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The main goal of this study was to chemically characterize an aqueous S. nigra flower extract and validate it as a bioactive agent. The elderflower aqueous extraction was performed at different temperatures (50, 70 and 90 °C). The extract obtained at 90 °C exhibited the highest phenolic content and antiradical activity. Therefore, this extract was analyzed by GC-MS and HPLC-MS, which allowed the identification of 46 compounds, being quercetin and chlorogenic acid derivatives representative of 86% of the total of phenolic compounds identified in hydrophilic fraction of the aqueous extract. Naringenin (27.2%) was the major compound present in the lipophilic fraction. The antiproliferative effects of the S. nigra extract were evaluated using the colon cancer cell lines RKO, HCT-116, Caco-2 and the extract’s antigenotoxic potential was evaluated by the Comet assay in RKO cells. The RKO cells were the most susceptible to S. nigra flower extract (IC50 = 1250 µg mL−1). Moreover, the extract showed antimicrobial activity against Gram-positive bacteria, particularly Staphylococcus aureus and S. epidermidis. These results show that S. nigra-based extracts can be an important dietary source of bioactive phenolic compounds that contribute to health-span improving life quality, demonstrating their potential as nutraceutical, functional foods and/or cosmetic components for therapeutic purposes.
Pedro Ferreira-Santos; Helder Badim; Ângelo C. Salvador; Armando J. D. Silvestre; Sónia A. O. Santos; Sílvia M. Rocha; Ana M. Sousa; Maria Olívia Pereira; Cristina Pereira Wilson; Cristina M. R. Rocha; José António Teixeira; Cláudia M. Botelho. Chemical Characterization of Sambucus nigra L. Flowers Aqueous Extract and Its Biological Implications. Biomolecules 2021, 11, 1222 .
AMA StylePedro Ferreira-Santos, Helder Badim, Ângelo C. Salvador, Armando J. D. Silvestre, Sónia A. O. Santos, Sílvia M. Rocha, Ana M. Sousa, Maria Olívia Pereira, Cristina Pereira Wilson, Cristina M. R. Rocha, José António Teixeira, Cláudia M. Botelho. Chemical Characterization of Sambucus nigra L. Flowers Aqueous Extract and Its Biological Implications. Biomolecules. 2021; 11 (8):1222.
Chicago/Turabian StylePedro Ferreira-Santos; Helder Badim; Ângelo C. Salvador; Armando J. D. Silvestre; Sónia A. O. Santos; Sílvia M. Rocha; Ana M. Sousa; Maria Olívia Pereira; Cristina Pereira Wilson; Cristina M. R. Rocha; José António Teixeira; Cláudia M. Botelho. 2021. "Chemical Characterization of Sambucus nigra L. Flowers Aqueous Extract and Its Biological Implications." Biomolecules 11, no. 8: 1222.
Aim: To investigate the role of pre-established Staphylococcus aureus on Pseudomonas aeruginosa adaptation and antibiotic tolerance. Materials & methods: Bacteria were cultured mimicking the sequential pattern of lung colonization and exposure to ciprofloxacin. Results: In the absence of ciprofloxacin exposure, S. aureus and P. aeruginosa coexisted supported by the physicochemical characteristics of the artificial sputum medium. S. aureus had no role in P. aeruginosa tolerance against ciprofloxacin and did not select P. aeruginosa small-colony variants during antibiotic treatment. rhlR and psqE were downregulated after the contact with S. aureus indicating that P. aeruginosa attenuated its virulence potential. Conclusion: P. aeruginosa and S. aureus can cohabit in cystic fibrosis airway environment for long-term without significant impact on P. aeruginosa adaptation and antibiotic tolerance.
Rosana Monteiro; Andreia Patrícia Magalhães; Maria Olivia Pereira; Ana Margarida Sousa. Long-term coexistence of Pseudomonas aeruginosa and Staphylococcus aureus using an in vitro cystic fibrosis model. Future Microbiology 2021, 16, 879 -893.
AMA StyleRosana Monteiro, Andreia Patrícia Magalhães, Maria Olivia Pereira, Ana Margarida Sousa. Long-term coexistence of Pseudomonas aeruginosa and Staphylococcus aureus using an in vitro cystic fibrosis model. Future Microbiology. 2021; 16 ():879-893.
Chicago/Turabian StyleRosana Monteiro; Andreia Patrícia Magalhães; Maria Olivia Pereira; Ana Margarida Sousa. 2021. "Long-term coexistence of Pseudomonas aeruginosa and Staphylococcus aureus using an in vitro cystic fibrosis model." Future Microbiology 16, no. : 879-893.
