Benedita Sampaio-Maia | Faculdade de Medicina Dentária da Universidade do Porto (original) (raw)

Papers by Benedita Sampaio-Maia

Advances in Applied Microbiology, 2016

The oral microbiome can alter the balance between health and disease, locally and systemically. W... more The oral microbiome can alter the balance between health and disease, locally and systemically. Within the oral cavity, bacteria, archaea, fungi, protozoa, and viruses may all be found, each having a particular role, but strongly interacting with each other and with the host, in sickness or in health. A description on how colonization occurs and how the oral microbiome dynamically evolves throughout the host's life is given. In this chapter the authors also address oral and nonoral conditions in which oral microorganisms may play a role in the etiology and progression, presenting the up-to-date knowledge on oral dysbiosis as well as the known underlying pathophysiologic mechanisms involving oral microorganisms in each condition. In oral pathology, oral microorganisms are associated with several diseases, namely dental caries, periodontal diseases, endodontic infections, and also oral cancer. In systemic diseases, nonoral infections, adverse pregnancy outcomes, cardiovascular diseases, and diabetes are among the most prevalent pathologies linked with oral cavity microorganisms. The knowledge on how colonization occurs, how oral microbiome coevolves with the host, and how oral microorganisms interact with each other may be a key factor to understand diseases etiology and progression.

Applied Microbiology and Biotechnology

The phylum Pseudomonadota is amongst the most represented in the environment, with a comparativel... more The phylum Pseudomonadota is amongst the most represented in the environment, with a comparatively lower prevalence in the human oral cavity. The ubiquity of Pseudomonadota and the fact that the oral cavity is the most likely entry portal of bacteria from external sources underlie the need to better understand its occurrence in the interface environment-humans. Yet, the relevance oral Pseudomonadota is largely underexplored in the scientific literature, a gap that this review aims at addressing by making, for the first time, an overview of the diversity and ecology of Pseudomonadota in the oral cavity. The screening of scientific literature and human microbiome databases unveiled 1328 reports of Pseudomonadota in the oral cavity. Most of these belonged to the classes Beta- and Gammaproteobacteria, mainly to the families Neisseriaceae, Campylobacteriaceae, and Pasteurelaceae. Others also regularly reported include genera such as Enterobacter, Klebsiella, Acinetobacter, Escherichia, B...

Medicina Oral Patología Oral y Cirugia Bucal, 2017

Background: Recent studies suggest that placenta may harbour a unique microbiome that may have or... more Background: Recent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with non-pregnant women. Material and Methods: The oral yeast colonization was assessed in saliva of 30 pregnant and non-pregnant women longitudinally over a 6-months period. Demographic information was collected, a non-invasive intra-oral examination was performed and saliva flow and pH were determined. Results: Pregnant and non-pregnant groups were similar regarding age and level of education. Saliva flow rate did not differ, but saliva pH was lower in pregnant than in non-pregnant women. Oral yeast prevalence was higher in pregnant than in non-pregnant women, either in the first or in the third trimester, but did not attain statistical significance. In individuals colonized with yeast, the total yeast quantification (Log 10 CFU/mL) increase from the 1 st to the 3 rd trimester in pregnant women, but not in non-pregnant women. Conclusions: Pregnancy may favour oral yeast growth that may be associated with an acidic oral environment.

Microorganisms, 2020

Factors influencing the occurrence of peritoneal dialysis (PD)-related infections are still far f... more Factors influencing the occurrence of peritoneal dialysis (PD)-related infections are still far from fully understood. Recent studies described the existence of specific microbiomes in body sites previously considered microbiome-free, unravelling new microbial pathways in the human body. In the present study, we analyzed the peritoneum of end-stage kidney disease (ESKD) patients to determine if they harbored a specific microbiome and if it is altered in patients on PD therapy. We conducted a cross-sectional study where the peritoneal microbiomes from ESKD patients with intact peritoneal cavities (ESKD non-PD, n = 11) and ESKD patients undergoing PD therapy (ESKD PD, n = 9) were analyzed with a 16S rRNA approach. Peritoneal tissue of ESKD patients contained characteristically low-abundance microbiomes dominated by Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Patients undergoing PD therapy presented lower species richness, with dominance by the Pseudomonadaceae and P...

