Publications by authors named "Helvecio Povoa"

causes serious illnesses, such as pneumonia, bacteremia, and meningitis, mainly in immunocompromised individuals and those of extreme ages. Currently, pneumococcal conjugate vaccines (PCVs) are the best allies against pneumococcal diseases. In Brazil, the 10-valent and 13-valent PCVs have been available since 2010, but the threat of antimicrobial resistance persists and has been changing over time.

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Background: New drugs targeting antimicrobial resistant pathogens, including , have been challenging to evaluate in clinical trials, particularly for the non-ventilated hospital-acquired pneumonia and ventilator-associated pneumonia indications. Development of new antibacterial drugs is facilitated by preclinical animal models that could predict clinical efficacy in patients with these infections.

Methods: We report here an FDA-funded study to develop a rabbit model of non-ventilated pneumonia with by determining the extent to which the natural history of animal disease reproduced human pathophysiology and conducting validation studies to evaluate whether humanized dosing regimens of two antibiotics, meropenem and tobramycin, can halt or reverse disease progression.

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The COVID-19 pandemic and its effects on public health have urgently demanded effective health policies to avoid the spread of COVID-19. Thus, public administrators have implemented non-pharmacological and pharmacological interventions to mitigate the pandemic's impacts and strengthen health services. The aim of this ecological study is to describe the scenario of COVID-19 pandemic in a Brazilian city, during 2 years.

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Objectives: This study aimed to evaluate the antibacterial ability and cytocompatibility of a new irrigant solution for endodontic treatment composed of 10% citric acid (CA) and 1% chlorhexidine (CHX).

Methods: Thirty-five extracted single-canal human teeth were selected and de-crowned. Canal systems (n = 7/group) were infected with Enterococcus faecalis for 4 weeks and subject to irrigation with 1% CHX; 10% CA; irrigating solution 10% CA associated with 1% CHX (CACHX); 2.

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This study aimed to search for in children's deep carious dentine and characterize their virulence traits. Eight isolates from 15 carious molars identified by 16S rDNA species-specific PCR as were included. These eight isolates were subject to identification by MALDI-TOF and characterized regarding: (i) bacterial aggregation and biofilm formation on polystyrene and glass, with/without saliva, as single or dual-species (associated to ); (ii) environmental pH measurement before and after 24 h incubation; (iii) acidogenicity; (iv) gelatinase production; (v) macrophage adherence; and (vi) toxicity towards .

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Context: Nosocomial infections arise from many microorganisms, including Staphylococcus aureus.

Aims: The aim of this study is to determine the molecular epidemiology of circulating methicillin-resistant S. aureus (MRSA) clones among patients attending community and health-care facilities in Nova Friburgo, RJ, Brazil.

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This manuscript aims to highlight the risk of Ventilator-Associated Bacterial Pneumonia (VAP) in COVID-19 inpatients. The co-infection has the potential to worsen clinical condition and increase mortality in these patients, as well as to prolong and increase the costs of hospitalization. Preventing, identifying and treating early VAP can increase the chances of successful treatment in patients with COVID-19.

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In 2010, the 10-valent (PCV10) and 13-valent (PCV13) pneumococcal conjugate vaccines were introduced in Brazil to immunize children, resulting in serotype replacement. We analyzed 253 carriage isolates recovered from children aged <6 years in Brazil, including 124 and 129 isolates from the pre-PCV10/13 (December 2009-July 2010) and post-PCV10/13 (September-December 2014) periods, respectively, to investigate the prevalence of PspA families and pilus islets, potential vaccine candidates. Serotypes and resistance profiles were previously characterized.

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This study aimed to evaluate the use of antimicrobial photodynamic therapy (aPDT) as an adjunct for minimally invasive treatment (partial removal of carious tissue-PRCT) of deciduous carious tissue evaluating its efficacy in reducing microorganisms. For that, a clinical study was design including children with deciduous molars with active deep caries lesions (DCL). PRCT was performed and remaining dentin was treated with 100 μg mL methylene blue solution (5 min) and than irradiated with a low power laser emitting red light (InGaAIP-indium gallium aluminum phosphide; λ = 660 nm; 100 mW; 300 J cm ; 90 s; 9 J).

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This study evaluated antimicrobial photodynamic therapy (aPDT) as an adjunct to endodontic treatment. Ten uniradicular teeth (control group (CG) = 4 (2 and test group (TG) = 6) with primary endodontic infections, from both genders, between 17 and 65 years old, were analyzed. Microbiological samples were collected before and after chemical-mechanical instrumentation (CMI), after aPDT (for the TG), and after the removal of the temporary restorations (second session).

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Article Synopsis
  • The study investigated how thickness, color, and polishing of ethylene-vinyl-acetate (EVA) dental materials affect their surface roughness and microbial adhesion.
  • 180 EVA samples were divided into 9 groups based on these factors, then tested for surface roughness and the amount of microorganisms that could adhere to them.
  • The findings showed that specific polishing techniques could reduce surface roughness, but they did not significantly impact the number of microorganisms that attached to the material.
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Evidence indicates that major depression is accompanied by increased translocation of gut commensal Gram-negative bacteria (leaky gut) and consequent activation of oxidative and nitrosative (O&NS) pathways. This present study examined the associations among chronic apical periodontitis (CAP), root canal endotoxin levels (lipopolysaccharides, LPS), O&NS pathways, depressive symptoms, and quality of life. Measurements included advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), lipid peroxides (LOOH), -sulfhydryl (SH) groups, total radical trapping antioxidant parameter (TRAP), and paraoxonase (PON)1 activity in participants with CAP, with and without depression, as well as healthy controls (no depression, no CAP).

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This study aimed to perform a systematic review to assess the effectiveness of antimicrobial photodynamic therapy (aPDT) in the reduction of microorganisms in deep carious lesions. An electronic search was conducted in Pubmed, Web of Science, Scopus, Lilacs, and Cochrane Library, followed by a manual search. The MeSH terms, MeSH synonyms, related terms, and free terms were used in the search.

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It has been shown that bacterial exoproducts may induce airway epithelium injury. During the epithelial repair process, the respiratory epithelial cells no more establish tight junctional intercellular complexes and may be particularly susceptible to bacterial virulence factors. In this study, we analyzed the effect of Pseudomonas aeruginosa exotoxin A (ETA) at different periods of time and concentrations on 16 HBE 14o(-) human bronchial epithelial cells in culture conditions inducing a phenotype of repairing cells.

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