Antimicrobial therapy is facing a worrisome and underappreciated challenge, the phenomenon of heteroresistance (HR). HR has been gradually documented in clinically relevant pathogens (e.g. Pseudomonas aeruginosa, Staphylococcus aureus, Burkholderia spp., Acinetobacter baumannii, Klebsiella pneumoniae, Candida spp.) towards several drugs and is believed to complicate the clinical picture of chronic infections. This type of infections are typically mediated by polymicrobial biofilms, wherein microorganisms inherently display a wide range of physiological states, distinct metabolic pathways, diverging refractory levels of stress responses, and a complex network of chemical signals exchange. This review aims to provide an overview on the relevance, prevalence, and implications of HR in clinical settings. Firstly, related terminologies (e.g. resistance, tolerance, persistence), sometimes misunderstood and overlapped, were clarified. Factors generating misleading HR definitions were also uncovered. Secondly, the recent HR incidences reported in clinically relevant pathogens towards different antimicrobials were annotated. The potential mechanisms underlying such occurrences were further elucidated. Finally, the link between HR and biofilms was discussed. The focus was to recognize the presence of heterogeneous levels of resistance within most biofilms, as well as the relevance of polymicrobial biofilms in chronic infectious diseases and their role in resistance spreading. These topics were subject of a critical appraisal, gaining insights into the ascending clinical implications of HR in antimicrobial resistance spreading, which could ultimately help designing effective therapeutic options.
Susana Patrícia Lopes; Paula Jorge; Ana Margarida Sousa; Maria Olívia Pereira. Discerning the role of polymicrobial biofilms in the ascent, prevalence, and extent of heteroresistance in clinical practice. Critical Reviews in Microbiology 2021, 47, 162 -191.
AMA StyleSusana Patrícia Lopes, Paula Jorge, Ana Margarida Sousa, Maria Olívia Pereira. Discerning the role of polymicrobial biofilms in the ascent, prevalence, and extent of heteroresistance in clinical practice. Critical Reviews in Microbiology. 2021; 47 (2):162-191.
Chicago/Turabian StyleSusana Patrícia Lopes; Paula Jorge; Ana Margarida Sousa; Maria Olívia Pereira. 2021. "Discerning the role of polymicrobial biofilms in the ascent, prevalence, and extent of heteroresistance in clinical practice." Critical Reviews in Microbiology 47, no. 2: 162-191.
Fabric structures are prone to contamination with microorganisms, as their morphology and ability to retain moisture creates a proper environment for their growth. In this work, a novel, easily processed and cheap coating for a nylon fabric with antimicrobial characteristics was developed. After plasma treatment, made to render the fabric surface more reactive sites, the fabric was impregnated with chitosan and silver nanoparticles by simply dipping it into a mixture of different concentrations of both components. Silver nanoparticles were previously synthesized using the Lee–Meisel method, and their successful obtention was proven by UV–Vis, showing the presence of the surface plasmon resonance band at 410 nm. Nanoparticles with 25 nm average diameter observed by STEM were stable, mainly in the presence of chitosan, which acted as a surfactant for silver nanoparticles, avoiding their aggregation. The impregnated fabric possessed bactericidal activity higher for Gram-positive Staphylococcus aureus than for Gram-negative Pseudomonas aeruginosa bacteria for all combinations. The percentage of live S. aureus and P. aeruginosa CFU was reduced to less than 20% and 60%, respectively, when exposed to each of the coating combinations. The effect was more pronounced when both chitosan and silver were present in the coating, suggesting an effective synergy between these components. After a washing process, the antimicrobial effect was highly reduced, suggesting that the coating is unstable after washing, being almost completely removed from the fabric. Nevertheless, the new-coated fabric can be successfully used in single-use face masks. To our knowledge, the coating of nylon fabrics intended for face-mask material with both agents has never been reported.
Cláudia M. Botelho; Margarida M. Fernandes; Jefferson M. Souza; Nicolina Dias; Ana M. Sousa; José A. Teixeira; Raul Fangueiro; Andrea Zille. New Textile for Personal Protective Equipment—Plasma Chitosan/Silver Nanoparticles Nylon Fabric. Fibers 2021, 9, 3 .
AMA StyleCláudia M. Botelho, Margarida M. Fernandes, Jefferson M. Souza, Nicolina Dias, Ana M. Sousa, José A. Teixeira, Raul Fangueiro, Andrea Zille. New Textile for Personal Protective Equipment—Plasma Chitosan/Silver Nanoparticles Nylon Fabric. Fibers. 2021; 9 (1):3.
Chicago/Turabian StyleCláudia M. Botelho; Margarida M. Fernandes; Jefferson M. Souza; Nicolina Dias; Ana M. Sousa; José A. Teixeira; Raul Fangueiro; Andrea Zille. 2021. "New Textile for Personal Protective Equipment—Plasma Chitosan/Silver Nanoparticles Nylon Fabric." Fibers 9, no. 1: 3.
