Diversity of pneumococcal surface protein A (PspA) among prevalent clones in Spain

<p>Abstract</p> <p>Background</p> <p>PspA is recognized as a major pneumococcal virulence factor and a possible vaccine candidate. The aim of this study was to analyze the PspA family and clade distribution among 112 Spanish pneumococci representatives of dominant clones among patients with invasive disease (n = 66) and nasopharyngeal healthy carriage in children (n = 46).</p> <p>Results</p> <p>PspA family 2 was predominant among invasive (63.6%) and carriage (54.3%) pneumococcal isolates. No PspA family 3 isolates were detected and only one strain was PspA negative. Although four clonal complexes contained strains of different clades, a clear association between clade and multi locus sequence typing results was found. Clades 1, 3 and 4 were associated with a wide variety of sequence types (ST) related to multiresistant and antibiotic-susceptible worldwide-disseminated clones. Clade 1 was associated with Spain^6B-ST90, Spain¹⁴-ST18, Colombia⁵-ST289, Sweden¹-ST306, Denmark¹⁴-ST230 and Sweden¹-ST304 clones. Clade 3 was associated with Spain^23F-ST81, Spain^9V-ST156, Tennessee¹⁴-ST67, Netherlands³-ST180 and Netherlands^7F-ST191 clones. Clade 4 was related to Sweden^15A-ST63, Netherlands^18C-ST113 and Greece²¹-ST193 clones. In contrast, PspA clade was not related to serotype, age or clinical origin of the isolates.</p> <p>Conclusion</p> <p>PspA clades were associated with genotypes. PspA family 2 and family 1 were dominant among major Spanish pneumococcal clones isolated from patients with invasive disease and nasopharyngeal carriage in children.</p

Cellular and Molecular Mechanisms of Toxicity of Ingested Titanium Dioxide Nanomaterials

Funding: This work was funded by national funds through the FCT - Foundation for Science and Technology, I.P., under the project INGESTnano- PTDC/ SAU-PUB/29481/2017. Research co-funded by European Union Seventh Framework Programme (FP7/ 2007e2013) under the project NANoREG (A common European approach to the regulatory testing of nanomaterials), grant agreement 310584 and by UIDB/00009/2020; UIDP/00009/2020 (Centre for Toxicogenomics and Human Health – ToxOmics, Foundation for Science and Technology). NV holds a FCT PhD Scholarship grant (2020.07168.BD)An exponential increase in products containing titanium dioxide nanomaterials (TiO2), in agriculture, food and feed industry, lead to increased oral exposure to these nanomaterials (NMs). Thus, the gastrointestinal tract (GIT) emerges as a possible route of exposure that may drive systemic exposure, if the intestinal barrier is surpassed. NMs have been suggested to produce adverse outcomes, such as genotoxic effects, that are associated with increased risk of cancer, leading to a concern for public health. However, to date, the differences in the physicochemical characteristics of the NMs studied and other variables in the test systems have generated contradictory results in the literature. Processes like human digestion may change the NMs characteristics, inducing unexpected toxic effects in the intestine. Using TiO2 as case-study, this chapter provides a review of the works addressing the interactions of NMs with biological systems in the context of intestinal tract and digestion processes, at cellular and molecular level. The knowledge gaps identified suggest that the incorporation of a simulated digestion process for in vitro studies has the potential to improve the model for elucidating key events elicited by these NMs, advancing the nanosafety studies towards the development of an adverse outcome pathway for intestinal effects.publishersversionepub_ahead_of_prin

Molecular characterization of Streptococcus pneumoniae invasive serotype 19A isolates from adults in two Spanish regions (1994-2009)

