107 research outputs found

    Características biológicas e estrutura clonal em amostras uropatogênicas de Escherichia coli

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    The aim of the present study was to determine biological characteristics such as expression of fimbriae, Congo red binding, production of hemolysin and aerobactin, adhesion to HeLa and uroepithelial cells and invasion of HeLa cells by Escherichia coli isolates obtained from patients showing clinical signs of urinary tract infection (UTI). Also, the presence of genes (apa, afa, spa) for fimbria expression and cytotoxic necrotizing factors (CNF1, CNF2) was assayed using specific primers in PCR. The data obtained were compared with the clonal relationships obtained by analysis of multilocus enzyme electrophoresis (MLEE), restriction fragment length polymorphism (RFLP) of the rDNA (ribotyping) and enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR). All isolates but one presented a combination of at least two of the characteristics studied, a fact suggesting the presence of pathogenicity islands (PAIs). Diffuse adherence type to HeLa cells was observed to occur in most of the strains, but adhesion to uroepithelial cells seems to be a more reliable test to verify pathogenicity. Although four strains seemed to be able to invade HeLa cells when assayed by light microscopy, electron microscopy studies demonstrated that these strains were not invasive. MLEE, RFLP and ERIC-PCR were able to group the isolates differently into main clusters that were not correlated with the presence of pathogenic traits.O objetivo deste trabalho foi estudar características biológicas tais como a expressão de fímbrias e adesinas, capacidade de absorção do corante Vermelho Congo, produção de hemolisina e aerobactina, adesão e invasão a células HeLa e adesão a células do epitélio urinário em amostras de Eschericia coli isoladas de pacientes com sinais clínicos de infecção do trato urinário (UTI). A presença dos genes responsáveis pela expressão de fímbrias (apa, afa e spa) e das Citotoxinas Necrotizantes CNF1, CNF2 foi avaliada por PCR. Esses dados foram comparados com a estrutura clonal das amostras obtidas por análises de isoenzimas (MLEE), Ribotipagem (RFLP) e ERIC-PCR. Com uma única exceção, os isolados apresentaram combinação de ao menos duas das características estudadas, fato que sugere a existência de Ilhas de Patogenicidade (PAIs). A maioria das amostras apresentaram um padrão difuso de aderência a células HeLa. Os resultados indicam que a capacidade de adesão a células epiteliais do sistema urinário poderia ser um teste mais específico e correlacionado à patogenicidade. Embora os estudos com microscopia óptica indicassem que quatro linhagens pudessem ser invasivas, dados de microscopia eletrônica não confirmaram tais achados. As técnicas de MLEE, Ribotipagem e ERIC-PCR separaram os isolados em diferentes grupos principais mas estes não foram correlacionados à patogenicidade

    Effect of mesoporous silica under Neisseria meningitidis transformation process: environmental effects under meningococci transformation

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    <p>Abstract</p> <p>Background</p> <p>This study aimed the use of mesoporous silica under the naturally transformable <it>Neisseria meningitidis</it>, an important pathogen implicated in the genetic horizontal transfer of DNA causing a escape of the principal vaccination measures worldwide by the capsular switching process. This study verified the effects of mesoporous silica under <it>N. meningitidis </it>transformation specifically under the capsular replacement.</p> <p>Methods</p> <p>we used three different mesoporous silica particles to verify their action in <it>N. meningitis </it>transformation frequency.</p> <p>Results</p> <p>we verified the increase in the capsular gene replacement of this bacterium with the three mesoporous silica nanoparticles.</p> <p>Conclusion</p> <p>the mesouporous silica particles were capable of increasing the capsule replacement frequency in <it>N. meningitidis</it>.</p

    Synthesis and properties of silk fibroin/Konjac glucomannan blend beads

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    Silk fibroin (SF) and konjac glucomannan (KGM) are promising materials in the biomedical field due to their low toxicity, biocompatibility, biodegradability and low immune response. Beads of these natural polymers are interesting scaffolds for biomedical applications, but their fabrication is a challenge due to their low stability and the necessary adaptation of their chemical and mechanical properties to be successfully applied. In that sense, this study aimed to synthesize a blend of silk fibroin and konjac glucomannan (SF/KGM) in the form of porous beads obtained through dripping into liquid nitrogen, with a post-treatment using ethanol. Intermolecular hydrogen bonds promoted the integration of SF and KGM. Treated beads showed higher porous size, crystallinity, and stability than untreated beads. Characterization analyses by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric (TGA), and X-ray diffraction (XDR) evidenced that ethanol treatment allows a conformational transition from silk I to silk II in SF and an increase in the KGM deacetylation. Those chemical changes significantly enhanced the mechanical resistance of SF/KGM beads in comparison to pure SF and KGM beads. Moreover, samples showed cytocompatibility with HaCaT and BALB/c 3T3 cell