Cystic fibrosis (CF) disease provokes the accumulation of thick and viscous sputum in the lungs, favoring the development of chronic and polymicrobial infections. Pseudomonas aeruginosa is the main bacterium responsible for these chronic infections, and much of the difficulty involved in eradicating it is due to biofilm formation. However, this could be mitigated using adjuvant compounds that help or potentiate the antibiotic action. Therefore, the main goal of this study was to search for substances that function as adjuvants and also as biofilm-controlling compounds, preventing or dismantling P. aeruginosa biofilms formed in an in vitro CF airway environment. Dual combinations of compounds with subinhibitory (1 and 2 mg/L) and inhibitory concentrations (4 mg/L) of ciprofloxacin were tested to inhibit the bacterial growth and biofilm formation (prophylactic approach) and to eradicate 24-h-old P. aeruginosa populations, including planktonic cells and biofilms (treatment approach). Our results revealed that aspartic acid (Asp) and succinic acid (Suc) restored ciprofloxacin action against P. aeruginosa. Suc combined with 2 mg/L of ciprofloxacin (Suc-Cip) was able to eradicate bacteria, and Asp combined with 4 mg/L of ciprofloxacin (Asp–Cip) seemed to eradicate the whole 24-h-old populations, including planktonic cells and biofilms. Based on biomass depletion data, we noted that Asp induced cell death and Suc seemed somehow to block or reduce the expression of ciprofloxacin resistance. As far as we know, this kind of action had not been reported up till now. The presence of Staphylococcus aureus and Burkholderia cenocepacia did not affect the efficacy of the Asp–Cip and Suc–Cip therapies against P. aeruginosa and, also important, P. aeruginosa depletion from polymicrobial communities did not create a window of opportunity for these species to thrive. Rather the contrary, Asp and Suc also improved ciprofloxacin action against B. cenocepacia. Further studies on the cytotoxicity using lung epithelial cells indicated toxicity of Suc–Cip caused by the Suc. In conclusion, we provided evidences that Asp and Suc could be potential ciprofloxacin adjuvants to eradicate P. aeruginosa living within polymicrobial communities. Asp–Cip and Suc–Cip could be promising therapeutic options to cope with CF treatment failures.
Eduarda Silva; Rosana Monteiro; Tânia Grainha; Diana Alves; Maria Olivia Pereira; Ana Margarida Sousa. Fostering Innovation in the Treatment of Chronic Polymicrobial Cystic Fibrosis-Associated Infections Exploring Aspartic Acid and Succinic Acid as Ciprofloxacin Adjuvants. Frontiers in Cellular and Infection Microbiology 2020, 10, 1 .
AMA StyleEduarda Silva, Rosana Monteiro, Tânia Grainha, Diana Alves, Maria Olivia Pereira, Ana Margarida Sousa. Fostering Innovation in the Treatment of Chronic Polymicrobial Cystic Fibrosis-Associated Infections Exploring Aspartic Acid and Succinic Acid as Ciprofloxacin Adjuvants. Frontiers in Cellular and Infection Microbiology. 2020; 10 ():1.
Chicago/Turabian StyleEduarda Silva; Rosana Monteiro; Tânia Grainha; Diana Alves; Maria Olivia Pereira; Ana Margarida Sousa. 2020. "Fostering Innovation in the Treatment of Chronic Polymicrobial Cystic Fibrosis-Associated Infections Exploring Aspartic Acid and Succinic Acid as Ciprofloxacin Adjuvants." Frontiers in Cellular and Infection Microbiology 10, no. : 1.
Worldwide, infections are resuming their role as highly effective killing diseases, as current treatments are failing to respond to the growing problem of antimicrobial resistance (AMR). The social and economic burden of AMR seems ever rising, with health- and research-related organizations rushing to collaborate on a worldwide scale to find effective solutions. Resistant bacteria are spreading even in first-world nations, being found not only in healthcare-related settings, but also in food and in the environment. In this minireview, the impact of AMR in healthcare systems and the major bacteria behind it are highlighted. Ecological aspects of AMR evolution and the complexity of its molecular mechanisms are explained. Major concepts, such as intrinsic, acquired and adaptive resistance, as well as tolerance and heteroresistance, are also clarified. More importantly, the problematic of biofilms and their role in AMR, namely their main resistance and tolerance mechanisms, are elucidated. Finally, some of the most promising anti-biofilm strategies being investigated are reviewed. Much is still to be done regarding the study of AMR and the discovery of new anti-biofilm strategies. Gladly, considerable research on this topic is generated every day and increasingly concerted actions are being engaged globally to try and tackle this problem.
Paula Jorge; Andreia Patricia Magalhães; Tânia Grainha; Diana Alves; Ana Margarida Sousa; Susana Lopes; Maria Olívia Pereira. Antimicrobial resistance three ways: healthcare crisis, major concepts and the relevance of biofilms. FEMS Microbiology Ecology 2019, 95, 1 .
AMA StylePaula Jorge, Andreia Patricia Magalhães, Tânia Grainha, Diana Alves, Ana Margarida Sousa, Susana Lopes, Maria Olívia Pereira. Antimicrobial resistance three ways: healthcare crisis, major concepts and the relevance of biofilms. FEMS Microbiology Ecology. 2019; 95 (8):1.
Chicago/Turabian StylePaula Jorge; Andreia Patricia Magalhães; Tânia Grainha; Diana Alves; Ana Margarida Sousa; Susana Lopes; Maria Olívia Pereira. 2019. "Antimicrobial resistance three ways: healthcare crisis, major concepts and the relevance of biofilms." FEMS Microbiology Ecology 95, no. 8: 1.
