Percorrer por autor "Bessa, Lucinda J."
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- Boosting cosmeceutical peptides : coupling Imidazolium-based ionic liquids to pentapeptide-4 originates new leads with antimicrobial and collagenesis-inducing activitiesPublication . Gomes, Ana; Bessa, Lucinda J.; Fernandes, Iva; Aguiar, Luísa; Ferraz, Ricardo; Monteiro, Cláudia; Martins, M. Cristina L.; Mateus, Nuno; Gameiro, Paula; Teixeira, Cátia; Gomes, PaulaFollowing our previous reports on dual-action antibacterial and collagenesis-inducing hybrid peptide constructs based on “pentapeptide-4” (PP4, with amino acid sequence KTTKS), whose N-palmitoyl derivative is the well-known cosmeceutical ingredient Matrixyl, herein we disclose novel ionic liquid/PP4 conjugates (IL-KTTKS). These conjugates present potent activity against either antibiotic-susceptible strains or multidrug resistant clinical isolates of both Gram-positive and Gram-negative bacterial species belonging to the so-called “ESKAPE” group of pathogens. Noteworthy, their antibacterial activity is preserved in simulated wound fluid, which anticipates an effective action in the setting of a real wound bed. Moreover, their collagenesis-inducing effects in vitro are comparable to or stronger than those of Matrixyl. Altogether, IL-KTTKS exert a triple antibacterial, antifungal, and collagenesis-inducing action in vitro. These findings provide solid grounds for us to advance IL-KTTKS conjugates as promising leads for future development of topical treatments for complicated skin and soft tissue infections (cSSTI). Further studies are envisaged to incorporate IL-conjugates into suitable nanoformulations, to reduce toxicity and/or improve resistance to proteolytic degradation.
- Dental implant surface decontamination and surface change of an electrolytic method versus mechanical approaches : a pilot in vitro studyPublication . Assunção, Mariana Anselmo; Botelho, João; Machado, Vanessa; Proença, Luís; Matos, António P. A.; Mendes, José João; Bessa, Lucinda J.; Taveira, Nuno; Santos, AlexandreDental implants are the preferred fixed oral rehabilitation for replacing lost teeth. When peri-implant tissues become inflamed, the removal of plaque accumulating around the implant becomes imperative. Recently, several new strategies have been developed for this purpose, with electrolytic decontamination showing increased potential compared to traditional mechanical strategies. In this in vitro pilot study, we compare the efficacy of an electrolytic decontaminant (Galvosurge®) with an erythritol jet system (PerioFlow®) and two titanium brushes (R-Brush™ and i-Brush™) in removing Pseudomonas aeruginosa PAO1 biofilms from implants. Changes in the implant surface after each approach were also evaluated. Twenty titanium SLA implants were inoculated with P. aeruginosa and then randomly assigned to each treatment group. After treatment, decontamination efficacy was assessed by quantifying colony-forming units (log10 CFU/cm2) from each implant surface. Scanning electron microscopy was used to analyse changes in the implant surface. With the exception of R-Brush, all treatment strategies were similarly effective in removing P. aeruginosa from implants. Major surface changes were observed only in implants treated with titanium brushes. In conclusion, this pilot study suggests that electrolytic decontamination, erythritol-chlorhexidine particle jet system and i-Brush™ brushing have similar performance in removing P. aeruginosa biofilm from dental implants. Further studies are needed to evaluate the removal of more complex biofilms. Titanium brushes caused significant changes to the implant surface, the effects of which need to be evaluated.