    Tipificação de amostras aviárias patogênicas de Escherichia coli pela REP-PCR

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    In the present study the repetitive extragenic palindromic (REP) polymerase chain reaction (PCR) technique was used to establish the clonal variability of 49 avian Escherichia coli (APEC) strains isolated from different outbreak cases of septicemia (n=24), swollen head syndrome (n=14) and omphalitis (n=11). Thirty commensal strains isolated from poultry with no signs of these illnesses were used as control strains. The purified DNA of these strains produced electrophoretic profiles ranging from 0 to 15 bands with molecular sizes varying from 100 bp to 6.1 kb, allowing the grouping of the 79 strains into a dendrogram containing 49 REP-types. Although REP-PCR showed good discriminating power it was not able to group the strains either into specific pathogenic classes or to differentiate between pathogenic and non-pathogenic strains. On the contrary, we recently demonstrated that other techniques such as ERIC-PCR and isoenzyme profiles are appropriate to discriminate between commensal and APEC strains and also to group these strains into specific pathogenic classes. In conclusion, REP-PCR seems to be a technique neither efficient nor universal for APEC strains discrimination. However, the population clonal structure obtained with the use of REP-PCR must not be ignored particularly if one takes into account that the APEC pathogenic mechanisms are not completely understood yet.A técnica de REP (Repetitive extragenic palindrome)-PCR foi utilizada para avaliar a variabilidade genética de 49 amostras de Escherichia coli patogênicas para aves (APEC), isoladas de aves de corte (frangos) em diferentes surtos de septicemia (n=24), síndrome da cabeça inchada (n=14) e onfalite (n=11). Trinta amostras comensais, isoladas de frangos sem sinais de doença, foram utilizadas como controle. A análise do perfil eletroforético obtido por reação de REP-PCR utilizando DNA purificado das amostras evidenciou a amplificação de 0 a 15 bandas de DNA com pesos moleculares variando entre 100 pb e 6.1 Kb. A análise deste padrão permitiu a construção de um dendrograma demonstrando o agrupamento das 79 amostras em 49 perfis distintos. Embora a técnica de REP-PCR tenha apresentado grande poder discriminatório, as amostras patogênicas e não patogênicas não foram discriminadas entre si assim como não foi observado o agrupamento de amostras causadoras do mesmo tipo de doença. Por outro lado, demonstramos recentemente que outras técnicas tais como ERIC-PCR e a análise de isoenzimas foram eficientes quando utilizadas para esta mesma finalidade. Concluindo, REP-PCR parece não ser uma técnica eficiente e universal para discriminar entre amostras APEC. Porém, a estrutura clonal populacional obtida com o uso de REP-PCR não deve ser desprezada, particularmente se considerarmos que os mecanismos de patogenicidade de APEC ainda não são completamente conhecidos.6973Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Functionalization of breast implants by cyclodextrin in-situ polymerization: a local drug delivery system for augmentation mammaplasty

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    Mammaplasty is a widely performed surgical procedure worldwide, utilized for breast reconstruction, in the context of breast cancer treatment, and aesthetic purposes. To enhance post-operative outcomes and reduce risks (hematoma with required evacuation, capsular contracture, implant-associated infection and others), the controlled release of medicaments can be achieved using drug delivery systems based on cyclodextrins (CDs). In this study, our objective was to functionalize commercially available silicone breast implants with smooth and textured surfaces through in-situ polymerization of two CDs: β-CD/citric acid and 2-hydroxypropyl-β-CD/citric acid. This functionalization serves as a local drug delivery system for the controlled release of therapeutic molecules that potentially can be a preventive treatment for post-operative complications in mammaplasty interventions. Initially, we evaluated the pre-treatment of sample surfaces with O2 plasma, followed by chitosan grafting. Subsequently, in-situ polymerization using both types of CDs was performed on implants. The results demonstrated that the proposed pre-treatment significantly increased the polymerization yield. The functionalized samples were characterized using microscopic and physicochemical techniques. To evaluate the efficacy of the proposed system for controlled drug delivery in augmentation mammaplasty, three different molecules were utilized: pirfenidone (PFD) for capsular contracture prevention, Rose Bengal (RB) as anticancer agent, and KR-12 peptide (KR-12) to prevent bacterial infection. The release kinetics of PFD, RB, and KR-12 were analyzed using the Korsmeyer-Peppas and monolithic solution mathematical models to identify the respective delivery mechanisms. The antibacterial effect of KR-12 was assessed against Staphylococcus epidermidis and Pseudomonas aeruginosa, revealing that the antibacterial rate of functionalized samples loaded with KR-12 was dependent on the diffusion coefficients. Finally, due to the immunomodulatory properties of KR-12 peptide on epithelial cells, this type of cells was employed to investigate the cytotoxicity of the functionalized samples. These assays confirmed the superior properties of functionalized samples compared to unprotected implants

    Socio-Economic Variations Determine the Clinical Presentation, Aetiology and Outcome of Infective Endocarditis: a Prospective Cohort Study from the ESC-EORP EURO-ENDO (European Infective Endocarditis) Registry.