Pseudomonas aeruginosa chronic infections are the major cause of high morbidity and mortality in cystic fibrosis (CF) patients due to the use of sophisticated mechanisms of adaptation, including clonal diversification into specialized CF-adapted phenotypes. In contrast to chronic infections, very little is known about what occurs after CF lungs colonization and at early infection stages. This study aims to investigate the early events of P. aeruginosa adaptation to CF environment, in particular, to inspect the occurrence of clonal diversification at early stages of infection development and its impact on antibiotherapy effectiveness. To mimic CF early infections, three P. aeruginosa strains were long-term grown in artificial sputum (ASM) over 10 days and phenotypic diversity verified through colony morphology characterization. Biofilm sub- and inhibitory concentrations of ciprofloxacin were applied to non- and diversified populations to evaluate antibiotic effectiveness on P. aeruginosa eradication. Our results demonstrated that clonal diversification might occur after ASM colonization and growth. However, this phenotypic diversification did not compromise ciprofloxacin efficacy in P. aeruginosa eradication since a biofilm minimal inhibitory dosage would be applied. The expected absence of mutators in P. aeruginosa populations led us to speculate that clonal diversification in the absence of ciprofloxacin treatments could to be driven by niche specialization. Yet, biofilm sub-inhibitory concentrations of ciprofloxacin seemed to overlap niche specialization as “fitter” variants had emerged, such as mucoid, small colony and pinpoint variants, known to be highly resistant to antibiotics. The pathogenic potential of all emergent colony morphotypes-associated bacteria, distinct from the wild-morphotypes, revealed that P. aeruginosa evolves to a non-swimming phenotype. Impaired swimming motility seemed to be one of the first evolutionary steps of P. aeruginosa in CF lungs that could pave the way for further adaptation steps including biofilm formation and progress to chronic infection. Based on our findings, impaired swimming motility seemed to be a candidate to disease marker of P. aeruginosa infection development. Despite our in vitro CF model represents a step forward towards in vivo scenario and it provided valuable insights about the early events, more and distinct P. aeruginosa strains should be studied to strengthen our results.
Ana Margarida Sousa; Rosana Monteiro; Maria Olívia Pereira. Unveiling the early events of Pseudomonas aeruginosa adaptation in cystic fibrosis airway environment using a long-term in vitro maintenance. International Journal of Medical Microbiology 2018, 308, 1053 -1064.
AMA StyleAna Margarida Sousa, Rosana Monteiro, Maria Olívia Pereira. Unveiling the early events of Pseudomonas aeruginosa adaptation in cystic fibrosis airway environment using a long-term in vitro maintenance. International Journal of Medical Microbiology. 2018; 308 (8):1053-1064.
Chicago/Turabian StyleAna Margarida Sousa; Rosana Monteiro; Maria Olívia Pereira. 2018. "Unveiling the early events of Pseudomonas aeruginosa adaptation in cystic fibrosis airway environment using a long-term in vitro maintenance." International Journal of Medical Microbiology 308, no. 8: 1053-1064.
Escherichia coli has developed sophisticated means to sense, respond, and adapt in stressed environment. It has served as a model organism for studies in molecular genetics and physiology since the 1960s. Stress response genes are induced whenever a cell needs to adapt and survive under unfavorable growth conditions. Two of the possible important genes are rpoS and bolA. The rpoS gene has been known as the alternative sigma (σ) factor, which controls the expression of a large number of genes, which are involved in responses to various stress factors as well as transition to stationary phase from exponential form of growth. Morphogene bolA response to stressed environment leads to round morphology of E. coli cells, but little is known about its involvement in biofilms and its development or maintenance. This study has been undertaken to address the adherence pattern and formation of biofilms by E. coli on stainless steel, polypropylene, and silicone surfaces after 24 h of growth at 37 °C. Scanning electron microscopy was used for direct examination of the cell attachment and biofilm formation on various surfaces and it was found that, in the presence of bolA, E. coli cells were able to attach to the stainless steel and silicone very well. By contrast, polypropylene surface was not found to be attractive for E. coli cells. This indicates that bolA responded and can play a major role in the presence and absence of rpoS in cell attachment.
Mohd Adnan; Ana Margarida Sousa; Idalina Machado; Maria Olivia Pereira; Saif Khan; Glyn Morton; Sibte Hadi. Role of bolA and rpoS genes in biofilm formation and adherence pattern by Escherichia coli K-12 MG1655 on polypropylene, stainless steel, and silicone surfaces. Acta Microbiologica et Immunologica Hungarica 2017, 64, 179 -189.
AMA StyleMohd Adnan, Ana Margarida Sousa, Idalina Machado, Maria Olivia Pereira, Saif Khan, Glyn Morton, Sibte Hadi. Role of bolA and rpoS genes in biofilm formation and adherence pattern by Escherichia coli K-12 MG1655 on polypropylene, stainless steel, and silicone surfaces. Acta Microbiologica et Immunologica Hungarica. 2017; 64 (2):179-189.
Chicago/Turabian StyleMohd Adnan; Ana Margarida Sousa; Idalina Machado; Maria Olivia Pereira; Saif Khan; Glyn Morton; Sibte Hadi. 2017. "Role of bolA and rpoS genes in biofilm formation and adherence pattern by Escherichia coli K-12 MG1655 on polypropylene, stainless steel, and silicone surfaces." Acta Microbiologica et Immunologica Hungarica 64, no. 2: 179-189.
