Morbidity and mortality of the infected patients by multidrug-resistant bacteria have increased, emphasizing the urgency of fight for the discovery of new innovative antibiotics. In this sense, natural products emerge as valuable sources of bioactive compounds. Among the biodiversity, Eryngium pristis Cham. & Schltdl. (Apiaceae Lindl.) is traditionally used to treat thrush and ulcers of throat and mouth, as diuretic and emmenagogue, but scarcely known as an antimicrobial agent. With this context in mind, the goals of this study were to investigate the metabolic profile and the antibacterial activity of ethanolic extract (EE-Ep) and hexane (HF-Ep), dichloromethane (DF-Ep), ethyl acetate (EAF-Ep) and butanol (BF-Ep) fractions from E. pristis leaves. Gas Chromatography-Mass Spectrometry (GC-MS) was performed to stablish the metabolic profile and revealed the presence of 12 and 14 compounds in EAF-Ep and HF-Ep, respectively. β-selinene, spathulenol, globulol, 2-methoxy-4-vinylphenol, α-amyrin, β-amyrin, and lupeol derivative were some of phytochemicals identified. The antibacterial activity was determined by Minimal Inhibitory Concentration (MIC) using the broth micro-dilution against eight ATCC® and five methicillin-resistant Staphylococcus aureus (MRSA) clinical strains. HF-Ep was the most effective (MIC ≤ 5,000 µg/µL), being active against the largest part of tested Gram-positive and Gram-negative bacterial strains, including MRSA, with exception of Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 9027) and (ATCC 27853). These results suggest that E. pristis is a natural source of bioactive compounds for the search of new antibiotics which can be an interesting therapeutic approach to recover patients mainly infected by MRSA strains.

The emergence of SARS-CoV-2 variants can affect their detection via RT-qPCR. The Omicron variant has a greater affinity for the upper respiratory system and causes clinical conditions similar to bronchitis, as opposed to the pneumonitis-like conditions caused by other SARS-CoV-2 variants. This characteristic increases the viscosity of clinical samples collected for diagnosis. Coinciding with the arrival of the Omicron variant, we observed a failure in control gene expression in our laboratory. In this report, we have optimized a rapid nucleic acid extraction step to restore gene expression and detect the presence of the SARS-CoV-2 virus. We reevaluated 3000 samples, compared variant types occurring in different time periods, and confirmed that the presence of the Omicron variant was responsible for changes observed in the characteristics of these clinical samples. For samples with large amounts of mucus, such as those containing the Omicron variant, a modification to the nucleic acid extraction step was sufficient to restore the quality of RT-qPCR results.

Polygonum hydropiperoides Michx. is an Asian native plant species that is also widely distributed in the Americas. Despite its traditional uses, P. hydropiperoides is scarcely scientifically exploited. This study aimed to chemically characterize and investigate the antioxidant and antibacterial activities of hexane (HE-Ph), ethyl acetate (EAE-Ph), and ethanolic (EE-Ph) extracts from aerial parts of P. hydropiperoides. The chemical characterization was performed through HPLC-DAD-ESI/MSn. The antioxidant activity was assessed by the phosphomolybdenum reducing power, nitric oxide inhibition, and the β-carotene bleaching assays. The antibacterial activity was determined by the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration followed by the classification of the antibacterial effect. Chemical characterization revealed the expressive presence of phenolic acids and flavonoids in EAE-Ph. An increased antioxidant capacity was revealed in EAE-Ph. Regarding antibacterial activity, EAE-Ph showed weak to moderate property against 13 strains tested with MIC values ranging from 625 to 5000 µg/mL, with bactericidal or bacteriostatic effects. Glucogallin and gallic acid stand out as the most relevant bioactive compounds. These results suggest that P. hydropiperoides is a natural source of active substances, supporting this species’ traditional use.