Long-term dissemination of acquired AmpC β-lactamases among Klebsiella spp. and Escherichia coli in Portuguese clinical settings

We investigated the occurrence, diversity and molecular epidemiology of genes coding for acquired AmpC β-lactamases (qAmpC) among clinical isolates of Enterobacteriaceae lacking inducible chromosomal AmpCs in Portugal. A total of 675 isolates non-susceptible to broad-spectrum cephalosporins obtained from four hospitals and three community laboratories during a 7-year period (2002-2008) were analysed. The presence of genes coding for qAmpC was investigated by phenotypic criteria, polymerase chain reaction (PCR) and sequencing. Bacterial identification, antibiotic susceptibility testing, conjugation assays and clonal analysis were performed by standard procedures. The presence of bla qAmpC genes was detected in 50 % (50/100; 41 Klebsiella pneumoniae, 5 Escherichia coli, 4 Klebsiella oxytoca) of the presumptive qAmpC producers. DHA-1, detected in those species, was the most prevalent qAmpC (94 %, 47/50), being identified since 2003 and throughout the studied period in different institutions. Despite the high clonal diversity observed, three DHA-1-producing Klebsiella spp. clones were more frequently identified. CMY-2 (6 %, 3/50) was observed in B1-E. coli clones. Conjugative transfer was only observed in one (2 %) CMY-2-producing isolate. Most qAmpC producers (94 %, 47/50) co-expressed SHV-type and/or OXA-1 or CTX-M-32 extended-spectrum β-lactamases (ESBLs). To the authors' knowledge, this is the first description of the molecular epidemiology and the long-term dissemination of qAmpC-producing Enterobacteriaceae in Portuguese clinical settings, highlighting an evolution towards a more complex epidemiological situation regarding cephalosporin resistance in Portugal

Estudo da transferência de massa em reactores agitados para a produção de biopolímeros

Tese de mestrado integrado. Engenharia Química. Universidade do Porto. Faculdade de Engenharia. 201

Silver Nanostar-Based SERS for the Discrimination of Clinically Relevant Acinetobacter baumannii and Klebsiella pneumoniae Species and Clones

And project HEALTH-UNORTE I&D&I NORTE-01-0145-FEDER-000039 cofinanced by European Regional Development Fund (ERDF), through the NORTE 2020 (Programa Operacional Regional do Norte 2014/2020). AN was supported by Portuguese funds through FCT in the context of the CEEC program (2021.02252.CEECIND/CP1662/CT0009). FG was supported by Portuguese funds through FCT in the context of the transitional norm (DL57/2016/CP1346/CT0034). NL acknowledges support from a grant of the Romanian Ministry of Research and Innovation, CCCDI-UEFISCDI, project number PN-III-P4-ID-PCE-2020-1292, within PNCDI III. Publisher Copyright: © 2023 by the authors.The development of rapid, reliable, and low-cost methods that enable discrimination among clinically relevant bacteria is crucial, with emphasis on those listed as WHO Global Priority 1 Critical Pathogens, such as carbapenem-resistant Acinetobacter baumannii and carbapenem-resistant or ESBL-producing Klebsiella pneumoniae. To address this problem, we developed and validated a protocol of surface-enhanced Raman spectroscopy (SERS) with silver nanostars for the discrimination of A. baumannii and K. pneumoniae species, and their globally disseminated and clinically relevant antibiotic resistant clones. Isolates were characterized by mixing bacterial colonies with silver nanostars, followed by deposition on filter paper for SERS spectrum acquisition. Spectral data were processed with unsupervised and supervised multivariate data analysis methods, including principal component analysis (PCA) and partial least-squares discriminant analysis (PLSDA), respectively. Our proposed SERS procedure using silver nanostars adsorbed to the bacteria, followed by multivariate data analysis, enabled differentiation between and within species. This pilot study demonstrates the potential of SERS for the rapid discrimination of clinically relevant A. baumannii and K. pneumoniae species and clones, displaying several advantages such as the ease of silver nanostars synthesis and the possible use of a handheld spectrometer, which makes this approach ideal for point-of-care applications.publishersversionpublishe

Production and optimization of 316L stainless steel dimples by laser surface texturing using Nd: YAG laser

Surface patterning is of increasing interest in modern manufacturing processes to achieve better results in terms of wear resistance and friction of mechanical parts and tools and, consequently, to improve their lifetime in service conditions [1]. Several approaches have been used to modify the surface properties of steel components, namely deposition of coatings, sandblasting, and texturing by electron beam, electric arc, or laser ablation [1,2]. In this work, laser technology was explored to produce dimples on the surface of 316L stainless steel samples. The production of textures can have several purposes, namely in tribological applications where they can reduce wear by acting as a reservoir for the lubricant or be reinforced with other materials (e.g. ceramics or intermetallic compounds), capable of improving the surface properties [1–3]. This work presents a detailed study on the texturing of a 316L stainless steel (dimples - circle design) by an Nd: YAG laser and its surface characterization by Scanning Electron Microscopy and analysis software (Image J) for obtaining their width (diameter) and depth. The texturing parameters are discussed herein. Results show that the width of the dimples is little influenced by the scan speed and wobble, but strongly affected by the combination of laser power and number of passes. On the other hand, wobble strongly influenced the depth of the dimples.This work was supported by FCT (Fundação para a Ciência e a Tecnologia) national funds, under the national support to R&D units grant, through the grant SFRH/BD/147460/2019, the project UIDB/04436/2020 and UIDP/04436/2020 and, also by project UIDB/00285/2020