The emergence of Klebsiella pneumoniae multidrug-resistant strains paves the way to the re-introduction of colistin as a salvage therapy. However, recent planktonic studies have reported several cases of heteroresistance to this antimicrobial agent. The aim of this present work was to gain better understanding about the response of K. pneumoniae biofilms to colistin antibiotherapy and inspect the occurrence of heteroresistance in biofilm-derived cells. Biofilm formation and its susceptibility to colistin were evaluated through the determination of biofilm-cells viability. The profiling of planktonic and biofilm cell populations was conducted to assess the occurrence of heteroresistance. Colony morphology was further characterized in order to inspect the potential role of colistin in K. pneumoniae phenotypic differentiation. Results show that K. pneumoniae was susceptible to colistin in its planktonic form, but biofilms presented enhanced resistance. Population analysis profiles pointed out that K. pneumoniae manifest heteroresistance to colistin only when grown in biofilm arrangements, and it was possible to identify a resistant sub-population presenting a small colony morphology (diameter around 5 mm). To the best of our knowledge, this is the first report linking heteroresistance to biofilm formation and a morphological distinctive sub-population. Moreover, this is the first evidence that biofilm formation can trigger the emergence of heteroresistance in an apparently susceptible strain.
Ana Silva; Ana Margarida Sousa; Diana Alves; Anália Lourenço; Maria Olívia Pereira. Heteroresistance to colistin inKlebsiella pneumoniaeis triggered by small colony variants sub-populations within biofilms. Pathogens and Disease 2016, 74, ftw036 .
AMA StyleAna Silva, Ana Margarida Sousa, Diana Alves, Anália Lourenço, Maria Olívia Pereira. Heteroresistance to colistin inKlebsiella pneumoniaeis triggered by small colony variants sub-populations within biofilms. Pathogens and Disease. 2016; 74 (5):ftw036.
Chicago/Turabian StyleAna Silva; Ana Margarida Sousa; Diana Alves; Anália Lourenço; Maria Olívia Pereira. 2016. "Heteroresistance to colistin inKlebsiella pneumoniaeis triggered by small colony variants sub-populations within biofilms." Pathogens and Disease 74, no. 5: ftw036.
One of the major concerns of the biomedical community is the increasing prevalence of antimicrobial resistant microorganisms. Recent findings show that the diversification of colony morphology may be indicative of the expression of virulence factors and increased resistance to antibiotic therapeutics. To transform these findings, and upcoming results, into a valuable clinical decision making tool, colony morphology characterisation should be standardised. Notably, it is important to establish the minimum experimental information necessary to contextualise the environment that originated the colony morphology, and describe the main morphological features associated unambiguously.This paper presents MorphoCol, a new ontology-based tool for the standardised, consistent and machine-interpretable description of the morphology of colonies formed by human pathogenic bacteria. The Colony Morphology Ontology (CMO) is the first controlled vocabulary addressing the specificities of the morphology of clinically significant bacteria, whereas the MorphoCol publicly Web-accessible knowledgebase is an end-user means to search and compare CMO annotated colony morphotypes. Its ultimate aim is to help correlate the morphological alterations manifested by colony-forming bacteria during infection with their response to the antimicrobial treatments administered.MorphoCol is the first tool to address bacterial colony morphotyping systematically and deliver a free of charge resource to the community. Hopefully, it may introduce interesting features of analysis on pathogenic behaviour and play a significant role in clinical decision making.http://morphocol.org.
Ana Margarida Sousa; Maria Olívia Pereira; Anália Lourenço. MorphoCol: An ontology-based knowledgebase for the characterisation of clinically significant bacterial colony morphologies. Journal of Biomedical Informatics 2015, 55, 55 -63.
AMA StyleAna Margarida Sousa, Maria Olívia Pereira, Anália Lourenço. MorphoCol: An ontology-based knowledgebase for the characterisation of clinically significant bacterial colony morphologies. Journal of Biomedical Informatics. 2015; 55 ():55-63.
Chicago/Turabian StyleAna Margarida Sousa; Maria Olívia Pereira; Anália Lourenço. 2015. "MorphoCol: An ontology-based knowledgebase for the characterisation of clinically significant bacterial colony morphologies." Journal of Biomedical Informatics 55, no. : 55-63.
Biofilm studies are at the crossroads of Biology, Chemistry, Medicine, Material Science and Engineering, among other fields. Data harmonisation in Biofilms is therefore crucial to allow for researchers to collaborate, interchange, understand, and replicate studies at an inter-laboratory and inter-domain scale. The international Minimum Information About a Biofilms Experiment initiative has prepared a set of guidelines for documenting biofilms experiments and data, namely the minimum information checklist. This paper goes a step forward and describes a new ontology for the broad description of biofilm experiments and data. In such an interdisciplinary context we chose to rely on a common integration framework provided by a foundational ontology that facilitates the addition and extension of various sub-domain modules, and the consistent integration of terminology extracted from several existing ontologies, e.g. EXPO and ChEBI. The community is participating actively in the production of this resource, and it is already used by public biofilms-centred databases, such as BiofOmics, and bioinformatics tools, such as the Biofilms Experiment Workbench. This practical validation serves the purpose of disseminating the controlled vocabulary among researchers and identifying current limitations, glitches, and inconsistencies. Information branches will be added, extended or refactored according to user feedback and group discussions.
Ana Margarida Sousa; Maria Olívia Pereira; Nuno F Azevedo; Anália Lourenço. An harmonised vocabulary for communicating and interchanging biofilms experimental results. Journal of Integrative Bioinformatics 2014, 11, 1 .
AMA StyleAna Margarida Sousa, Maria Olívia Pereira, Nuno F Azevedo, Anália Lourenço. An harmonised vocabulary for communicating and interchanging biofilms experimental results. Journal of Integrative Bioinformatics. 2014; 11 (3):1.