From 1994 to 2009, the incidence of invasive serotype 19A pneumococci isolated from adults in Barcelona and San Sebastian almost doubled every 4 years. Genotyping of the 167 invasive isolates studied showed serotype 19A to be highly heterogeneous, with 35 different sequence types (STs) and a different clonal structure in each region and time period. Multiresistance, defined as non-susceptibility to three or more antimicrobials, was found in 86 (51.5%) isolates. The most frequent ST was the multidrug-resistant ST276 (n = 28), which is a single-locus variant of the Denmark14-ST230 global clone. The ST276 clone, only present in San Sebastian before 2001, was successfully disseminated from 2002 in both cities and was the main contributor to the overall increase of serotype 19A infections

Investigation of the genotoxicity of digested titanium dioxide nanomaterials in human intestinal cells

The widespread use of titanium dioxide nanomaterials (TiO2 NMs) in food and consumer products such as toothpaste or food contact materials, suggests the relevance of human oral exposure to these nanomaterials (NMs) and raises the possibility of adverse effects in the gastrointestinal tract (GIT). We previously showed that the in vitro digestion of TiO2 NMs may increase their toxicity in intestinal cells. In this work, we analyzed the genotoxicity and the intracellular reactive oxygen species induction by physiologically relevant concentrations of three different TiO2 NMs (NM-102, NM-103 and NM-105) in Caco-2 and HT29-MTX-E12 intestinal cells, while considering the potential influence of the digestion process in the NMs' physiochemical characteristics. The results evidenced a DNA-damaging effect dependent on the NM, more relevant for the rutile/anatase NM-105, possibly due to its lower hydrodynamic size in the cells medium. In addition, the results of the micronucleus assay suggest effects on chromosomal integrity, an indicator of cancer risk, in the HT29-MTX-E12 cells, for all the tested TiO2 NMs, especially after the in vitro digestion. This work supports the evidence for concerns on the use of TiO2 NMs as a food additive, recently reported by EFSA, and for their use in applications in consumer products that may drive human exposure through ingestion.This work was funded by national funds through the FCT - Foundation for Science and Technology, I.P., under the project PTDC/SAU-PUB/29481/2017. Research co-funded by UIDB/00009/2020; UIDP/00009/2020 (Centre for Toxicogenomics and Human Health – ToxOmics, FCT- Foundation for Science and Technology). NV holds a FCT PhD Scholarship grant (2020.07168.BD). iMed.ULisboa (UIDB/04138/2020 and UIDP/04138/2020) principal investigator grants CEECIND/03143/2017 (L. M. Gonçalves).info:eu-repo/semantics/publishedVersio

Invasive pneumococcal disease in healthy adults: increase of empyema associated with the clonal-type Sweden1-ST306

Background: Adult invasive pneumococcal disease (IPD) occurs mainly in the elderly and patients with co-morbidities. Little is known about the clinical characteristics, serotypes and genotypes causing IPD in healthy adults. Methods: We studied 745 culture-proven cases of IPD in adult patients aged 18-64 years (1996-2010). Patients were included in two groups: 1.) adults with co-morbidities, and 2.) healthy adults, who had no prior or coincident diagnosis of a chronic or immunosuppressive underlying disease. Microbiological studies included pneumococcal serotyping and genotyping. Results: Of 745 IPD episodes, 525 (70%) occurred in patients with co-morbidities and 220 (30%) in healthy adults. The healthy adults with IPD were often smokers (56%) or alcohol abusers (18%). As compared to patients with co-morbidities, the healthy adults had (P,0.05): younger age (43.5+/213.1 vs. 48.7+/211.3 years); higher proportions of women (45% vs.24%), pneumonia with empyema (15% vs. 7%) and infection with non-PCV7 serotypes including serotypes 1 (25% vs. 5%), 7F (13% vs. 4%), and 5 (7% vs. 2%); and lower mortality (5% vs. 20%). Empyema was more frequently caused by serotype 1. No death occurred among 79 patients with serotype 1 IPD. There was an emergence of virulent clonal-types Sweden1-ST306 and Netherlands7F-ST191. The vaccine serotype coverage with the PCV13 was higher in healthy adults than in patients with co-morbidities: 82% and 56%, respectively, P,0.001. Conclusion: In this clinical study, one-third of adults with IPD had no underlying chronic or immunosuppressive diseases (healthy adults). They were often smokers and alcohol abusers, and frequently presents with pneumonia and empyema caused by virulent clones of non-PCV7 serotypes such as the Sweden1-ST306. Thus, implementing tobacco and alcohol abuse-cessation measures and a proper pneumococcal vaccination, such as PCV13 policy, in active smokers and alcohol abusers may diminish the burden of IPD in adults