3D Multi-Material Laser Powder Bed Fusion of 420 stainless steel-Cu parts for Plastic Injection Mold Inserts

Plastic injection molding is one of the fastest-growing industries in the world. However, although it presents numerous advantages, the costs associated with the mold and machine are high and, therefore, this process is only profitable for mass production. Moreover, the reduction in the cycle time, more specifically the cooling time, has been a never-ending challenge since it has a direct influence on production costs. This study is focused on the production of 420 stainless steel-copper solutions by 3D multi-material laser powder bed fusion. This novel material’s design concept allows combining the high mechanical resistance of the steel alloy and the high thermal conductivity of the copper. The processing parameters and strategies as well as the transition zone between these materials are of the most challenging and important aspects both from a mechanical and metallurgical point of view. The obtained results show that this approach is effective to produce inserts of copper in a 420 stainless steel capable of improving the in-service conditions of a plastic injection mold, enhancing its performance and life

Bioactive and nutritional potential of medicinal and aromatic plant (MAP) seasoning mixtures

Medicinal and aromatic plants (MAPs), worldwide appreciated and used as condiments, dyes, and preservatives, possess several biological properties that justify their continuous application in the food industry. In the present study, the nutritional and chemical profiles, as well as the bioactive properties of four combinations of condiments, sold for seasoning poultry, meat, fish, and salads, were evaluated. Twenty-five phenolic compounds (HPLC-DAD-ESI/MS) were identified, with apigenin-O-malonyl-pentoside-hexoside as the major compound detected in all extracts. Oxalic and citric acids were identified in all mixtures (UFLC-PDA), as well as all the four tocopherol isoforms (HPLC-fluorescence). Regarding bioactivities, the mixtures for meat and salads (TBARS) and meat and poultry (OxHLIA) stood out for their antioxidant potential, whereas for the anti-inflammatory and antitumor properties, the mixtures revealing the greatest results were those for poultry and salad, respectively. In terms of antimicrobial activity, all the mixtures revealed the capacity to inhibit the growth of some bacterial strains. In brief, condiment mixtures showed to be a good source of bioactive compounds, as they confer health benefits, validating the importance of their inclusion in the human diet as a good dietary practice.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); national funding by F.C.T. and P.I., through the institutional scientific employment program-contract for C.P., M.I.D., R.C.C. and L.B. contracts and A.K.M. (2020.06231.BD) and M.A.-O. (2020.06297.BD) PhD grants. To FEDER-Interreg España-Portugal programme for financial support through the project TRANSCoLAB 0612_TRANS_CO_LAB_2_P; to ERDF through the Regional Operational Program North 2020, within the scope of Project GreenHealth-Norte-01-0145-FEDER-000042.info:eu-repo/semantics/publishedVersio

Dissemination of Clonally Related Escherichia coli Strains Expressing Extended-Spectrum β-Lactamase CTX-M-15

E. coli ST131 and ST405 and multidrug-resistant IncFII plasmids may determine spread of this lactamase

Optimization of zirconia surface textured designs using Nd:Yag laser for biomedical applications

The development of surface textured designs has influence in primary stability of surgically placed implants since a textured surface allows to firmer mechanical link to the surrounding tissue. Laser technology has been investigated to develop new surface designs on green zirconia compacts by cold pressing. Nd:Yag laser were used to produce several strategies and different laser parameters (laser power, speed and laser passages) were tested to evaluate their impact on cavities geometry and depth. The surface texture designs were analysed by Scanning Electron Microscopy (SEM) and regular geometries such as cavities or pillars were observed. The distance between lines have a strong impact on texturing quality and should be combined with optimum power and speed conditions. Regarding the optimized conditions, several surface textured patterns were created in both green and sintered zirconia compacts. This study allowed to conclude that only some texturing strategies are suitable to obtain high quality surface textured patterns. Otherwise, the remaining strategies are potential solutions for obtaining high quality machined structures (laser does not machine cavities but crosses the entire bulk). High strength zirconia scaffolds were machined by laser and CNC machining technologies and the two promising technologies were compared.This work is supported by FCT (Fundação para a Ciência e a Tecnologia) through the grant SFRH/BD/148031/2019, the project UIDB/04436/2020 and UIDP/04436/2020

Children day care center: exposition or protection environment to intestinal parasites infestation in Aracaju, SE

Para avaliar se creches são ambientes protetores ou propiciadores de infestação intestinal, foi feito exame coproparasitológico de crianças de creche e grupo controle. Creche relacionou-se à maior prevalência de parasitoses (63% x 41,4 % ; p<0,01), com risco de infestação 1,5 vez maior