Chicago/Turabian StyleAna Margarida Sousa; Maria Olívia Pereira; Nuno F Azevedo; Anália Lourenço. 2014. "An harmonised vocabulary for communicating and interchanging biofilms experimental results." Journal of Integrative Bioinformatics 11, no. 3: 1.
Pseudomonas aeruginosa is the most prevalent pathogen of cystic fibrosis (CF) lung disease. Its long persistence in CF airways is associated with sophisticated mechanisms of adaptation, including biofilm formation, resistance to antibiotics, hypermutability and customized pathogenicity in which virulence factors are expressed according the infection stage. CF adaptation is triggered by high selective pressure of inflamed CF lungs and by antibiotic treatments. Bacteria undergo genetic, phenotypic, and physiological variations that are fastened by the repeating interplay of mutation and selection. During CF infection development, P. aeruginosa gradually shifts from an acute virulent pathogen of early infection to a host-adapted pathogen of chronic infection. This paper reviews the most common changes undergone by P. aeruginosa at each stage of infection development in CF lungs. The comprehensive understanding of the adaptation process of P. aeruginosa may help to design more effective antimicrobial treatments and to identify new targets for future drugs to prevent the progression of infection to chronic stages.
Ana Margarida Sousa; Maria Olívia Pereira. Pseudomonas aeruginosa Diversification during Infection Development in Cystic Fibrosis Lungs—A Review. Pathogens 2014, 3, 680 -703.
AMA StyleAna Margarida Sousa, Maria Olívia Pereira. Pseudomonas aeruginosa Diversification during Infection Development in Cystic Fibrosis Lungs—A Review. Pathogens. 2014; 3 (3):680-703.
Chicago/Turabian StyleAna Margarida Sousa; Maria Olívia Pereira. 2014. "Pseudomonas aeruginosa Diversification during Infection Development in Cystic Fibrosis Lungs—A Review." Pathogens 3, no. 3: 680-703.
The minimum information about a biofilm experiment (MIABiE) initiative has arisen from the need to find an adequate and scientifically sound way to control the quality of the documentation accompanying the public deposition of biofilm-related data, particularly those obtained using high-throughput devices and techniques. Thereby, the MIABiE consortium has initiated the identification and organization of a set of modules containing the minimum information that needs to be reported to guarantee the interpretability and independent verification of experimental results and their integration with knowledge coming from other fields. MIABiE does not intend to propose specific standards on how biofilms experiments should be performed, because it is acknowledged that specific research questions require specific conditions which may deviate from any standardization. Instead, MIABiE presents guidelines about the data to be recorded and published in order for the procedure and results to be easily and unequivocally interpreted and reproduced. Overall, MIABiE opens up the discussion about a number of particular areas of interest and attempts to achieve a broad consensus about which biofilm data and metadata should be reported in scientific journals in a systematic, rigorous and understandable manner.
Anália Lourenço; Tom Coenye; Darla M. Goeres; Gianfranco Donelli; Andreia Sofia Azevedo; Howard Ceri; Filipa L. Coelho; Hans-Curt Flemming; Talis Juhna; Susana Lopes; Rosário Oliveira; Antonio Oliver; Mark Shirtliff; Ana Margarida Sousa; Paul Stoodley; Maria Olivia Pereira; Nuno Azevedo. Minimum information about a biofilm experiment (MIABiE): standards for reporting experiments and data on sessile microbial communities living at interfaces. Pathogens and Disease 2014, 70, 250 -256.
AMA StyleAnália Lourenço, Tom Coenye, Darla M. Goeres, Gianfranco Donelli, Andreia Sofia Azevedo, Howard Ceri, Filipa L. Coelho, Hans-Curt Flemming, Talis Juhna, Susana Lopes, Rosário Oliveira, Antonio Oliver, Mark Shirtliff, Ana Margarida Sousa, Paul Stoodley, Maria Olivia Pereira, Nuno Azevedo. Minimum information about a biofilm experiment (MIABiE): standards for reporting experiments and data on sessile microbial communities living at interfaces. Pathogens and Disease. 2014; 70 (3):250-256.
Chicago/Turabian StyleAnália Lourenço; Tom Coenye; Darla M. Goeres; Gianfranco Donelli; Andreia Sofia Azevedo; Howard Ceri; Filipa L. Coelho; Hans-Curt Flemming; Talis Juhna; Susana Lopes; Rosário Oliveira; Antonio Oliver; Mark Shirtliff; Ana Margarida Sousa; Paul Stoodley; Maria Olivia Pereira; Nuno Azevedo. 2014. "Minimum information about a biofilm experiment (MIABiE): standards for reporting experiments and data on sessile microbial communities living at interfaces." Pathogens and Disease 70, no. 3: 250-256.
The description of biofilm features presents a conceptual and practical challenge. Biofilm studies often encompass multidisciplinary approaches from Biology, Chemistry, Medicine, Material Science and Engineering, among other fields. Standardising biofilm data is essential to be able to accomplish large-scale collaborative and complementary analysis. To define a common standard format to exchange the heterogeneous biofilm data, it is first necessary to define a set of minimum information for the documentation of biofilm experiments. Then, data should be organised and semantically integrated. This paper describes the first ontology designed to share structured vocabulary for the annotation of the general biofilm experimental workflow – the Biofilm Ontology (BO). This ontology is intended for the broad research community, including bench microbiologists, clinical researchers, clinicians, curators and bioinformaticians.
