Identification of candida clinical isolates by PCR fingerprinting : a contribution to the study of molecular epidemiology of candidiasis in portugal

PCR fingerprinting with a single non-specific primer (T3B) was used to type yeast clinical isolates obtained from two Medical Institutions in north Portugal. Of the 177 strains isolated, 112 were obtained from vaginal swabs, 24 from urine, 23 from the upper respiratory system, seven from the anal mucosa and 11 were isolated from various sources including blood, pus, catheter and peritoneal fluid. All the isolates belonged to the genus Candida being the profiles obtained highly similar within a species and clearly distinct among species. Seven different species were identified: C. albicans, C. tropicalis, C. glabrata, C. guilliermondii, C. parapsilosis, C. krusei and C.lusitaniae. This methodology also allowed the distinction of C. dubliniensis which is very closely related to C. albicans. Cluster analysis of the global fingerprints obtained originated, in general, groups corresponding to each species analysed except for five strains which were submitted to 26S and ITS rDNA sequencing to confirm their identity. We demonstrate that although C. albicans is the predominant species found, other Candida species were present accounting for over 20% of the strains isolated. The most common non albicans species were C. tropicalis, C. glabrata and C. parapsilosis. Due to its predominance over the other species C. albicans was present in all types of clinical material except in blood samples. C. tropicalis was mainly recovered from the urine and respiratory tract. This study represents the first large-scale approach to the knowledge of Candida species present in hospital settings in Portugal.Fundação para a Ciência e Tecnologia (FCT) Ciências do Ambiente da Universidade do Minho (CCA

Gum-based nanocomposites for the removal of metals and dyes from waste water

Funding Information: Open access funding provided by FCT|FCCN (b-on). M.B.T acknowledges support from HEC (Higher Education Commission) of Pakistan. S.A.C.C. acknowledges support from FCT/MCTES (Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through projects UIDB/50006/2020 and UIDP/50006/2020 and for the Scientific Employment Stimulus—Institutional Call (CEECINST/00102/2018). Publisher Copyright: © 2023, The Author(s).The importance of water for all living organisms is unquestionable and protecting its sources is crucial. In order to reduce water contaminants, like toxic metals and organic dyes, researchers are exploring different techniques, such as adsorption, photocatalytic degradation, and electrolysis. Novel materials are also being sought. In particular, biopolymers like guar gum and xanthan gum, that are eco-friendly, non-toxic, reusable, abundant and cost-effective, have enormous potential. Gum-based nanocomposites can be prepared and used for removing heavy metals and colored dyes by adsorption and degradation, respectively. This review explains the significance of gum-based nanomaterials in waste water treatment, including preparative steps, characterization techniques, kinetics models, and the degradation and adsorption mechanisms involved.publishersversionpublishe

Biocompatibility of a self-assembled crosslinkable hyaluronic acid nanogel

Hyaluronic acid nanogel (HyA-AT) is a redox sensitive crosslinkable nanogel, obtained through the conjugation of a thiolated hydrophobic molecule to the hyaluronic acid chain. Engineered nanogel was studied for its biocompatibility, including immunocompatibility and hemocompatability. The nanogel did not compromise the metabolic activity or cellular membrane integrity of 3T3, microvascular endothelial cells, and RAW 264.7 cell lines, as determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase release assays. Also, we didn't observe any apoptotic effect on these cell lines through the Annexin V-FITC test. Furthermore, the nanogel cell internalization was analyzed using murine bone marrow derived macrophages, and the in vivo and ex vivo biodistribution of the Cy5.5 labeled nanogel was monitored using a non-invasive near-infrared fluorescence imaging system. The HyA-AT nanogel exhibits fairly a long half-live in the blood stream, thus showing potential for drug delivery applications.The authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/ BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the Project “BioHealth – Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124- FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. The authors would like to acknowledge also the support of FCT for the PhD grant reference SFRH/BD/61516/2009. They would also like to thank Bioimaging department on Molecular Medicine Institute (IMM) in Lisbon, namely Dr José Rino and Dr António Temudo. Also thank the animal facilities in IMM (Lisbon), specially Dr. Dolores Bonaparte and Dr. Joana Marques. Finally, the authors thank Dr Africa Gonzalez and Mercedes Pelletero the performance of the studies on the activation of complement