- Disclosure of a promising lead to tackle complicated skin and skin structure infections : antimicrobial and antibiofilm actions of peptide PP4-3.1Publication . Gomes, Ana; Bessa, Lucinda J.; Fernandes, Iva; Ferraz, Ricardo; Monteiro, Cláudia; Martins, M. Cristina L.; Mateus, Nuno; Gameiro, Paula; Teixeira, Cátia; Gomes, PaulaEfficient antibiotics are being exhausted, which compromises the treatment of infections, including complicated skin and skin structure infections (cSSTI) often associated with multidrug resistant (MDR) bacteria, methicillin-resistant S. aureus (MRSA) being the most prevalent. Antimicrobial peptides (AMP) are being increasingly regarded as the new hope for the post-antibiotic era. Thus, future management of cSSTI may include use of peptides that, on the one hand, behave as AMP and, on the other, are able to promote fast and correct skin rebuilding. As such, we combined the well-known cosmeceutical pentapeptide-4 (PP4), devoid of antimicrobial action but possessing collagenesis-boosting properties, with the AMP 3.1, to afford the chimeric peptide PP4-3.1. We further produced its N-methyl imidazole derivative, MeIm-PP4-3.1. Both peptide-based constructs were evaluated in vitro against Gram-negative bacteria, Gram-positive bacteria, and Candida spp. fungi. Additionally, the antibiofilm activity, the toxicity to human keratinocytes, and the activity against S. aureus in simulated wound fluid (SWF) were assessed. The chimeric peptide PP4-3.1 stood out for its potent activity against Gram-positive and Gram-negative bacteria, including against MDR clinical isolates (0.8 ≤ MIC ≤ 5.7 µM), both in planktonic form and in biofilm matrix. The peptide was also active against three clinically relevant species of Candida fungi, with an overall performance superior to that of fluconazole. Altogether, data reveal that PP4-3.1 is as a promising lead for the future development of new topical treatments for severe skin infections.
- Editorial : coping with antimicrobial resistance in the context of dental medicinePublication . Bessa, Lucinda J.; D’Ercole, Simonetta; Alves, RicardoEditorial
- Editorial : insights in antimicrobials, resistance & chemotherapy : 2022Publication . Bessa, Lucinda J.; Shaaban, Mona; Aminov, Rustam
- Editorial : the immune microenvironment-microbiome interactions in peri-implantitis and periodontitisPublication . Bessa, Lucinda J.; An, Ying; Li, ZejianEditorial
- Enhanced efficacy of laser-activated irrigation (Er,Cr:YSGG) in eradicating Enterococcus faecalis biofilm in 3D-printed molar replicas : a pilot studyPublication . Macedo, Margarida; Neves, João Albernaz; Pérez, Alejandro R.; Proença, Luís; Bessa, Lucinda J.Objectives: This study compared the efficacy of Sonic (EDDY) and Er,Cr:YSGG (2780 nm) laser activation in eradicating Enterococcus faecalis biofilm formed in 3D-printed molar replicas with two mesial canals and one distal canal. Materials and Methods: An in vitro design was implemented using 20 3D-printed mandibular molar replicas mimicking the natural canal morphology. Root canals were inoculated with E. faecalis and incubated for 21 days to allow the development of a mature biofilm. Three irrigation protocols were tested: Conventional needle irrigation (CNI), EDDY sonic activation (SA), and Er,Cr:YSGG (2780 nm) laser activation (LA). The control group was irrigated with phosphate-buffered saline (PBS) without activation. Residual bacterial load was quantified through colony-forming unit (CFU) counts and quantitative PCR (qPCR). Bacterial viability in the apical isthmus was assessed using fluorescence microscopy. A Student's t-test was performed to identify significant differences between CFU/mL values in groups, with significance set at 5% (p < 0.05). Results: CFU counts of E. faecalis were significantly lower in the CNI, SA, and LA groups compared to the control (p < 0.05). In the SA and LA groups, bacterial counts were reduced to the lower detection limit (< log10 CFU/mL of 1.00), suggesting near-total bacterial elimination. qPCR and fluorescence microscopy corroborated these results, providing greater differentiation between the outcomes of sonic and laser activations. Conclusions: Er,Cr:YSGG (2780 nm) laser activation showed superior efficacy in endodontic disinfection by effectively eradicating E. faecalis biofilm, including in the challenging isthmus region, representing a promising method for complex root canal anatomies.