Frontiers in Microbiology, 2021

Chronic Kidney Disease (CKD) is a growing public-health concern worldwide. Patients exhibit compr... more Chronic Kidney Disease (CKD) is a growing public-health concern worldwide. Patients exhibit compromised immunity and are more prone to infection than other populations. Therefore, oral colonization by clinically relevant members of the Enterobacteriaceae family, major agents of both nosocomial and dialysis-associated infections with frequent prevalence of antibiotic resistances, may constitute a serious risk. Thus, this study aimed to assess the occurrence of clinically relevant enterobacteria and their antibiotic resistance profiles in the oral cavity of CKD patients undergoing peritoneal dialysis (CKD-PD) and compare it to healthy controls. Saliva samples from all the participants were cultured on MacConkey Agar and evaluated regarding the levels of urea, ammonia, and pH. Bacterial isolates were identified and characterized for antibiotic resistance phenotype and genotype. The results showed that CKD-PD patients exhibited significantly higher salivary pH, urea, and ammonia levels ...

International Urology and Nephrology, 2021

Purpose It has been proved that the gut microbiome is altered in patients with chronic kidney dis... more Purpose It has been proved that the gut microbiome is altered in patients with chronic kidney disease. This contributes to chronic inflammation and increases cardiovascular risk and mortality, especially in those undergoing hemodialysis. Phosphate binders may potentially induce changes in their microbiome. This trial aimed to compare the changes in the gut microbiome of hemodialysis patients treated with calcium acetate to those treated with sucroferric oxyhydroxide. Methods Twelve hemodialysis patients were distributed to receive calcium acetate or sucroferric oxyhydroxide for 5 months. Blood samples (for biochemical analysis) and stool samples (for microbiome analysis) were collected at baseline, 4, 12, and 20 weeks after treatment initiation. Fecal DNA was extracted and a 16S rRNA sequencing library was constructed targeting the V3 and V4 hypervariable regions. Results Regarding clinical variables and laboratory parameters, no statistically significant differences were observed b...

Medical Express, 2017

BACKGROUND: Patients with mucopolysaccharidosis have several changes of the stomatognathic comple... more BACKGROUND: Patients with mucopolysaccharidosis have several changes of the stomatognathic complex, representing a challenge for dentists. OBJECTIVE: The study aimed to evaluate and characterize oral health in patients with mucopolysaccharidosis in a reference center of Portugal. METHOD: The sample consisted of twelve participants with mucopolysaccharidosis followed in Metabolic Diseases Unit of the S. João Hospital Centre and twelve healthy participants followed at Faculty of Dental Medicine, University of Porto. The clinical oral evaluation was performed by a complete extra-oral and intra-oral examination to assess the presence of oral pathologies, gingival index and occlusion status. RESULTS: Mucoplysaccaridosis patients and controls presented similar age ranges and sex distribution. In comparison to controls, children with mucopolysaccharidosis presented a higher prevalence of tooth decay, gingival bleeding, macroglossia, dental hypoplasia, lingual interposition, delayed tooth eruption, anterior open bite, right and left posterior cross-bite, limitation of mouth opening, alteration on the size and shape of the teeth, diastemata and maxillary compression. CONCLUSIONS: Patients with mucopolysaccharidosis have a high prevalence eruption delay, teeth morphology alterations, occlusal problems, dental caries and bleeding gums, highlighting the need of oral health care providers to improve diagnostics and preventive protocols to overcome the factors that limit the oral health of these patients and promote together with parent/caregiver efficient oral care strategies.

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Oral health & preventive dentistry, 2020

PURPOSE To investigate if pregnancy represents a period of increased risk of non-cavitated dental... more PURPOSE To investigate if pregnancy represents a period of increased risk of non-cavitated dental caries related to changes in saliva and oral health behaviours. MATERIALS AND METHODS A non-randomised longitudinal study was performed with 27 pregnant women and 25 non-pregnant women, who were evaluated twice with the same time gap (24 weeks on average). At the first visit sociodemographic and oral health-related behaviours were assessed through a structured questionnaire. At the second visit changes related to eating sweet snacks and oral hygiene habits were also assessed. In both visits the surface-related caries status was evaluated according to ICDAS II criteria. Calculation of D0 (Sound), D1-2 (visual changes) and D3-4 (precavitated caries lesions) Index was based on data collected from clinical examination. Saliva pH and saliva flow rate were also assessed. RESULTS Throughout pregnancy, a statistically significant increase of eating sweet snacks between main meals was reported, ...