Disease isolates of Streptococcus pseudopneumoniae and non-typeable S. pneumoniae presumptively identified as atypical S. pneumoniae in Spain

We aimed to obtain insights on the nature of a collection of isolates presumptively identified as atypical Streptococcus pneumoniae recovered from invasive and non-invasive infections in Spain. One-hundred and thirty-two isolates were characterized by: optochin susceptibility in ambient and CO2-enriched atmosphere; bile solubility; PCR-based assays targeting pneumococcal genes lytA, ply, pspA, cpsA, Spn9802, aliB-like ORF2, and a specific 16S rRNA region; multilocus sequence analysis; and antimicrobial susceptibility. By multilocus sequence analysis, 61 isolates were S. pseudopneumoniae, 34 were pneumococci, 13 were S. mitis, and 24 remained unclassified as non-pneumococci. Among S. pseudopneumoniae isolates, 51 (83.6%) were collected from respiratory tract samples; eight isolates were obtained from sterile sources. High frequency of non-susceptibility to penicillin (60.7%) and erythromycin (42.6%) was found. Only 50.8% of the S. pseudopneumoniae isolates displayed the typical optochin phenotype originally described for this species. None harbored the cpsA gene or the pneumococcal typical lytA restriction fragment length polymorphism. The Spn9802 and the specific 16S rRNA regions were detected among the majority of the S. pseudopneumoniae isolates (n = 59 and n = 49, respectively). The ply and pspA genes were rarely found. A high genetic diversity was found and 59 profiles were identified. Among the S. pneumoniae, 23 were capsulated and 11 were non-typeable. Three non-typeable isolates, associated to international non-capsulated lineages, were recovered from invasive disease sources. In conclusion, half of the atypical pneumococcal clinical isolates were, in fact, S. pseudopneumoniae and one-fourth were other streptococci. We identified S. pseudopneumoniae and non-typeable pneumococci as cause of disease in Spain including invasive disease

Analysis of the Characteristics and Cytotoxicity of Titanium Dioxide Nanomaterials Following Simulated In Vitro Digestion

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Several metallic nanomaterials (NMs), such as titanium dioxide nanomaterials (TiO2), present beneficial properties with a broad range of innovative applications. The human population is exposed to TiO2, particularly by ingestion, due to its increasing use as a food additive and inclusion in dietary supplements and food packaging materials. Whether this oral exposure may lead to adverse local or systemic outcomes has been the subject of research, but studies have generated contradictory results, reflecting differences in the physicochemical properties of the TiO2 studied, effects of the surrounding matrix, and modifications during digestion. This work aimed to investigate the toxic effects of three different TiO2 NMs (NM-103, NM-103 and NM-105) on the gastrointestinal tract cells, Caco-2 and HT29-MTX-E12, after the use of the standardized static INFOGEST 2.0 in vitro digestion method to mimic human digestion of TiO2, contributing to hazard assessment. The results show that, for one of the digested TiO2 NMs studied (NM-105), a more pronounced toxicity occurs after exposure of HT29-MTX-E12 intestinal cells, as compared to undigested NM, concomitantly with subtle changes in characteristics of the NM. Thus, the inclusion of the digestion simulation in the safety evaluation of ingested NMs through in vitro bioassays can better integrate the modifications that NMs suffer in the organism. It is expected that such an approach will reduce uncertainties in the hazard assessment of ingested NMs for human health.This research was funded by the Portuguese Foundation for Science and Technology FCT/MCTES through national funds (PIDDAC), PTDC/SAU-PUB/29481/2017 and co-funded by UIDB/00009/2020 (Centre for Toxicogenomics and Human Health—ToxOmics, FCT), iMed.ULisboa (Pest-UID/DTP/04138/2019) and CESAM (UIDP/50017/2020+UIDB/50017/2020), through national funds.info:eu-repo/semantics/publishedVersio

