Highly Stable Graphene-Based Nanocomposite (GO–PEI–Ag) with Broad-Spectrum, Long-Term Antimicrobial Activity and Antibiofilm Effects

Various silver nanoparticle (AgNP)-decorated graphene oxide (GO) nanocomposites (GO–Ag) have received increasing attention owing to their antimicrobial activity and biocompatibility; however, their aggregation in physiological solutions and the generally complex synthesis methods warrant improvement. This study aimed to synthesize a polyethyleneimine (PEI)-modified and AgNP-decorated GO nanocomposite (GO–PEI–Ag) through a facile approach through microwave irradiation without any extra reductants and surfactants; its antimicrobial activity was investigated on Gram-negative/-positive bacteria (including drug-resistant bacteria) and fungi. Compared with GO–Ag, GO–PEI–Ag acquired excellent stability in physiological solutions and electropositivity, showing substantially higher antimicrobial efficacy. Moreover, GO–PEI–Ag exhibited particularly excellent long-term effects, presenting no obvious decline in antimicrobial activity after 1 week storage in physiological saline and repeated use for three times and the lasting inhibition of bacterial growth in nutrient-rich culture medium. In contrast, GO–Ag exhibited a >60% decline in antimicrobial activity after storage. Importantly, GO–PEI–Ag effectively eliminated adhered bacteria, thereby preventing biofilm formation. The primary antimicrobial mechanisms of GO–PEI–Ag were evidenced as physical damage to the pathogen structure, causing cytoplasmic leakage. Hence, stable GO–PEI–Ag with robust, long-term antimicrobial activity holds promise in combating public-health threats posed by drug-resistant bacteria and biofilms

Spearman correlation coefficients between the number of dengue fever cases and meteorological factors, and among the meteorological factors when the minimum temperature was≥18°C.

Spearman correlation coefficients between the number of dengue fever cases and meteorological factors, and among the meteorological factors when the minimum temperature was≥18°C.</p

Mean duration of the infectious period (days) at different minimum temperature and daily survival probability.

Mean duration of the infectious period (days) at different minimum temperature and daily survival probability.</p

Additional file 1 of Characterisation of human astrovirus in a diarrhoea outbreak using nanopore and Sanger sequencing protocols

Supplementary Material

Model construction for dengue fever cases and meteorological factors.

(a) Results of model fitting for a total of 477 weeks from 2008 to 2016. The green curve indicates logit fitting. (b) Results of model prediction for the first 41 weeks of 2017. The green curve indicates the predicted dengue cases.</p

Main effects and interactive effects of meteorological factors on dengue fever from the MANOVA.

Main effects and interactive effects of meteorological factors on dengue fever from the MANOVA.</p

Minimum temperature range and cumulative number of cases.

The blue solid line indicates the trends in dengue at 2°C intervals of minimum temperature from 8–26°C. The dotted blue line represents the moving average curve.</p

Additional file 1 of Search-engine-based surveillance using artificial intelligence for early detection of coronavirus disease outbreak

Additional file 1. Table S1. Correlation coefficients of the query volumes of 32 keywords with the numbers of new cases of coronavirus disease and their query multiples (increases in query volume) from December 30, 2019 to 31 December 2019

Table_1_Topography of respiratory tract and gut microbiota in mice with influenza A virus infection.XLSX

IntroductionInfluenza A virus (IAV)-induced dysbiosis may predispose to severe bacterial superinfections. Most studies have focused on the microbiota of single mucosal surfaces; consequently, the relationships between microbiota at different anatomic sites in IAV-infected mice have not been fully studied.MethodsWe characterized respiratory and gut microbiota using full-length 16S rRNA gene sequencing by Nanopore sequencers and compared the nasopharyngeal, oropharyngeal, lung and gut microbiomes in healthy and IAV-infected mice.ResultsThe oropharyngeal, lung and gut microbiota of healthy mice were dominated by Lactobacillus spp., while nasopharyngeal microbiota were comprised primarily of Streptococcus spp. However, the oropharyngeal, nasopharyngeal, lung, and gut microbiota of IAV-infected mice were dominated by Pseudomonas, Escherichia, Streptococcus, and Muribaculum spp., respectively. Lactobacillus murinus was identified as a biomarker and was reduced at all sites in IAV-infected mice. The microbiota composition of lung was more similar to that of the nasopharynx than the oropharynx in healthy mice.DiscussionThese findings suggest that the main source of lung microbiota in mice differs from that of adults. Moreover, the similarity between the nasopharyngeal and lung microbiota was increased in IAV-infected mice. We found that IAV infection reduced the similarity between the gut and oropharyngeal microbiota. L. murinus was identified as a biomarker of IAV infection and may be an important target for intervention in post-influenza bacterial superinfections.</p

Data_Sheet_1_Coexistence of Two blaNDM–5 Genes Carried on IncX3 and IncFII Plasmids in an Escherichia coli Isolate Revealed by Illumina and Nanopore Sequencing.docx

The emergence of carbapenem-resistant Enterobacteriaceae poses a significant threat to public health worldwide. Here, we reported a multidrug-resistant Escherichia coli strain with two different blaNDM–5-carrying plasmids from China. Illumina short-read and MinION long-read whole genome sequencing were performed. Genomic analysis found that one blaNDM–5 gene together with mphA was located on a 55-kb IncX3 plasmid, while the other blaNDM–5 gene was on a novel 68-kb IncFII plasmid. Susceptibility testing and quantitative reverse transcription PCR results further indicated that the transconjugants with the IncX3 plasmid exhibited higher-level carbapenem resistance and expression of blaNDM–5 than those with both plasmids or the IncFII plasmid. Two other β-lactamase genes (blaCTX–M–15 and blaOXA–1) were also detected on another 160-kb IncF plasmid. This is the first report of coexistence of two blaNDM–5-carrying plasmids in a single bacterial isolate, highlighting the genetic complexity of NDM-5 carbapenemase circulation, and the urgent need for continued active surveillance.</p