When gold stops glittering: corrosion mechanisms of René Lalique's Art Nouveau jewellery

ABSTRACT: Art Nouveau jewellery created by René Lalique is presently corroded. To identify the corrosion processes, Au-Ag-Cu alloys with compositions comparable to those used in the René Lalique’s jewellery were fabricated to be exposed to sulphide-containing environments. Using SEM-EDS, XRD, UV-Vis spectroscopy and ellipsometry, it was for the first time demon-strated that at the surface of tarnished Au alloys forms a corrosion film with a layer-by-layer structure. Considering the complex refractive indices of bulk Cu and Ag oxides and sulphides, a two-step corrosion mechanism was proposed. The formation of Cu-based compounds during the early corrosion stages is followed by the formation of Ag-based compounds. The thinness of the formed film, shown for one of the gold alloys to be of 80 nm, is due to a corrosion kinetics controlled by the presence of Au and by the formation of an Au-S self-assembled monolayer. The corrosion mechanism of gold alloys raises a new conservation challenge concerning the removal of nanometric layers.info:eu-repo/semantics/publishedVersio

Glutaraldehyde exposed Pseudomonas fluorescens: a case of biofilm persistence?

From the assessment of the recovery capability of pseudomonas fluorescens atcc 13525t after exposure to several glutaraldehyde (gta) concentrations (100, 200 and 400 mg/l) and exposure times (1 and 2 hours), it was found that, for gta concentrations above 100 mg/l, whatever the exposure time, bacterial cells presented different growth patterns in solid media. after this statement, the recovered cells were initially characterized using api ne20 strips and species identification was obtained using the api database. the type culture and the cells obtained after treatment with concentrations below 200 mg/l were identified as p. fluorescens. conversely, the identification of cells exposed to higher concentrations of gta failed. the electrophoretic profiles of both the type culture and the cells exposed to gta were obtained by pcr, using the primer t3b. the results showed identical profiles for the type culture and the cells exposed to low gta concentrations, and a totally different pattern for cells exposed to gta concentrations above 200 mg/l. sequencing of the 16s rdna gene is under way in order to further clarify the differences observed. the p. fluorescens atcc 13525 (used as control) and the cells treated with 200 mg/l of gta during 2 hours were selected for further studies. a comparative study was carried out between the above referred cells in terms of morphological structure, surface properties, respiratory activity, biofilm formation ability and susceptibility to gta. the results showed that the cells treated with 200 mg/l of gta presented an elongated structure, were about 30 times less active in terms of respiratory activity and were more hydrophilic. concerning biofilm formation, both tested cells presented biofilm formation ability, but the gta treated cells produced about 2 times more mass of biofilm. however, this biofilm had a specific respiratory activity 3 times less than the one formed by the control culture. the biofilm behaviour immediately after exposure to 200 mg/l of gta during 2 hours, was similar for both situations studied, since a low biofilm removal and inactivation was achieved. however, 7 hours after gta exposure, only 55% of the biofilm formed by the control culture remained attached to the surface, while for the biofilms formed by the treated cells all the deposit remained attached to the surface. the results obtained in this work indicate that cells submitted to gta treatment may give rise to biofilms harder to remove and consequently more persistent, than non-treated cells. therefore, care must be taken in the selection and application of biocides in industrial biofilms

ERP mismatch response to phonological and temporal regularities in speech

Predictions of our sensory environment facilitate perception across domains. During speech perception, formal and temporal predictions may be made for phonotactic probability and syllable stress patterns, respectively, contributing to the efficient processing of speech input. The current experiment employed a passive EEG oddball paradigm to probe the neurophysiological processes underlying temporal and formal predictions simultaneously. The component of interest, the mismatch negativity (MMN), is considered a marker for experience-dependent change detection, where its timing and amplitude are indicative of the perceptual system's sensitivity to presented stimuli. We hypothesized that more predictable stimuli (i.e. high phonotactic probability and first syllable stress) would facilitate change detection, indexed by shorter peak latencies or greater peak amplitudes of the MMN. This hypothesis was confirmed for phonotactic probability: high phonotactic probability deviants elicited an earlier MMN than low phonotactic probability deviants. We do not observe a significant modulation of the MMN to variations in syllable stress. Our findings confirm that speech perception is shaped by formal and temporal predictability. This paradigm may be useful to investigate the contribution of implicit processing of statistical regularities during (a)typical language development.Maastricht University (Grant to BMJ to support women in higher academic positions) and Netherlands Organization for Scientific Research (NWO) 452-16-004info:eu-repo/semantics/publishedVersio

siRNA inhibition of endocytic pathways to characterize the cellular uptake mechanisms of folate-functionalized glycol chitosan nanogels

