Browsing by Author "Sampaio-Maia, Benedita"
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- Potential pathogenic and opportunistic oral bacteria in early life: the role of maternal factors in a portuguese populationPublication . Fernandes, Mariana; Azevedo, Maria João; Campos, Carla; Ferreira, Ana Filipa; Azevedo, Álvaro; Falcão-Pires, Inês; Zaura, Egija; Ramalho, Carla; Campos, Joana; Sampaio-Maia, BeneditaIn early life, maternal factors are of the utmost relevance for oral microbiome acquisition and maturation. Therefore, our study explored the impact of maternal factors, such as saliva and breastmilk colonization, cardiovascular risk factors (CRF), type of delivery, oral health, and caregiving habits on the prevalence of potential pathogenic and opportunistic oral bacteria in early life. A total of 26 healthy mothers, 23 mothers with CRF, and their 50 children were included and samples (child’s oral swabs, mother’s saliva, and breastmilk) were collected 4 to 12 weeks after delivery and inoculated in selective and differential media for detection of non-fastidious Gram-negative and Gram-positive bacteria to isolate potential pathogenic and opportunistic bacteria identified by MALDI-TOF MS (414 isolates). Within mother–child dyads, the same species were identified in 86% of the pairs and potential pathogenic microorganisms from the Staphylococcaceae and Enterobacteriaceae families were found to be statistically significantly concordant between mother–child samples, particularly in the healthy group. Staphylococcus saprophyticus and Stenotrophomonas maltophilia oral colonization in mother–child pairs were associated with the presence of CRF. Breastfeeding was related to the early life oral colonization of Staphylococcus epidermidis in children from healthy mothers and C-section was associated with higher diversity of pathogens, independent of cardiovascular status (p = 0.05). This study reveals the presence of potential oral opportunistic and pathogenic bacteria in early life and highlights the importance of maternal factors in its acquisition.
- Sample preparation and chromatographic methods for the determination of protein-bound uremic retention solutes in human biological samples: An overviewPublication . Fernandes, Sara R.; Meireles, Andreia N.; Marques, Sara S.; Silva, Luís; Barreiros, Luisa; Sampaio-Maia, Benedita; Miro, Manuel; Segundo, Marcela A.Protein-bound uremic retention solutes, such as indole-3-acetic acid, indoxyl sulfate, p-cresol and p-cresol sulfate, are associated with the development of several pathologies, namely renal, cardiovascular, and bone toxicities, due to their potential accumulation in the human body, thus requiring analytical methods for monitoring and evaluation. The present review addresses conventional and advanced sample treatment procedures for sample handling and the chromatographic analytical methods developed for quantification of these compounds in different biological fluids, with particular focus on plasma, serum, and urine. The sample preparation and chromatographic methods coupled to different detection systems are critically discussed, focusing on the different steps involved for sample treatment, namely elimination of interfering compounds present in the sample matrix, and the evaluation of their environmental impact through the AGREEprep tool. There is a clear trend for the application of liquid-chromatography coupled to tandem mass spectrometry, which requires protein precipitation, solid-phase extraction and/or dilution prior to analysis of biological samples. Furthermore, from a sustainability point of view, miniaturized methods resorting to microplate devices are highly recommended.
- Total analysis system for the determination of uremic toxins in human plasma based on bead injection solid phase extraction hyphenated to mass spectrometryPublication . Fernandes, Sara; Barreiros, Luísa; Sampaio-Maia, Benedita; Miró, Manuel; Segundo, Marcela A.Indoxyl sulfate (INDS) and p-cresol sulfate (pCS) are two of the most relevant uremic toxins that are recognized to have an essential role in chronic kidney disease (CKD) progression and associated cardiovascular risk. Thus, it is crucial to accurately assess their circulating levels in the body. Aiming at establishing an analytical strategy for quantification of INDS and pCS in human plasma, an automatic on-line micro-solid-phase extraction (μSPE) procedure hyphenated to tandem mass spectrometry (MS/MS) detection without previous chromatographic separation was herein developed. The bead injection (BI) concept was used to implement the μSPE procedure in the lab-on-valve (LOV) format. After studying the extraction conditions, the anion-exchange OASIS WAX sorbent beads (10 mg) and 99% ACN–H2O (15:85, v/v)–1% (v/v) NH4OH were chosen as sorbent and eluent, respectively, as they provided the highest analyte recoveries. Subsequently, the μSPE-BI-LOV system was hyphenated on-line to a MS/MS detector and the full analytical cycle, comprising sample preparation and analytes detection, was completed in <20 min. The developed μSPE-BI-LOV-MS methodology presented good linearity (r2 > 0.999) for quantification of the target analytes at concentrations ranging from 18 to 360 μg mL−1 in plasma. LOQ values were 2 μg mL−1 for INDS and 7 μg mL−1 for pCS in plasma. Human plasma samples from healthy subjects and individuals with CKD were successfully analyzed using the developed approach. The proposed automatic methodology can be described as an eco-friendly strategy, with a favorable score of 0.64 after greenness evaluation using the AGREE metric.