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    peer reviewedBACKGROUND: Infective endocarditis (IE) is a life-threatening disease associated with high mortality and morbidity worldwide. We sought to determine how socio-economic factors might influence its epidemiology, clinical presentation, investigation and management, and outcome, in a large international multi-centre registry. METHODS: The EurObservationalProgramme (EORP) of the European Society of Cardiology (ESC) EURO-ENDO registry comprises a prospective cohort of 3113 adult patients admitted for IE in 156 hospitals in 40 countries between January 2016 and March 2018. Patients were separated in 3 groups, according to World Bank economic stratification (Group 1 - high income [75.6%]; Group 2 - upper-middle income [15.4%]; Group 3 - lower-middle income [9.1%]). RESULTS: Group 3 patients were younger (median age [IQR]: Group 1 - 66 [53-75] years; Group 2 - 57 [41-68] years; Group 3 - 33 [26-43] years; p<0.001) with a higher frequency of smokers, intravenous drug use and human immunodeficiency virus (HIV) infection (all p<0.001) and presented later (median [IQR) days since symptom onset: Group 1 - 12 [3-35]; Group 2 - 19 [6-54]; Group 3 - 31 [12-62]; p<0.001) with a higher likelihood of developing congestive heart failure (13.6%; 11.1%; and 22.6%, respectively; p<0.001) and persistent fever (9.8%; 14.2%; 27.9%; p<0.001). Among 2157 (69.3%) patients with theoretical indication for cardiac surgery, surgery was performed less frequently in Group 3 patients (75.5%, 76.8% and 51.3%, respectively p<0.001) who also demonstrated the highest mortality (15.0%, 23.0% and 23.7%, respectively; p<0.001). CONCLUSIONS: Socio-economic factors influence the clinical profile of patients presenting with IE across the world. Despite younger age, patients from the poorest countries presented with more frequent complications and higher mortality associated with delayed diagnosis and lower use of surgery

    Quality control of B-lines analysis in stress Echo 2020

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    Background The effectiveness trial “Stress echo (SE) 2020” evaluates novel applications of SE in and beyond coronary artery disease. The core protocol also includes 4-site simplified scan of B-lines by lung ultrasound, useful to assess pulmonary congestion. Purpose To provide web-based upstream quality control and harmonization of B-lines reading criteria. Methods 60 readers (all previously accredited for regional wall motion, 53 B-lines naive) from 52 centers of 16 countries of SE 2020 network read a set of 20 lung ultrasound video-clips selected by the Pisa lab serving as reference standard, after taking an obligatory web-based learning 2-h module ( http://se2020.altervista.org ). Each test clip was scored for B-lines from 0 (black lung, A-lines, no B-lines) to 10 (white lung, coalescing B-lines). The diagnostic gold standard was the concordant assessment of two experienced readers of the Pisa lab. The answer of the reader was considered correct if concordant with reference standard reading ±1 (for instance, reference standard reading of 5 B-lines; correct answer 4, 5, or 6). The a priori determined pass threshold was 18/20 (≥ 90%) with R value (intra-class correlation coefficient) between reference standard and recruiting center) > 0.90. Inter-observer agreement was assessed with intra-class correlation coefficient statistics. Results All 60 readers were successfully accredited: 26 (43%) on first, 24 (40%) on second, and 10 (17%) on third attempt. The average diagnostic accuracy of the 60 accredited readers was 95%, with R value of 0.95 compared to reference standard reading. The 53 B-lines naive scored similarly to the 7 B-lines expert on first attempt (90 versus 95%, p = NS). Compared to the step-1 of quality control for regional wall motion abnormalities, the mean reading time per attempt was shorter (17 ± 3 vs 29 ± 12 min, p < .01), the first attempt success rate was higher (43 vs 28%, p < 0.01), and the drop-out of readers smaller (0 vs 28%, p < .01). Conclusions Web-based learning is highly effective for teaching and harmonizing B-lines reading. Echocardiographers without previous experience with B-lines learn quickly.info:eu-repo/semantics/publishedVersio

    Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study

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    Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak. Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study. Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM. Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide
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