)-4-azatricyclo[5.2.1.0 2,6]dec-8-ene-3,5-dione derivatives

Antibacterial and antifungal activity of 10-(diphenylmethylene)-4- azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives were examined by the disk diffusion method (growth inhibition zone diameter in agar medium). The minimal inhibitory concentrations (MICs) for the most active agents were determined. Title compounds were also evaluated in vitro against HIV-1 virus and their cytotoxicity was determined. Aminoalkanol derivatives exhibited activity against the majority of microorganisms studied

Biological evaluation of 10-(diphenylmethylene)-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives

Antibacterial and antifungal activity of 10-(diphenylmethylene)-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives were examined by the disc-diffusion method (growth inhibition zone diameter in agar medium). The MIC's for the most active agents were determined. Title compounds were also evaluated in vitro against representatives of different virus classes. Most of the tested compounds exhibit activity against CVB-2 virus