Introduction and Aims: Haemodialysis (HD) patients who develop myocardial dysfunction have a poor... more Introduction and Aims: Haemodialysis (HD) patients who develop myocardial dysfunction have a poor prognosis. Recurrent sub clinical myocardial ischaemia is an important risk factor in the development of heart failure in non dialysis patients. We have previously demonstrated that sub clinical myocardial ischaemia develops during HD. HD patients prone to episodes of intradialytic hypotension (IDH) have higher levels of circulating cardiac troponin T (cTnT) than non IDH-prone dialysis patients. HD patients with an elevated cTnT also have an increased incidence of mortality from all causes. We sought to examine whether increased cTnT levels were associated with the development, frequency and severity of left ventricular (LV) regional wall motion abnormalities (RWMAs). Methods: We studied 38 prevalent HD patients and took blood samples for cTnT immediately prior to (baseline), immediately after the end of (post) and 48hours after HD treatment. At the same treatment session, serial echocardiography with quantitative analysis was performed pre-dialysis, at peak stress and during recovery. This was used to assess the development of wall motion abnormalities over 10 regions of the left ventricle. A motion abnormality was defined as a reduction in movement of >20% from baseline and >2 RWMAs were significant. Severity was scored as a composite of the number of RWMA and the magnitude of reduction in motion. Results: Circulating plasma cTnT levels did not correlate with left ventricular mass index (LVMI) (P=0.37). Increased LVMI was not associated with the development of RWMAs (P=0.25). Patients who developed RW-MAs during HD had a higher baseline cTnT (0.028±0.006 vs. 0.1±0.017, P=0.017). However, there was no correlation between levels of cTnT and the severity of stunning as evidenced by numbers of RWMAs (P=0.3) or the magnitude of reduction (P=0.31). There was also no significant rise in the post (P=0.49) and 48 hour (P=0.48) cTnT levels from baseline in those patients who developed left ventricular RWMAs. Conclusions: The development of left ventricular RWMAs is associated with an elevated cTnT. However, plasma cTnT levels do not forecast the number of RWMAs that develop or their severity. Circulating biomarkers of myocardial injury may be of use to identify patients experiencing dialysis induced myocardial stunning. However, the degree of elevation appears to correlate poorly with the severity of the functional insult.

In the periphery, physiological dopamine increases renal blood flow, decreases renal resistance a... more In the periphery, physiological dopamine increases renal blood flow, decreases renal resistance and acts on the kidney tubule to enhance natriuresis and diuresis. Dopamine receptors can be divided into D 1 -like (D 1 and D 5 ) receptors that stimulate adenylyl cyclase and D 2 -like (D 2 , D 3 and D 4 ) receptors that inhibit adenylyl cyclase. Both the D 1 -like and D 2 -like receptors are expressed in the kidney. Dopamine is synthesized in the epithelial cells of the proximal tubules which are endowed with a high aromatic L-amino acid decarboxylase (L-AADC)

The Journal of forensic odonto-stomatology, 2020

Lip print patterns are referred to as unique to each individual, but controversy exists surroundi... more Lip print patterns are referred to as unique to each individual, but controversy exists surrounding twins. In this study, the lip prints of 19 pairs of monozygotic and 47 pairs of dizygotic twins were studied. The left lower lip was photographed and the furrows were classified using Renaud's classification. Results showed the same lip pattern was found only in one monozygotic pair (5.3%) and in 4 dizygotic pairs (8.5%), and no significant statistical differences were found between groups (p > 0.05). In monozygotic twins only type C furrows presence displayed statistical significant differences (p=0.034). As for dizygotic twins, there were statistical significant differences in the frequency of type A (p=0.005) and type G furrows (p=0.018). As for the most common types, both groups displayed a higher prevalence of vertical furrows (type B: 97.4% and 96.8%, type A: 86.8% and 87.2%, in monozygotic and dizygotic, respectively). The least frequent furrow type was type I and type E...