Ana Margarida Sousa; Maria Olívia Pereira; Nuno F. Azevedo; Anália Lourenço. Designing an Ontology Tool for the Unification of Biofilms Data. Advances in Intelligent Systems and Computing 2014, 41 -48.
AMA StyleAna Margarida Sousa, Maria Olívia Pereira, Nuno F. Azevedo, Anália Lourenço. Designing an Ontology Tool for the Unification of Biofilms Data. Advances in Intelligent Systems and Computing. 2014; ():41-48.
Chicago/Turabian StyleAna Margarida Sousa; Maria Olívia Pereira; Nuno F. Azevedo; Anália Lourenço. 2014. "Designing an Ontology Tool for the Unification of Biofilms Data." Advances in Intelligent Systems and Computing , no. : 41-48.
Colony morphology may be an indicator of phenotypic variation, this being an important adaptive process adopted by bacteria to overcome environmental stressors. Furthermore, alterations in colony traits may reflect increased virulence and antimicrobial resistance. Despite the potential relevance of using colony morphological traits, the influence of experimental conditions on colony morphogenesis has been scarcely studied in detail. This study aims to clear and systematically at demonstrating the impact of some variables, such as colony growth time, plate colony density, culture medium, planktonic or biofilm mode of growth and strains genetic background, on bacterial colony morphology features using two P. aeruginosa strains. Results, based on 5-replicate experiments, demonstrated that all variables influenced colony morphogenesis and 18 different morphotypes were identified, showing different sizes, forms, colours, textures and margins. Colony growth time and composition of the medium were the variables that caused the highest impact on colony differentiation both derived from planktonic and biofilm cultures. Colony morphology characterization before 45 h of incubation was considered inadequate and TSA, a non-selective medium, provided more colony diversity in contrast to P. aeruginosa selective media. In conclusion, data obtained emphasized the need to perform comparisons between colony morphologies in equivalent experimental conditions to avoid misinterpretation of microbial diagnostics and biomedical studies. Since colony morphotyping showed to be a reliable method to evaluate phenotypic switching and also to infer about bacterial diversity in biofilms, these unambiguous comparisons between morphotypes may offer a quite valuable input to clinical diagnosis, aiding the decision-making towards the selection of the most suitable antibiotic and supportive treatments
Ana Margarida Sousa; Idalina Machado; Ana Nicolau; Maria Olivia Pereira. Improvements on colony morphology identification towards bacterial profiling. Journal of Microbiological Methods 2013, 95, 327 -335.
AMA StyleAna Margarida Sousa, Idalina Machado, Ana Nicolau, Maria Olivia Pereira. Improvements on colony morphology identification towards bacterial profiling. Journal of Microbiological Methods. 2013; 95 (3):327-335.
Chicago/Turabian StyleAna Margarida Sousa; Idalina Machado; Ana Nicolau; Maria Olivia Pereira. 2013. "Improvements on colony morphology identification towards bacterial profiling." Journal of Microbiological Methods 95, no. 3: 327-335.
Matrix assisted laser desorption ionization time of flight mass spectrometry has been explored as a tool to bacterial colony morphotyping.To this end,four colony morphotypes of Pseudomonas aeruginosa and four of Staphylococcus aureus were analysed using intact bacteria.Results suggest that mass spectrometry of intact bacteria could,in some extent,be used to complement the classical morphological classification of bacteria.Financial support from IBB-CEB and Fundacao para a Ciencia e Tecnologia (FCT) and European Community fund FEDER, through Program COMPETE, in the ambit of the FCT project "PTDC/SAU-SAP/113196/2009/ FCOMP-01-0124-FEDER-016012" and Ana Margarida Sousa PhD grant (SFRH/BD/72551/2010), is gratefully acknowledged. Authors also thank Portugal-Spain cooperation action sponsored by the Foundation of Portuguese Universities [E 48/11] and the Spanish Ministry of Science and Innovation [AIB2010PT-00353]
Ana Margarida Sousa; J.D. Nunes-Miranda; Miguel Reboiro-Jato; Florentino Fdez-Riverola; Anália Lourenço; Maria Olivia Pereira; J.L. Capelo. A new approach to bacterial colony morphotyping by matrix-assisted laser desorption ionization time of flight-based mass spectrometry. Talanta 2013, 116, 100 -107.
AMA StyleAna Margarida Sousa, J.D. Nunes-Miranda, Miguel Reboiro-Jato, Florentino Fdez-Riverola, Anália Lourenço, Maria Olivia Pereira, J.L. Capelo. A new approach to bacterial colony morphotyping by matrix-assisted laser desorption ionization time of flight-based mass spectrometry. Talanta. 2013; 116 ():100-107.
Chicago/Turabian StyleAna Margarida Sousa; J.D. Nunes-Miranda; Miguel Reboiro-Jato; Florentino Fdez-Riverola; Anália Lourenço; Maria Olivia Pereira; J.L. Capelo. 2013. "A new approach to bacterial colony morphotyping by matrix-assisted laser desorption ionization time of flight-based mass spectrometry." Talanta 116, no. : 100-107.
