Publications by authors named "Rita Teixeira-Santos"

The ability of bacteria to adhere to and form biofilms on food contact surfaces poses serious challenges, as these may lead to the cross-contamination of food products. Biomimetic topographic surface modifications have been explored to enhance the antifouling performance of materials. In this study, the topography of two plant leaves, var.

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The application of graphene-based materials in medicine has led to significant technological breakthroughs. The remarkable properties of these carbon materials and their potential for functionalization with various molecules and compounds make them highly attractive for numerous medical applications. To enhance their functionality and applicability, extensive research has been conducted on surface modification of graphene (GN) and its derivatives, including modifications with antimicrobials, metals, polymers, and natural compounds.

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Chemically modified carbon nanotubes are recognized as effective materials for tackling bacterial infections. In this study, pristine multi-walled carbon nanotubes (p-MWCNTs) were functionalized with nitric acid (f-MWCNTs), followed by thermal treatment at 600 °C, and incorporated into a poly(dimethylsiloxane) (PDMS) matrix. The materials' textural properties were evaluated, and the roughness and morphology of MWCNT/PDMS composites were assessed using optical profilometry and scanning electron microscopy, respectively.

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Graphene has been broadly studied, particularly for the fabrication of biomedical devices, owing to its physicochemical and antimicrobial properties. In this study, the antibiofilm efficacy of graphene nanoplatelet (GNP)-based composites as coatings for urinary catheters (UCs) was investigated. GNPs were functionalized with nitrogen (N-GNP) and incorporated into a polydimethylsiloxane (PDMS) matrix.

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Currently, multidrug-resistant (MDR) infections are one of the most important threats, driving the search for new antimicrobial compounds. Cationic peptide antibiotics (CPAs) and ceragenins (CSAs) contain in their structures cationic groups and adopt a facially amphiphilic conformation, conferring the ability to permeate the membranes of bacteria and fungi. Keeping these features in mind, an amine steroid, DOCA-NH2, was found to be active against reference strains and MDR isolates of Gram-positive and and Gram-negative and .

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Microorganisms tend to adhere to food contact surfaces and form biofilms, which serve as reservoirs for bacteria that can contaminate food. As part of a biofilm, bacteria are protected from the stressful conditions found during food processing and become tolerant to antimicrobials, including traditional chemical sanitisers and disinfectants. Several studies in the food industry have shown that probiotics can prevent attachment and the consequent biofilm formation by spoilage and pathogenic microorganisms.

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Article Synopsis
  • - Biofouling presents significant economic and ecological issues in the marine industry, leading to a growing interest in non-toxic antifouling coatings, particularly those using carbon nanomaterials like graphene nanoplatelets (GNP).
  • - A study was conducted to analyze how GNP impacts biofilm development from marine bacteria, using a GNP/polydimethylsiloxane (PDMS) surface and evaluating its effectiveness over 42 days in marine-simulating conditions.
  • - Results showed that the GNP-containing surface significantly reduced biofilm cell count and thickness while causing membrane damage and increased reactive oxygen species production in bacteria, indicating its potential as an effective marine antifouling coating.
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  • * Chitosan (CS), a natural polymer known for its non-toxicity and antimicrobial properties, is used to create poly(lactic acid) (PLA)-CS surfaces for marine paints, utilizing waste from the fishery industry as a source of CS.
  • * The study shows that PLA-CS surfaces effectively reduce bacterial cell counts by up to 68% and biofilm thickness by 36%, with the effectiveness varying based on the molecular weight of CS, supporting its potential use in reducing marine biofouling and
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Although carbon materials are widely used in surface engineering, particularly graphene (GP) and carbon nanotubes (CNTs), the application of these nanocomposites for the development of antibiofilm marine surfaces is still poorly documented. The aim of this study was, thus, to gather and discuss the relevant literature concerning the antifouling performance of carbon-based coatings against marine micro- and macrofoulers. For this purpose, a PRISMA-oriented systematic review was conducted based on predefined criteria, which resulted in the selection of thirty studies for a qualitative synthesis.

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  • The rise in implant-associated infections (IAIs) continues despite improvements in materials and surgical methods, primarily due to microbes adhering and forming biofilms on implants.
  • This study critically evaluates the effectiveness of chitosan-based coatings in preventing IAIs, using a systematic review methodology to analyze forty relevant studies.
  • The results show that combining chitosan with enzymes, antimicrobial peptides, and polymers enhances its antimicrobial properties and creates better coatings that are biocompatible and durable for medical implants.
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Novel technologies to prevent biofilm formation on urinary tract devices (UTDs) are continually being developed, with the ultimate purpose of reducing the incidence of urinary infections. Probiotics have been described as having the ability to displace adhering uropathogens and inhibit microbial adhesion to UTD materials. This work aimed to evaluate the effect of pre-established biofilms on the adhesion of to medical-grade silicone.

