Filipe Mergulhão

Filipe Mergulhão
University of Porto | UP · Faculty of Engineering

PhD - Biotechnology

About

141
Publications
42,944
Reads
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3,022
Citations
Additional affiliations
September 2005 - present
University of Porto
Position
  • Research Assistant

Publications

Publications (141)
Article
The adhesion of Escherichia coli to glass and polydimethylsiloxane (PDMS) at different flow rates (between 1 and 10 ml.s−1) was monitored in a parallel plate flow chamber in order to understand the effect of surface properties and hydrodynamic conditions on adhesion. Computational fluid dynamics was used to assess the applicability of this flow cha...
Article
The aim of this work was to test materials typically used in the construction of medical devices regarding their influence in the initial adhesion, biofilm development and antibiotic susceptibility of Escherichia coli biofilms. Adhesion and biofilm development was monitored in 12-well microtiter plates containing coupons of different biomedical mat...
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Semi-circular flow cells are often used to simulate the formation of biofilms in industrial pipes with circular section because their planar surface allows easy sampling using coupons. Computational fluid dynamics was used to assess whether the flow in pipe systems can be emulated by the semi-circular flow cells that are used to study biofilm forma...
Article
The secretory production of recombinant proteins by the Gram-negative bacterium Escherichia coli has several advantages over intracellular production as inclusion bodies. In most cases, targeting protein to the periplasmic space or to the culture medium facilitates downstream processing, folding, and in vivo stability, enabling the production of so...
Article
Bioprocesses based on surface-associated microorganisms are emerging in environmental and industrial areas due to the physiological specificities and heterogeneities of biofilm cells. This study describes a simple and accurate method for evaluating the recombinant protein expression at a single-cell scale during Escherichia coli biofilm development...
Article
The development of harmless substances to replace biocide-based coatings used to prevent or manage marine biofouling and its unwanted consequences is urgent. The formation of biofilms on submerged marine surfaces is one of the first steps in the marine biofouling process, which facilitates the further settlement of macrofoulers. Anti-biofilm proper...
Article
In recent years, abundant research has been performed on biofilms for the production of compounds with biotechnological and industrial relevance. The use of biofilm platforms has been seen as a compelling approach to producing fine and bulk chemicals such as organic acids, alcohols, and solvents. However, the production of recombinant proteins usin...
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Hydrodynamics play an important role in the rate of cell attachment and nutrient and oxygen transfer, which can affect biofilm development and the level of recombinant protein production. In the present study, the effects of different flow conditions on the development of Escherichia coli biofilms and the expression of a model recombinant protein (...
Article
Although urinary catheters (UCs) are one of the most used medical devices, they are related to a high incidence of urinary tract infections resulting from microbial colonization and consequent biofilm development on UC surfaces. Currently, a panoply of antimicrobial and antifouling surfaces is available to solve this longstanding problem. However,...
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Protein Engineering is a highly evolved field of engineering aimed at developing proteins for specific industrial, medical, and research applications. Here, we present a practical teaching course to demonstrate fundamental techniques used to express, purify and analyze a recombinant protein produced in Escherichia coli—the enhanced green fluorescen...
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The increasing incidence of implant-associated infections has prompted the development of effective strategies to prevent biofilm formation on these devices. In this work, pristine graphene nanoplatelet/polydimethylsiloxane (GNP/PDMS) surfaces containing different GNP loadings (1, 2, 3, 4, and 5 wt%) were produced and evaluated on their ability to...
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The low efficacy of conventional treatments and the interest in finding natural-based approaches to counteract biofilm development on urinary tract devices have promoted the research on probiotics. This work evaluated the ability of two probiotic strains, Lactobacillus plantarum and Lactobacillus rhamnosus, in displacing pre-formed biofilms of Esch...
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Ureteral stents are broadly used for the treatment of a wide range of pathologies, with different complexities and characteristics. Despite being efficient, the morbidity associated with stents, such as bacterial infection and pain, limits their therapeutic action and often represents an increase in healthcare costs. As no single solution fits all...
Article
Bacterial colonization of indwelling medical devices poses a danger to the patient and is a tremendous economic burden that costs billions of dollars to the healthcare system. Thus, it is essential to develop an effective mechanism that prevents the attachment of bacteria to the surface in combination with bactericidal strategies to kill them in di...