Glycol chitosan nanogels have been widely used in gene, drug, and contrast agent delivery in an effort to improve disease diagnosis and treatment. Herein, we evaluate the internalization mechanisms and intracellular fate of previously described glycol chitosan nanogels decorated with folate to target the folate receptor. Uptake of the folate-decorated nanogel was impaired by free folate, suggesting competitive inhibition and shared internalization mechanisms via the folate receptor. Nanogel uptake was shown to occur mainly through flotillin-1 and Cdc42-dependent endocytosis. This was determined by inhibition of uptake reduction observed upon siRNA depletion of these two proteins and the pathways that they regulate. The data also suggest the involvement of the actin cytoskeleton in nanogel uptake via macropinocytosis. After 7 h of incubation with HeLa cells, approximately half of the nanogel population was localized in endolysosomal compartments, whereas the remaining 50% of the material was in undefined regions of the cytoplasm. Glycol chitosan nanogels may thus have potential as drug delivery vectors for targeting different intracellular compartments.BioHealth - Biotechnology and Bioengineering approaches to improve health quality, Ref. NORTE-07-0124-FEDER-000027, cofunded by the Programa Operacional Regional do Norte (ON.2 − O Novo Norte), QREN, FEDER. P.P. was funded through an FCT Ph.D. grant (SFRH/BD/64977/2009). Funding is also acknowledged from a Cancer Research UK studentship (C36040/A11652), EPSRC Grant (EP/J021334/1 to A.T.J. and E.S.

Potential of mannan or dextrin nanogels as vaccine carrier/adjuvant systems

Polymeric nanogels have been sophisticatedly designed promising a new generation of vaccine delivery/adjuvant systems capable of boosting immune response, a strategic priority in vaccine design. Here, nanogels made of mannan or dextrin were evaluated for their potential as carriers/adjuvants in vaccine formulations. Since lymph nodes are preferential target organs for vaccine delivery systems, nanogels were biotin-labeled, injected in the footpad of rats, and their presence in draining lymph nodes was assessed by immunofluorescence. Nanogels were detected in the popliteal and inguinal lymph nodes by 24h upon subcutaneous administration, indicating entrapment in lymphatic organs. Moreover, the model antigen ovalbumin was physically encapsulated within nanogels and physicochemically characterized concerning size, zeta potential, ovalbumin loading, and entrapment efficiency. The immunogenicity of these formulations was assessed in mice intradermally immunized with ovalbuminmannan or ovalbumindextrin by determining ovalbumin-specific antibody serum titers. Intradermal vaccination using ovalbuminmannan elicited a humoral immune response in which ovalbumin-specific IgG1 levels were significantly higher than those obtained with ovalbumin alone, indicating a TH2-type response. In contrast, dextrin nanogel did not show adjuvant potential. Altogether, these results indicate that mannan nanogel is a material that should be explored as a future antigen delivery system.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work is supported by the Fundação para a Ciência e a Tecnologia (FCT) Portugal, post-doc grant SFRH/BPD/70524/2010 and the International Iberian Nanotechnology Laboratory (INL), PhD grant. The authors thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). The authors also acknowledge the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462)

Probable Person-to-Person Transmission of Legionnaires’ Disease

Correspondence to the Editor.Legionnaires’ disease is an often severe form of pneumonia that is typically acquired by susceptible persons (e.g., elderly persons and smokers) through inhalation of aerosols that contain legionella species.1-4 A cluster of cases of this disease occurred in Vila Franca de Xira, Portugal, in 2014

Zymomonas mobilis an emerging microbial cell factory to produce prebiotics

info:eu-repo/semantics/publishedVersio