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Gardnerella vaginalis outcompetes 29 other bacterial species isolated from BV patients in an in vitro biofilm formation model
Despite the worldwide prevalence of bacterial vaginosis (BV), its etiology is still unknown. Although BV has been associated with the presence of biofilm, the ability of BV-associated bacteria to form biofilms is still largely unknown. Here, we isolated 30 BV-associated species and characterized their virulence, using an in vitro biofilm formation model. Our data suggests that Gardnerella vaginalis had the highest virulence potential, as defined by higher initial adhesion and cytotoxicity of epithelial cells, as well as the greater propensity to form a biofilm. Interestingly, we also demonstrated that most of the BV-associated bacteria had a tendency to grow as biofilms. ; This work was supported by the European Union (FEDER/COMPETE funds) and the Fundacao para a Ciencia e a Tecnologia (reference FCOMP-01-0124-FEDER-008991 [PTDC/BIA-MIC/098228/2008] and RECI/EBB-EBI/0179/2012 ...
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Using an in-vitro biofilm model to assess the virulence potential of Bacterial Vaginosis or non-Bacterial Vaginosis Gardnerella vaginalis isolates
Gardnerella vaginalis is the most common species found in bacterial vaginosis (BV). However, it is also present in a significant proportion of healthy women and G. vaginalis vaginal colonization does not always lead to BV. In an effort to better understand the differences between G. vaginalis isolated from women with a positive (BV) versus a negative (non-BV) diagnosis of BV, we compared the virulence potential of 7 BV and 7 non-BV G. vaginalis isolates and assessed the virulence factors related to biofilm formation, namely: initial adhesion and cytotoxic effect, biofilm accumulation, susceptibility to antibiotics, and transcript levels of the known vaginolysin, and sialidase genes. Furthermore, we also determined the ability of G. vaginalis to displace lactobacilli previously adhered to HeLa cells. Our results showed that non-BV strains were less virulent than BV strains, as suggested by the lower cytotoxicity and initial adhesion to Hela cells. Significant differences in expression of known virulence genes were also detected, further suggesting a higher virulence potential of the BV associated G. vaginalis. Importantly, we demonstrated that BV associated G. vaginalis were able to displace pre-coated vaginal protective lactobacilli and we hypothesize this to be a trigger for BV development. ; European Union funds (FEDER/COMPETE) and by national funds (FCT) under the project with reference FCOMP-01-0124-FEDER-008991 (PTDC/BIA-MIC/098228/2008). FCT Strategic Project of UID/BIO/04469/2013 unit the project NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte(ON.2 – O Novo Norte), QREN, FEDER, and the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). FCT individual fellowship ...
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Surface modification of an intraocular lens material by plasma-assisted grafting with 2- hydroxyethyl methacrylate (HEMA), for controlled release of moxifloxacin
Endophthalmitis, an inflammation of the eye due to perioperative infection, may occur after cataract surgery. Intraocular lenses (IOLs) loaded with an antibiotic have been proposed as an alternative to the conventional postoperative endophthalmitis prophylaxis, since the antibiotic is delivered directly to the target site. In this work, an IOL-based antibiotic releasing system was prepared from a copolymer used in the production of IOLs and a fluoroquinolone used in endophthalmitis prophylaxis (moxifloxacin, MFX). Argon plasma-assisted grafting with 2- hydroxyethyl methacrylate (HEMA) in the presence of MFX was the approach selected for surface modification, with MFX loaded both by entrapment in the grafted polyHEMA coating and by soaking. Surface and bulk properties were evaluated before and after surface modification and the MFX release profiles were obtained both in batch mode (sink conditions) and under hydrodynamic conditions, employing a purpose-built microfluidic cell, which simulated the hydrodynamic conditions around the eye lens. The effect of storage on the release profile of the best system was also assessed. The best system released MFX for ca. 15 days above the minimum inhibitory concentration for Staphylococcus aureus and Staphylococcus epidermidis. The released MFX showed antimicrobial activity against these bacteria and was non-cytotoxic against corneal endothelial cells. ; Work developed under the M-era.Net research project titled SurfLenses − Surface modifications to control drug release from therapeutic ophthalmic lenses, funded by Fundação para a Ciência e a Tecnologia (FCT; grants M-ERA.NET/0005/2012, M-ERA.NET/0006/2012 and PTDC/CTMBIO/ 3640/2014), and co-funded by the European Union through the QREN, POFC-COMPETE and FEDER programmes. Additional funding from grant PEstOE/QUI/UI0100/2013 (FCT) is also acknowledged. I. J. Correia and T. R. Correia acknowledge support by FEDER funds through the POCI - COMPETE 2020 - Operational Programme Competitiveness and Internationalisation in Axis I - Strengthening research, technological development and innovation (grant POCI-01-0145-FEDER-007491) and National Funds by FCT (grant UID/Multi/00709/2013). A. Pimenta, P. Alves and P. Coimbra thank FCT for personal grants SFRH/BD/52334/2013, SFRH/BPD/69410/2010 and SFRH/BPD/73367/2010, respectively.
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