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Despite the advancements in material science and surgical techniques, the incidence of implant-associated infections (IAIs) has increased significantly. IAIs are mainly caused by microbial adhesion and biofilm formation on implant surfaces. In this study, we aimed to evaluate and critically discuss the antimicrobial efficacy of chitosan-based coati...
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The early colonization of surfaces and subsequent biofilm development have severe impacts in environmental, industrial, and biomedical settings since they entail high costs and health risks. To develop more effective biofilm control strategies, there is a need to obtain laboratory biofilms that resemble those found in natural or man-made settings....
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In the present study, the effects of different nutrient media on the development of Escherichia coli biofilms and the production of a heterologous protein were examined. E. coli JM109(DE3) cells transformed with pFM23 plasmid carrying the gene for enhanced green fluorescent protein (eGFP) expression were used. Cells were grown in two different cult...
Chapter
The undesirable attachment of fouling organisms to submerged surfaces occurs spontaneously in marine ecosystems and may have serious economic and environmental implications. Cyanobacteria are one of the most dominant microfoulers, colonizing different surfaces at diverse locations all over the world. Several factors have been indicated as modulator...
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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 evaluat...
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Implantable medical devices (IMDs) are susceptible to microbial adhesion and biofilm formation, which lead to several clinical complications, including the occurrence of implant-associated infections. Polylactic acid (PLA) and its composites are currently used for the construction of IMDs. In addition, chitosan (CS) is a natural polymer that has be...
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The growing requirement for sustainable processes has boosted the development of biodegradable plastic-based materials incorporating bioactive compounds obtained from waste, adding value to these products. Chitosan (Ch) is a biopolymer that can be obtained by deacetylation of chitin (found abundantly in waste from the fishery industry) and has valu...
Article
The development of self-cleaning biomimetic surfaces has the potential to be of great benefit to human health, in addition to reducing the economic burden on industries worldwide. Consequently, this study developed a biomimetic wax surface using a moulding technique which emulated the topography of the self-cleaning Gladiolus hybridus (Gladioli) le...
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Biofilm-related infections are becoming a major clinical problem due to the increasingly widespread ability of pathogens to develop persistent biofilms in medical devices. The inadequate response of conventional antimicrobial strategies to counteract biofilm development demands urgent alternatives. An increasing interest in promoting a natural appr...
Article
Background Urinary stents have been around for the last 4 decades, urinary catheters even longer. They are associated with infections, encrustation, migration and patient discomfort. Research efforts to improve them have shifted onto molecular and cellular levels. ENIUS brought together translational scientists to improve urinary implants and reduc...
Article
Cyanobacterial molecular biology can identify pathways that affect the adhesion and settlement of biofouling organisms and, consequently, obtain novel antifouling strategies for marine applications. Proteomic analyses can provide an essential understanding of how cyanobacteria adapt to different environmental settings. However, only a few qualitati...
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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 sur...
Article
The control of marine biofouling has raised serious environmental concerns, thus the continuous release of toxic and persistent biocidal agents applied as anti-biofouling coatings have triggered the search for non-toxic strategies. However, most of them still lack rigorous evaluation of their ecotoxicity and antifouling effects under real scenarios...
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Several methodologies have been implemented with the intent of preventing or reducing the formation of biofilms on indwelling urinary devices. The use of carbon nanotubes (CNTs) in the biomedical field has been increasing, particularly in the production of antimicrobial and antifouling coatings. Despite their proven antimicrobial properties, their...
Article
Hospital-acquired infections are still a major concern worldwide, being frequently related to bacterial biofilm formation on medical devices, and thus difficult to eradicate with conventional antimicrobial treatments. Therefore, infection-preventive solutions based on natural polymers are being investigated. Recently, a marine cyanobacterium-derive...
Article
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 cyanobacte...
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Full-text available
Bio-contamination of water through biofouling, which involves the natural colonization of submerged surfaces by waterborne organisms, is a global socio-economic concern, allied to premature materials bio-corrosion and high human health risks. Most effective strategies release toxic and persistent disinfectant compounds into the aquatic medium, caus...