- Exploring AI-driven machine learning approaches for optimal classification of peri-implantitis based on oral microbiome data : a feasibility studyPublication . Pais, Ricardo Jorge; Botelho, João; Machado, Vanessa; Alcoforado, Gil; Mendes, José João; Alves, Ricardo; Bessa, Lucinda J.Background: Machine learning (ML) techniques have been recently proposed as a solution for aiding in the prevention and diagnosis of microbiome-related diseases. Here, we applied auto-ML approaches on real-case metagenomic datasets from saliva and subgingival peri-implant biofilm microbiomes to explore a wide range of ML algorithms to benchmark best-performing algorithms for predicting peri-implantitis (PI). Methods: A total of 100 metagenomes from the NCBI SRA database (PRJNA1163384) were used in this study to construct biofilm and saliva metagenomes datasets. Two AI-driven auto-ML approaches were used on constructed datasets to generate 100 ML-based models for the prediction of PI. These were compared with statistically significant single-microorganism-based models. Results: Several ML algorithms were pinpointed as suitable bespoke predictive approaches to apply to metagenomic data, outperforming the single-microorganism-based classification. Auto-ML approaches rendered high-performing models with Receiver Operating Characteristic–Area Under the Curve, sensitivities and specificities between 80% and 100%. Among these, classifiers based on ML-driven scoring of combinations of 2–4 microorganisms presented top-ranked performances and can be suitable for clinical application. Moreover, models generated based on the saliva microbiome showed higher predictive performance than those from the biofilm microbiome. Conclusions: This feasibility study bridges complex AI research with practical dental applications by benchmarking ML algorithms and exploring oral microbiomes as foundations for developing intuitive, cost-effective, and clinically relevant diagnostic platforms.
- Linking peri-implantitis to microbiome changes in affected implants, healthy implants, and saliva : a cross-sectional pilot studyPublication . Bessa, Lucinda J.; Egas, Conceição; Pires, Carolina; Proença, Luís; Mascarenhas, Paulo; Pais, Ricardo J.; Barroso, Helena; Machado, Vanessa; Botelho, João; Alcoforado, Gil; Mendes, José João; Alves, RicardoIntroduction: The rising use of dental implants is accompanied by an expected increase in peri-implant diseases, particularly peri-implantitis (PI), which poses a significant threat to implant success and necessitates a thorough understanding of its pathogenesis for effective management. Methods: To gain deeper insights into the role and impact of the peri-implant microbiome in the pathogenesis and progression of PI, we analyzed 100 samples of saliva and subgingival biofilm from 40 participants with healthy implants (HI group) or with co-occurrence of diagnosed PI-affected implants and healthy implants (PI group) using shotgun metagenomic sequencing. We identified the most discriminative species distinguishing healthy from diseased study groups through log ratios and differential ranking analyses. Results and discussion: Mogibacterium timidum, Schaalia cardiffensis, Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis, Porphyromonas gingivalis and Olsenella uli were associated with the subgingival peri-implant biofilm. In contrast, Neisseria sp oral taxon 014, Haemophilus parainfluenzae, Actinomyces naeslundii, Rothia mucilaginosa and Rothia aeria were more prevalent in the healthy peri-implant biofilm. Functional pathways such as arginine and polyamine biosynthesis, including putrescine and citrulline biosynthesis, showed stronger correlations with PI-affected implants. In contrast, peri-implant health was characterized by the predominance of pathways involved in purine and pyrimidine deoxyribonucleotide de novo biosynthesis, glucose and glucose-1-phosphate degradation, and tetrapyrrole biosynthesis. Our findings reveal that healthy implants in PI-free oral cavities differ significantly in microbial composition and functional pathways compared to healthy implants co-occurring with PI-affected implants, which more closely resemble PI-associated profiles. This pattern extended to salivary samples, where microbial and functional biomarkers follow similar trends.
- Managing oral health in the context of antimicrobial resistancePublication . Bessa, Lucinda J.; Botelho, João; Machado, Vanessa; Alves, Ricardo; Mendes, José JoãoThe oral microbiome plays a major role in shaping oral health/disease state; thus, a main challenge for dental practitioners is to preserve or restore a balanced oral microbiome. Nonetheless, when pathogenic microorganisms install in the oral cavity and are incorporated into the oral biofilm, oral infections, such as gingivitis, dental caries, periodontitis, and peri-implantitis, can arise. Several prophylactic and treatment approaches are available nowadays, but most of them have been antibiotic-based. Given the actual context of antimicrobial resistance (AMR), antibiotic stewardship in dentistry would be a beneficial approach to optimize and avoid inappropriate or even unnecessary antibiotic use, representing a step towards precision medicine. Furthermore, the development of new effective treatment options to replace the need for antibiotics is being pursued, including the application of photodynamic therapy and the use of probiotics. In this review, we highlight the advances undergoing towards a better understanding of the oral microbiome and oral resistome. We also provide an updated overview of how dentists are adapting to better manage the treatment of oral infections given the problem of AMR.