The expanding antimicrobial diversity of the genus Pantoea.

With the rise of antimicrobial resistance, there is high demand for novel antimicrobials to combat multi-drug resistant pathogens. The bacterial genus Pantoea produces a diversity of antimicrobial natural products effective against a wide range of bacterial and fungal targets. These antimicrobials are synthesized by specialized biosynthetic gene clusters that have unique distributions across Pantoea as well as several other genera outside of the Erwiniaceae. Phylogenetic and genomic evidence shows that these clusters can mobilize within and between species and potentially between genera. Pantoea antimicrobials belong to unique structural classes with diverse mechanisms of action, but despite their potential in antagonizing a wide variety of plant, human, and animal pathogens, little is known about many of these metabolites and how they function. This review will explore the known antimicrobials produced by Pantoea: agglomerins, andrimid, D-alanylgriseoluteic acid, dapdiamide, herbicolins, pantocins, and the various Pantoea Natural Products (PNPs). It will include information on the structure of each compound, their genetic basis, biosynthesis, mechanism of action, spectrum of activity, and distribution, highlighting the significance of Pantoea antimicrobials as potential therapeutics and for applications in biocontrol.

Thymoquinone against infectious diseases: Perspectives in recent pandemics and future therapeutics.

The recent pandemics caused by coronavirus infections have become major challenges in 21st century human health. Scientists are struggling hard to develop a complete cure for infectious diseases, for example, drugs or vaccines against these deadly infectious diseases. We have searched papers on thymoquinone (TQ) and its effects on different infectious diseases in databases like Pubmed, Web of Science, Scopus, and Google Scholar, and reviewed them in this study. To date research suggests that natural products may become a potential therapeutic option for their prodigious anti-viral or anti-microbial effects on infectious diseases. TQ, a natural phytochemical from black seeds, is known for its health-beneficial activities against several diseases, including infections. It is evident from different in vitro and in vivo studies that TQ is effective against tuberculosis, influenza, dengue, Ebola, Zika, hepatitis, malaria, HIV, and even recent pandemics caused by severe acute respiratory syndrome of coronaviruses (SARS-CoV and SARS-CoV-2). In these cases, the molecular mechanism of TQ is partly clear but mostly obscure. In this review article, we have discussed the role of TQ against different infectious diseases, including COVID-19, and also critically reviewed the future use of TQ use to fight against infectious diseases.

Combination of Pseudo-LC-NMR and HRMS/MS-Based Molecular Networking for the Rapid Identification of Antimicrobial Metabolites From Fusarium petroliphilum.

An endophytic fungal strain isolated from a seagrass endemic to the Mediterranean Sea (Posidonia oceanica) was studied in order to identify its antimicrobial constituents and further characterize the composition of its metabolome. It was identified as Fusarium petroliphilum by in-depth phylogenetic analyses. The ethyl acetate extract of that strain exhibited antimicrobial activities and an ability to inhibit quorum sensing of Staphylococcus aureus. To perform this study with a few tens of mg of extract, an innovative one-step generic strategy was devised. On one side, the extract was analyzed by UHPLC-HRMS/MS molecular networking for dereplication. On the other side, semi-preparative HPLC using a similar gradient profile was used for a single-step high-resolution fractionation. All fractions were systematically profiled by 1H-NMR. The data were assembled into a 2D contour map, which we call "pseudo-LC-NMR," and combined with those of UHPLC-HRMS/MS. This further highlighted the connection within structurally related compounds, facilitated data interpretation, and provided an unbiased quantitative profiling of the main extract constituents. This innovative strategy led to an unambiguous characterization of all major specialized metabolites of that extract and to the localization of its bioactive compounds. Altogether, this approach identified 22 compounds, 13 of them being new natural products and six being inhibitors of the quorum sensing mechanism of S. aureus and Pseudomonas aeruginosa. Minor analogues were also identified by annotation propagation through the corresponding HRMS/MS molecular network, which enabled a consistent annotation of 27 additional metabolites. This approach was designed to be generic and applicable to natural extracts of the same polarity range.

Evaluation of Effectiveness of a Toothpaste Containing Tea Tree Oil and Ethanolic Extract of Propolis on the Improvement of Oral Health in Patients Using Removable Partial Dentures.

The aim of this study was to evaluate the effect of toothpaste containing natural tea tree essential oil (TTO) and ethanolic extract of propolis (EEP), on microflora and selected indicators of oral health in patients using removable acrylic partial dentures. Fifty patients with varying conditions of hygiene were divided into two groups. The study group received the toothpaste with TTO and EEP, while the control group received the same toothpaste but without TTO and EEP. At the first visit, oral hygiene and hygiene of the prostheses were carried out. Control visits took place 7 and 28 days later and compared to baseline. Indexes like API (Approximal Plaque Index), mSBI (modified Sulcus Bleeding Index), OHI-s (simplified Oral Hygiene Index), and DPI (Denture Plaque Index) were assessed in three subsequent stages, and swabs were collected from floor of the mouth area to assess the microbiota. After 7 and 28 days of using the toothpaste with TTO and EEP, a statistically significant decrease of the examined indicator values were observed in the study group as compared to the values upon the initial visit. The number of isolated strains of microorganisms in the study group was decreased or maintained at the same level, whereas in the control group an increase in the number of isolated strains was observed. The observed stabilization of oral microbiota in patients from the study group confirms the beneficial activity of toothpaste containing EEP and TTO compared to the control group.