Article
Biofilm growth (fouling) in microdevices is a critical concern in several industrial, engineering and health applications, particularly in novel high-performance microdevices often designed with complex geometries, narrow regions and multiple headers. Unfortunately, on these devices, the regions with local high wall shear stresses (WSS) also show h...
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The development of antifouling (AF) technology for marine environments is an area of intense research given the severe economic and ecological effects of marine biofouling. Preliminary data from in vitro assays is frequently used to screen the performance of AF coatings. It is intuitive that microbial composition plays a major role in surface colon...
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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 successfu...
Article
This paper describes the fabrication of antifouling surfaces by the combination of topography and peptide chemistry. The topography of the surface mimics the skin of the shark that can resist biofouling by having a certain microtopography. A peptide-based coating that resists fouling self-assembles on these surfaces. In biofilm formation assays, pe...
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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 sys...
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Intraspecies diversity in biofilm communities is associated with enhanced survival and growth of the individual biofilm populations. Studies on the subject are scarce, namely, when more than three strains are present. Hence, in this study, the influence of intraspecies diversity in biofilm populations composed of up to six different Escherichia col...
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Biofilms formed on submerged marine surfaces play a critical role in the fouling process, causing increased fuel consumption, corrosion, and high maintenance costs. Thus, marine biofouling is a major issue and motivates the development of antifouling coatings. In this study, the performance of two commercial marine coatings, a foul-release silicone...
Article
Cyanobacteria promote marine biofouling with significant impacts. A qualitative proteomic analysis, by LC-MS/MS, of planktonic and biofilm cells from two cyanobacteria was performed. Biofilms were formed on glass and perspex at two relevant hydrodynamic conditions for marine environments (average shear rates of 4 s−1 and 40 s−1). For both strains a...
Article
Full-text available
Different studies have shown that the incorporation of carbon nanotubes (CNTs) into poly(dimethylsiloxane) (PDMS) enables the production of composite materials with enhanced properties, which can find important applications in the biomedical field. In the present work, CNT/PDMS composite materials have been prepared to evaluate the effects of prist...
Article
Full-text available
The aim of this work was to study the initial events of Escherichia coli adhesion to polydimethylsiloxane, which is critical for the development of antifouling surfaces. A parallel plate flow cell was used to perform the initial adhesion experiments under controlled hydrodynamic conditions (shear rates ranging between 8 and 100/s), mimicking biomed...
Article
Infections related to bacterial colonization of medical devices are a growing concern given the socio-economical impacts in healthcare systems. Colonization of a device surface with bacteria usually triggers the development of a biofilm, which is more difficult to eradicate than free-floating or adhered bacteria and can act as a reservoir for subse...
Chapter
PDMS is one of the most widely used polymers for the fabrication of biomedical devices. Of particular relevance is the application of PDMS in urinary tract devices such as urinary catheters and ureteral stents. As these devices are being used by a growing number of patients and indwelling times are increasing in an aging population, the incidence o...
Chapter
Carbon nanotubes (CNTs) are versatile nanomaterials with outstanding properties that can be used in different fields. This chapter reviews the use of single- and multi-walled CNTs in the development of antimicrobial and antifouling surfaces. The performance of CNT-containing surfaces seems to depend on a multiplicity of factors that can be conjugat...
Article
Full-text available
Urinary tract infections are one of the most common hospital-acquired infections, and they are often associated with biofilm formation in indwelling medical devices such as catheters and stents. This study aims to investigate the antibiofilm performance of a polymer brush—poly[oligo(ethylene glycol) methyl ether methacrylate], poly(MeOEGMA)—and eva...
Article
Full-text available
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 cyano...
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This work assesses the effect of chemical induction with isopropyl β-D-1-thiogalactopyranoside (IPTG) on the expression of enhanced green fluorescent protein (eGFP) by planktonic and biofilm cells of Escherichia coli JM109(DE3) transformed with a plasmid containing a T7 promoter. It was shown that induction negatively affected the growth and viabil...
Article
Aim of this study is the development of new functional coatings for medical devices, using magnetron co-sputtering to deposit triple TiO2/SiO2/Ag nanocomposite thin films with expected antimicrobial activity. Some surface characteristics (elemental composition, hydrophilic/hydrophobic balance, surface energy and topography) were estimated to look f...