- Unveiling the relevance of the oral cavity as a staphylococcus aureus colonization site and potential source of antimicrobial resistancePublication . Campos, Joana; Faria Pires, Mariana; Sousa, Marta; Campos, Carla; Fernandes Ferreira Alves da Costa, Carolina; Sampaio-Maia, BeneditaStaphylococcus aureus is both a human commensal and a pathogen, that causes serious nosocomial and community-acquired infections. Despite nostrils being considered its preferred host habitat, the oral cavity has been demonstrated to be an ideal starting point for auto-infection and transmission. The antibiotic resistance assessment of S. aureus is a priority and is often reported in clinical settings. This study aimed to explore the prevalence and antimicrobial susceptibility of S. aureus in the oral and nasal cavities of healthy individuals. The participants (n = 101) were subjected to a demographic and clinical background survey, a caries evaluation, and to oral and nasal swabbing. Swabs were cultured in differential/selective media and S. aureus isolates were identified (MALDI-TOF MS) and tested for antibiotic susceptibility (EUCAST/CLSI). Similar S. aureus prevalence was found exclusively on nasal (13.9%) or oral (12.0%) habitats, whereas 9.9% of the population were simultaneous nasal and oral carriers. In oro-nasal cavities, similar antibiotic resistance rates (83.3–81.5%), including MDR (20.8–29.6%), were observed. Notably, 60% (6/10) of the simultaneous nasal and oral carriers exhibited different antibiotic resistance profiles between cavities. This study demonstrates the relevance of the oral cavity as an independent colonization site for S. aureus and as a potential source of antimicrobial resistance, a role which has been widely neglected so far.
- Vertical transmission and antifungal susceptibility profile of yeast isolates from the oral cavity, gut, and breastmilk of mother–child pairs in early lifePublication . Azevedo, Maria João; Araújo, Ricardo; Campos, Joana; Campos, Carla; Ferreira, Ana Filipa; Falcão-Pires, Inês; Ramalho, Carla; Zaura, Egija; Pinto, Eugénia; Sampaio-Maia, BeneditaYeast acquisition begins at birth; however, the contribution of the mother on yeast trans mission to the offspring and associated resistance is yet to be clarified. The aim of this study was to explore the vertical transmission of yeasts and their antifungal susceptibility profile in early life. Oral, fecal, and breastmilk samples were collected from 73 mother–child pairs four to twelve weeks after delivery and cultured on Sabouraud dextrose agar with chloramphenicol. The isolates were identified by MALDI-TOF MS. The vertical transmission was studied by microsatellite genotyping. Antifungal susceptibility was determined for fluconazole, voriconazole, miconazole, anidulafungin, and nystatin by broth microdilution assay, following CLSI–M60 guidelines. A total of 129 isolates were identified from 53% mother–child pairs. We verified the vertical transmission of Candida albicans (n = three mother–child pairs) and Candida parapsilosis (n = one mother–child pair) strains, includ ing an antifungal resistant strain transmitted from breastmilk to the gut of a child. Most isolates were susceptible to the tested antifungals, with the exception of four C. albicans isolates and one R. mucilaginosa isolate. The vertical transmission of yeasts happens in early life. This is the first work that demonstrated the role of the mother as a source of transmission of antifungal-resistant yeasts to the child.