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  • Implantable medical devices (IMDs) can develop microbial biofilms, leading to infections, and the study investigates using chitosan (CS) to combat this issue.
  • Chitosan coatings on polylactic acid (PLA) films were tested for their ability to inhibit bacterial biofilms, with different molecular weights (Mw) affecting their antimicrobial effectiveness.
  • Results showed that low Mw CS significantly reduced biofilm formation by up to 96%, suggesting it could be an effective coating for IMDs to prevent bacterial colonization.
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Since biofilm formation by microfoulers significantly contributes to the fouling process, it is important to evaluate the performance of marine surfaces to prevent biofilm formation, as well as understand their interactions with microfoulers and how these affect biofilm development and structure. In this study, the long-term performance of five surface materials-glass, perspex, polystyrene, epoxy-coated glass, and a silicone hydrogel coating-in inhibiting biofilm formation by cyanobacteria was evaluated. For this purpose, cyanobacterial biofilms were developed under controlled hydrodynamic conditions typically found in marine environments, and the biofilm cell number, wet weight, chlorophyll content, and biofilm thickness and structure were assessed after 49 days.

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Although laboratory assays provide valuable information about the antifouling effectiveness of marine surfaces and the dynamics of biofilm formation, they may be laborious and time-consuming. This study aimed to determine the potential of short-time adhesion assays to estimate how biofilm development may proceed. The initial adhesion and cyanobacterial biofilm formation were evaluated using glass and polymer epoxy resin surfaces under different hydrodynamic conditions and were compared using linear regression models.

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Although high-performance carbon materials are widely used in surface engineering, with emphasis on carbon nanotubes (CNTs), the application of CNT nanocomposites on medical surfaces is poorly documented. In this study, we aimed to evaluate the antimicrobial and anti-adhesive properties of CNT-based surfaces. For this purpose, a PRISMA-oriented systematic review was conducted based on predefined criteria and 59 studies were selected for the qualitative analysis.

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Medical device-associated infections (MDAI) are a critical problem due to the increasing usage of medical devices in the aging population. The inhibition of biofilm formation through the use of probiotics has received attention from the medical field in the last years. However, this sparse knowledge has not been properly reviewed, so that successful strategies for biofilm management can be developed.

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Understanding the conditions affecting cyanobacterial biofilm development is crucial to develop new antibiofouling strategies and decrease the economic and environmental impact of biofilms in marine settings. In this study, we investigated the relative importance of shear forces and surface hydrophobicity on biofilm development by two coccoid cyanobacteria with different biofilm formation capacities. The strong biofilm-forming was used along with the weaker biofilm-forming sp.

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Numerous studies have explored the antibacterial properties of different types of honey from all around the world. However, the data available describing how honey acts against bacteria are few. The aim of this study was to apply a flow cytometry (FC) protocol to examine and characterize the primary effects of three varieties of honey (avocado, chestnut and polyfloral) upon physiological status of and cells to reveal their antibacterial action mechanisms.

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Several studies have explored the antimicrobial properties of manuka honey (MkH). However, the data available regarding antibacterial action mechanisms are scarcer. The aim of this study was to scrutinize and characterize primary effects of manuka honey (MkH) upon the physiological status of and (as Gram-positive and Gram-negative bacteria models, respectively), using flow cytometry (FC) to reveal its antibacterial action mechanisms.

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  • The study focused on understanding the distribution of Malassezia species in patients with skin conditions and their susceptibility to antifungal treatments.
  • It was conducted over three years at a University Hospital, identifying isolated Malassezia through sequencing and evaluating their response to various antifungals.
  • Findings revealed that M. sympodialis was the most common species, with previous use of topical corticosteroids increasing resistance to certain antifungals, suggesting terbinafine could be a potential treatment option for resistant cases.
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One of teachers' concerns, with students in general and medical students in particular, is to ensure as much as possible that information goes from students' short-term memories to their long-term memories. The present study focuses on knowledge retention in Medical Microbiology and assesses the effectiveness of some strategies implemented for short- and long-term retention. A pre- and post-test was used to assess student's learning.

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Article Synopsis
  • - The study assessed the effectiveness of the FASTinov kit for antimicrobial susceptibility testing (AST) of Gram-negative bacteria directly from blood cultures at a Portuguese University Hospital, involving 102 positive samples.
  • - Results showed that the FASTinov kit provided results in just 2 hours, compared to 51 hours for the Vitek2 method, and had a 98% agreement with the gold standard microdilution technique.
  • - The research highlighted that 16.7% of patients initially received inappropriate antibiotic therapy, leading to a significantly longer hospital stay, emphasizing the importance of rapid AST for effective infection management.
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Patients with multiple comorbidities are often administered simultaneously or sequentially antifungals and antibacterial agents, without full knowledge of the consequences of drug interactions. Considering the clinical relevance of liposomal amphotericin B (L-AMB), the association between L-AMB and six antibacterial agents was evaluated against four clinical isolates and one type strain of Candida spp. and two clinical isolates and one type strain of Aspergillus fumigatus.

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The synergy of carbapenem combinations regarding Enterobacteriaceae producing different types of carbapenemases was study through different approaches: flow cytometry and computational analysis. Ten well characterized Enterobacteriaceae (KPC, verona integron-encoded metallo-β-lactamases -VIM and OXA-48-like enzymes) were selected for the study. The cells were incubated with a combination of ertapenem with imipenem, meropenem, or doripenem and killing kinetic curves performed with and without reinforcements of the drugs.

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In vitro resistance to amphotericin B is an extremely rare event among pathogenic yeasts. However, in vivo response is sometimes reduced, resulting in an unfavorable outcome. Such adverse outcomes might be related to subfungicidal plasma concentrations.

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