Bioanalysis, 2020

Aim: Salivary urea and ammonium levels are potential biomarkers for chronic kidney disease. A fas... more Aim: Salivary urea and ammonium levels are potential biomarkers for chronic kidney disease. A fast and efficient assessment of these compounds in the saliva of healthy and diseased individuals may be a useful tool to monitor kidney function. Materials & methods: Ammonium ions were measured with an ammonia selective electrode after conversion to ammonia gas. A urease reactor was incorporated in the manifold to hydrolyze urea to ammonium, thereby providing values of ammonia from both urea and ammonium ions in the sample. The accuracy of the method was assessed by comparison with a commercially available kit for urea and ammonium determination. Conclusion: A sequential injection method for the biparametric determination of salivary urea and ammonium employing a single sequential injection manifold was successfully applied to samples collected from both healthy volunteers and chronic kidney disease patients.

International Journal of Pharmaceutics, 2020

The progressive loss of renal function in chronic kidney disease (CKD) leads to the accumulation ... more The progressive loss of renal function in chronic kidney disease (CKD) leads to the accumulation of uremic toxins. Recent studies related uremic plasma as well dysbiotic gut microbiome to impaired intestinal barrier function, allowing the translocation of microorganisms or by-products from the intestinal lumen to systemic circulation, contributing to systemic inflammation, cardiovascular risk and progression of CKD. Our main goal was to evaluate the impact of different uremic conditions on an improved in vitro intestinal Caco-2/HT29-MTX/ Raji B triple co-culture model. For that, the impact of CKD patients' plasma and elevated urea concentration and its by-products on the triple model was assessed. The results showed that uremic conditions did not potentiate the Escherichia coli (E. coli) translocation, although may interfere with the integrity and the permeability of the intestinal barrier. Also, results showed that E. coli translocation was higher in Caco-2 monoculture than in Caco-2/HT29-MTX/Raji B triple model, suggesting that the triple model creates a more effective intestinal barrier. This study allowed to conclude that the uremic state influences the integrity of the intestinal barrier, but this influence could not be directly translated in an increase on the E. coli translocation through the intestinal epithelium, at least in Caco-2/HT29-MTX/Raji B intestinal epithelial barrier model.

Canadian Journal of Infectious Diseases and Medical Microbiology, 2018

Peritoneal dialysis-related infections are important morbidity/mortality causes, being staphyloco... more Peritoneal dialysis-related infections are important morbidity/mortality causes, being staphylococci the most prevalent agents. SinceStaphylococcus aureusnasopharynx carriage is a known risk factor for PD infections and the oral cavity is a starting point for systemic diseases development, we aimed at comparing the oral staphylococci colonization between PD patients and controls and studying the association with PD-related infections. Saliva samples were plated in Mannitol salt, and isolates were identified byDnaJgene sequencing. Staphylococci PD-related infections were recorded throughout the 4-year period following sample collection.Staphylococcuscolonization was present in >90% of the samples from both groups (a total of nine species identified). PD patients presented less diversity and less prevalence of multispeciesStaphylococcuscolonization. Although all patients presentingStaphylococcus epidermidisPD-related infections were also colonized in the oral cavity by the same age...

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Mycopathologia, Jan 6, 2018

Aspergillus fumigatus is the species section Fumigati most frequently isolated from the respirato... more Aspergillus fumigatus is the species section Fumigati most frequently isolated from the respiratory tract of cystic fibrosis (CF) patients. Recent studies suggest that mutations in the Cyp51 gene, particularly TR/L98H, are responsible for azole resistance. The focus of this study was on section Fumigati isolates isolated from the respiratory tract samples of CF patients. More specifically, the goal was to detect A. fumigatus isolates, test their antifungal susceptibility to itraconazole, voriconazole and posaconazole, and finally determine the presence of TR/L98H and other mutations in the isolates Cyp51A gene. A set of 31 isolates of Aspergillus section Fumigati were obtained from the sputum samples of 6 CF patients and subsequently identified to species level by microsatellite genotyping. All isolates were determined as A. fumigatus and involved 14 different genotypes. The minimal inhibitory concentrations to the three azoles were determined by the E-test method, and the Cyp51A ge...

Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, Jan 23, 2018

Autopsies, including minimally-invasive autopsies, are a powerful tool for determination of the c... more Autopsies, including minimally-invasive autopsies, are a powerful tool for determination of the cause of death. When a patient dies from an infection, microbiology is crucial to identify the causative organism. Post-mortem microbiology (PMM) aims to: detect unexpected infections causing sudden deaths; confirm clinically suspected but unproven infection; evaluate the efficacy of antimicrobial therapy; identify emergent pathogens; and recognize medical errors. Additionally, the analysis of the thanatomicrobiome may help to estimate the post-mortem interval. To provide advice in the collection of PMM samples and to propose sampling guidelines for microbiologists advising autopsy pathologists facing different sudden death scenarios. A multidisciplinary team with experts in various fields of microbiology and autopsies on behalf of the ESGFOR (ESCMID - European Society of Clinical Microbiology and Infectious Diseases - study group of forensic and post-mortem microbiology and in collaborat...

BioMed research international, 2018

Puromycin aminonucleoside-induced nephrotic syndrome (PAN-NS) is characterized by cardiac remodel... more Puromycin aminonucleoside-induced nephrotic syndrome (PAN-NS) is characterized by cardiac remodeling and increased local inflammatory activity. Patients with NS and animal models of NS have vitamin D3 deficiency. The aim of the present study was to evaluate the influence of calcitriol on cardiac remodeling and local inflammatory state in PAN-NS rat model. Male Sprague-Dawley rats were injected with PAN or vehicle on day 0. PAN and control rats were divided into two subgroups for the administration of calcitriol (PAN-D and Ct-D groups) or the vehicle (PAN-V and Ct-V groups) during 21 days. On day 21, the renal function, metabolic balance, calcitriol and FGF-23 plasma levels, prohypertrophy and proinflammatory markers (ET-1, TGF-1, TNF-, and IL-1), and calcium signaling molecules (PLB and SERCA-2a) were evaluated. Twenty-one days after injection, PAN-V group presented cardiac hypertrophy and a modulation of proinflammatory markers local expression. Calcitriol treatment of PAN rats pre...

Advances in applied microbiology, 2018

The availability of complete fungal genomes is expanding rapidly and is offering an extensive and... more The availability of complete fungal genomes is expanding rapidly and is offering an extensive and accurate view of this "kingdom." The scientific milestone of free access to more than 1000 fungal genomes of different species was reached, and new and stimulating projects have meanwhile been released. The "1000 Fungal Genomes Project" represents one of the largest sequencing initiative regarding fungal organisms trying to fill some gaps on fungal genomics. Presently, there are 329 fungal families with at least one representative genome sequenced, but there is still a large number of fungal families without a single sequenced genome. In addition, additional sequencing projects helped to understand the genetic diversity within some fungal species. The availability of multiple genomes per species allows to support taxonomic organization, brings new insights for fungal evolution in short-time scales, clarifies geographical and dispersion patterns, elucidates outbreaks ...

Pharmacological research, Jan 11, 2018

Chronic kidney disease (CKD) is associated with an imbalanced human microbiome due not only to CK... more Chronic kidney disease (CKD) is associated with an imbalanced human microbiome due not only to CKD-associated factors such as uremia, increased inflammation and immunosuppression, but also to pharmacological therapies and dietary restrictions. End-stage renal disease patients require renal replacement therapies commonly in the form of hemodialysis (HD) or peritoneal dialysis (PD). HD implies the existence of a vascular access, such as an arteriovenous fistula/graft or a venous catheter, whereas PD implies a long-term peritoneal catheter and the constant inflow of peritoneal dialysate. Also, dietary adaptations are mandatory in both therapies. This revision explores the impact of HD or PD therapies on human microbiome. HD and PD appear to be associated with different changes in the gut microbiome, for example a decrease in Proteobacteria relative abundance in HD patients and increase in PD patients. Both therapies may also have an impact on the human microbiome beyond the gut, leadin...