Investigation of the genotoxicity of digested titanium dioxide nanomaterials in human intestinal cells

Funding: This work was funded by national funds through the FCT - Foundation for Science and Technology, I.P., under the project PTDC/SAUPUB/29481/2017. Research co-funded by UIDB/00009/2020; UIDP/ 00009/2020 (Centre for Toxicogenomics and Human Health – ToxOmics, FCT- Foundation for Science and Technology). NV holds a FCT PhD Scholarship grant (2020.07168.BD). iMed.ULisboa (UIDB/04138/ 2020 and UIDP/04138/2020) principal investigator grants CEECIND/ 03143/2017 (L. M. Gonçalves). The authors thank all the support from the colleagues Paula Alvito, Carla Martins and Ricardo Assunç˜ ao (Food Safety Department, INSA, Lisbon, Portugal) as well from all INGESTnano team members.The widespread use of titanium dioxide nanomaterials (TiO2 NMs) in food and consumer products such as toothpaste or food contact materials, suggests the relevance of human oral exposure to these nanomaterials (NMs) and raises the possibility of adverse effects in the gastrointestinal tract (GIT). We previously showed that the in vitro digestion of TiO2 NMs may increase their toxicity in intestinal cells. In this work, we analyzed the genotoxicity and the intracellular reactive oxygen species induction by physiologically relevant concentrations of three different TiO2 NMs (NM-102, NM-103 and NM-105) in Caco-2 and HT29-MTX-E12 intestinal cells, while considering the potential influence of the digestion process in the NMs’ physiochemical characteristics. The results evidenced a DNA-damaging effect dependent on the NM, more relevant for the rutile/anatase NM-105, possibly due to its lower hydrodynamic size in the cells medium. In addition, the results of the micronucleus assay suggest effects on chromosomal integrity, an indicator of cancer risk, in the HT29-MTX-E12 cells, for all the tested TiO2 NMs, especially after the in vitro digestion. This work supports the evidence for concerns on the use of TiO2 NMs as a food additive, recently reported by EFSA, and for their use in applications in consumer products that may drive human exposure through ingestion.publishersversionpublishe

Effects of aflatoxin B1 on intestinal cell integrity and morphology

Os autores agradecem à FCT/MCTES pelo financiamento com fundos nacionais relativos ao projeto earlyMYCO (PTDC/MED-TOX/28762/2017) e ao CESAM (UIDP/50017/2020 +UIDB/50017/2020+LA/P/0094/2020).info:eu-repo/semantics/publishedVersio

Relationship Between Biofilm Formation and Antimicrobial Resistance in Gram-Negative Bacteria

Gram-negative microorganisms are a significant cause of infection in both community and nosocomial settings. The increase, emergence, and spread of antimicrobial resistance among bacteria are the most important health problems worldwide. One of the mechanisms of resistance used by bacteria is biofilm formation, which is also a mechanism of virulence. This study analyzed the possible relationship between antimicrobial resistance and biofilm formation among isolates of three Gram-negative bacteria species. Several relationships were found between the ability to form biofilm and antimicrobial resistance, being different for each species. Indeed, gentamicin and ceftazidime resistance was related to biofilm formation in Escherichia coli, piperacillin/tazobactam, and colistin in Klebsiella pneumoniae, and ciprofloxacin in Pseudomonas aeruginosa. However, no relationship was observed between global resistance or multidrug-resistance and biofilm formation. In addition, compared with other reported data, the isolates in the present study showed higher rates of antimicrobial resistance. In conclusion, the acquisition of specific antimicrobial resistance can compromise or enhance biofilm formation in several species of Gram-negative bacteria. However, multidrug-resistant isolates do not show a trend to being greater biofilm producers than non-multiresistant isolates