Pathogenicity, virulence and resistance of infection-causing bacteria are noteworthy problems in clinical settings, even after disinfection practices and antibiotic courses. Although it is common knowledge that these traits are associated to phenotypic and genetic variations, recent studies indicate that colony morphology variations are a sign of increased bacterial resistance to antimicrobial agents (i.e. antibiotics and disinfectants) and altered virulence and persistence.
Ana Margarida Sous; Anália Lourenço; Maria Olívia Pereira. MorphoCol: A Powerful Tool for the Clinical Profiling of Pathogenic Bacteria. Advances in Intelligent and Soft Computing 2012, 154, 181 -188.
AMA StyleAna Margarida Sous, Anália Lourenço, Maria Olívia Pereira. MorphoCol: A Powerful Tool for the Clinical Profiling of Pathogenic Bacteria. Advances in Intelligent and Soft Computing. 2012; 154 ():181-188.
Chicago/Turabian StyleAna Margarida Sous; Anália Lourenço; Maria Olívia Pereira. 2012. "MorphoCol: A Powerful Tool for the Clinical Profiling of Pathogenic Bacteria." Advances in Intelligent and Soft Computing 154, no. : 181-188.
Antimicrobial residue deposition can change the physico-chemical properties of bacteria and surfaces and thus promote or impair bacterial adhesion. This study focuses on benzalkonium chloride (BC) deposition on polystyrene (PS) surfaces and the influence of this conditioning film on the physico-chemical properties of PS and on early adhesion and biofilm formation by Pseudomonas aeruginosa wild-type and its laboratory BC-adapted strain. The latter readily acquired the ability to grow in BC, and also exhibited physico-chemical surface changes. The existence of residues on PS surfaces altered their hydrophobicity and favoured adhesion as determined by the free energy and early adhesion characterization. Adapted bacteria revealed a higher ability to adhere to surfaces and to develop biofilms, especially on BC-conditioned surfaces, which thereby could enhance resistance to sanitation attempts. These findings highlight the importance of investigations concerning the antimicrobial deposition effect after cleaning procedures, which may encourage bacterial adhesion, especially of bacteria that have been previously exposed to chemical stresses.
Idalina Machado; Joana Graça; Ana Margarida Sousa; Susana Patrícia Lopes; Maria Olivia Pereira. Effect of antimicrobial residues on early adhesion and biofilm formation by wild-type and benzalkonium chloride-adaptedPseudomonas aeruginosa. Biofouling 2011, 27, 1151 -1159.
AMA StyleIdalina Machado, Joana Graça, Ana Margarida Sousa, Susana Patrícia Lopes, Maria Olivia Pereira. Effect of antimicrobial residues on early adhesion and biofilm formation by wild-type and benzalkonium chloride-adaptedPseudomonas aeruginosa. Biofouling. 2011; 27 (10):1151-1159.
Chicago/Turabian StyleIdalina Machado; Joana Graça; Ana Margarida Sousa; Susana Patrícia Lopes; Maria Olivia Pereira. 2011. "Effect of antimicrobial residues on early adhesion and biofilm formation by wild-type and benzalkonium chloride-adaptedPseudomonas aeruginosa." Biofouling 27, no. 10: 1151-1159.
The main goal of this work was to examine whether the continuous exposure of single and binary P. aeruginosa and E. coli biofilms to sub‐lethal benzalkonium chloride (BC) doses can induce adaptive response of bacteria. Biofilms were formed during 24 h and then put continuously in contact with BC for more 5 days. The six‐day‐old adapted biofilms were then submitted to BC challenge, characterized and inspected by SEM. Both single and binary adapted biofilms have clearly more biomass, polysaccharides and proteins and less activity even though the number of cells was identical. After BC treatment, adapted biofilms maintained their mass and activity. SEM examination revealed that those adapted biofilms had a slimier and denser matrix that became thicker after BC treatment. Continuous exposure of bacteria to antimicrobials can lead to development of biofilms encompassing more virulent and tolerant bacteria. This adaptive resistance can be the result of a phenotypic adaptation, a genetic acquired resistance or both. Instead of eradicating biofilms and kill microorganisms, the use of a disinfectant can, favour biofilm formation and tolerance. This must be a genuine concern as it can happen in clinical environments, where the use of antimicrobials is unavoidable. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Idalina Machado; Susana Lopes; Ana Margarida Sousa; Maria Olívia Pereira. Adaptive response of single and binary Pseudomonas aeruginosa and Escherichia coli biofilms to benzalkonium chloride. Journal of Basic Microbiology 2011, 52, 43 -52.
AMA StyleIdalina Machado, Susana Lopes, Ana Margarida Sousa, Maria Olívia Pereira. Adaptive response of single and binary Pseudomonas aeruginosa and Escherichia coli biofilms to benzalkonium chloride. Journal of Basic Microbiology. 2011; 52 (1):43-52.
Chicago/Turabian StyleIdalina Machado; Susana Lopes; Ana Margarida Sousa; Maria Olívia Pereira. 2011. "Adaptive response of single and binary Pseudomonas aeruginosa and Escherichia coli biofilms to benzalkonium chloride." Journal of Basic Microbiology 52, no. 1: 43-52.