RESUMO
In view of the current Coronavirus Disease 2019 (COVID-19) pandemic outbreak, the research community is focusing on development of diagnostics, treatment, and vaccines to halt or reverse this scenario. Although there are already various vaccines available, adaptive mutations in the SARS-CoV-2 genome can alter its pathogenic potential and, at the same time, increase the difficulty of developing drugs or immunization by vaccines. Nanotechnology carries a potential to act in all stages in fighting this viral disease, with several possibilities of strategies such as applying nanoparticles directly as antivirals in delivery systems against these viruses or incorporating them in materials, with power of achievement in therapeutics, vaccines and prevention. In this paper, we review and bring insights of recent studies using metal nanocomposites as antivirals against coronavirus and structurally similar viruses.
RESUMO
To establish a successful infection, microorganisms have developed strategies to invade host cells. One of the most important human pathogens and the greatest cause of urinary tract infections, Escherichia coli, still do not have its invasion mechanisms fully understood. This work aims to present a new approach for detecting bacterial invasion of lineage cells, based on an enzymatic-fluorogenic method. The focus of this technique is the detection of E. coli invasion of HeLa cells, exploring ß-glucuronidase, a specific constitutive enzyme of this bacterium. This enzyme hydrolyses the key substrate of this work, 4-methylumbelliferyl-ß-d-glucuronide (MUG), resulting in a fluorogenic molecule, 4-methylumbelliferone. The fluorescence curve created by this method, analyzed by Tukey statistical test, demonstrated that this detection can be efficiently performed after 5â¯h incubation with MUG. When testing uropathogenic E. coli and E. coli isolated from human gastrointestinal microbiota, the proposed method presented similar results to those exhibited by plate counting invasion detection. Data examination by Duncan statistical test allowed the creation of an intensity range of bacterial invasion, which is part of the process of results interpretation. Detection by this enzymatic-fluorogenic method, compared to other existing bacterial invasion detection techniques, is less burdensome, more sensitive and allows fast achievement of reliable results.