Article
Marine biofouling has severe economic impacts and cyanobacteria play a significant role as early surface colonizers. Despite this fact, cyanobacterial biofilm formation studies in controlled hydrodynamic conditions are scarce. In this work, computational fluid dynamics was used to determine the shear rate field on coupons that were placed inside th...
Chapter
Research in bacterial biofilms is usually focused on their deleterious effects in the health and industrial sectors. Nevertheless, biofilms are used in wastewater treatment and for the production of valuable compounds since biofilm reactors show many advantages over suspended cell reactors, especially in their higher biomass density and operational...
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Full-text available
Biofilm research is usually focused on the prevention or control of biofilm formation. Recently, the significance of the biofilm mode of growth in biotechnological applications received increased attention. Since biofilm reactors show many advantages over suspended cell reactors, especially in their higher biomass density and operational stability,...
Article
Full-text available
A fabrication method is developed to produce a microfluidic device to test cell adhesion to polymeric materials. The process is able to produce channels with walls of any spin coatable polymer. The method is a modification of the existing poly-dimethylsiloxane soft lithography method and, therefore, it is compatible with sealing methods and equipme...
Article
In Europe, the mean incidence of urinary tract infections in intensive care units is 1.1 per 1000 patient‐days. Of these cases, catheter‐associated urinary tract infections (CAUTI) account for 98%. In total, CAUTI in hospitals is estimated to give additional health‐care costs of £1–2.5 billion in the United Kingdom alone. This is in sharp contrast...
Chapter
Biofilm formation in the food industry is a major concern due to the severe economic impact and associated health risks. This process is strongly affected by hydrodynamics and therefore the knowledge of flow characteristics in different food process areas is crucial for the development of more efficient biofilm control strategies. This development...
Article
Polydimethylsiloxane (PDMS) is widely used as a coating material and in the fabrication of medical implants for the urinary tract and also in biofilm reactors. When this polymer is used in biomedical devices, bacterial adhesion to the surface must be avoided to prevent implant‐related infections, whereas in biofilm reactors, adhesion has to be prom...
Article
In this work, two antifouling polymer brushes were tested at different shear stress conditions to evaluate their performance in reducing the initial adhesion of Escherichia coli. Assays were performed using a parallel plate flow chamber and a shear stress range between 0.005 and 0.056 Pa. These shear stress values can be found in different location...
Article
Biofilms can damage implants and are difficult to treat. Here, we assessed the performance of a tripeptide that self-assembles into an antifouling coating over a broad range of shear conditions that are relevant to biomedical applications. Adhesion assays were performed using a parallel plate flow chamber. The results show that the coating can redu...
Chapter
Biofilms are complex and dynamic communities of surface-attached microorganisms held together by a self-produced extracellular polymeric matrix, forming a highly hydrated structure. It is known that there is considerable heterogeneity within biofilms with respect to local environments, which may result in spatial and temporal patterns of gene expre...
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Full-text available
Recombinant protein production in bacterial cells is commonly performed using planktonic cultures. However, the natural state for many bacteria is living in communities attached to surfaces forming biofilms. In this work, a flow cell system was used to compare the production of a model recombinant protein (enhanced green fluorescent protein, eGFP)...
Article
Escherichia coli typically colonizes food contact surfaces in the presence of other bacterial strains. The aim of this work was to evaluate the influence of a resident strain isolated from a fresh-cut salad industry (Pseudomonas grimontii 13A10) on the development of a model pathogen (E. coli) on bare stainless steel (SST) and stainless steel coate...
Article
Multispecies biofilms represent the dominant mode of life for the vast majority of microorganisms. Bacterial spatial localization in such biostructures governs ecological interactions between different populations and triggers the overall community functions. Here, we discuss the pros and cons of fluorescence-based techniques used to decipher bacte...
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Full-text available
Bacterial adhesion and biofilm formation on food processing surfaces pose major risks to human health. Non-efficient cleaning of equipment surfaces and piping can act as a conditioning layer that affects the development of a new biofilm post-disinfection. We have previously shown that surface conditioning with cell extracts could reduce biofilm for...