Antimicrobial activity of Pantanal macrophytes against multidrug resistant bacteria shows potential for improving nature-based solutions

The presence of macrophytes in constructed wetlands (CW) applied within the concept of nature-based solution (NBS) is crucial. Besides their role in the phytoremediation of pollutants, the cultivated plants, if properly selected, can also produce a range of bioactive compounds, including those with potential inhibitory effects against pathogenic bacteria. Bioactive compounds, such as flavonoids and ellagitannins, known for their remarkable antimicrobial properties, offer a sustainable solution to the global challenge of antibiotic resistance. In this study, we investigated macrophyte species adapted to the water variations in the Pantanal region (flood and dry seasons), focusing on those with both antimicrobial and ornamental potential, that could improve the ability of a CW system to treat greywater. Seven different macrophyte species were collected, cultivated, and evaluated for their antimicrobial activity (AA) against five standard bacterial strains and five multidrug-resistant clinical bacterial strains. Extracts from the leaf, stem, and root of Polygonum acuminatum showed the best AA against clinical multidrug-resistant strains of Staphylococcus aureus, Enterococcus faecium, and Escherichia coli, with minimum inhibitory concentration (MIC) values ranging from 78.13 to 312.5 µg.mL−1. Furthermore, the leaves of Ludwigia lagunae and P. acuminatum also showed considerable AA against standard strains of Enterococcus faecalis (MIC = 19.5 and 39.06 µg.mL−1, respectively) and Pseudomonas aeruginosa (MIC = 156.25 µg.mL−1 for both). High-Performance Liquid Chromatography with Ultraviolet and Mass Spectrometry analysis of these extracts identified important bioactive compounds, including flavonoids (quercetin 3-rhamnoside, hydropiperoside, quercetin 3-O-rutinoside, quercetin, myricetin 3-O-rhamnoside, kaempferol 3-O-rhamnoside, formononetin, and calycosin) and ellagitannins (3,3′4-tri-O-methylelagic acid, galloys-HHDP-glucose, and ellagic acid), along with other bioactive compounds. These results indicate that P. acuminatum and L. lagunae hold potential for application in CW owing to their antimicrobial property, local adaptability, and ornamental appeal

Antimicrobial Potential of Essential Oils from Cerrado Plants against Multidrug−Resistant Foodborne Microorganisms

Foodborne pathogens are a real public health concern in an escalating antimicrobial resistance scenario. Natural products represent a promising source of bioactive molecules, and essential oils have attracted much attention due to their myriad of biological properties, including antibacterial activities. In this context, essential oils obtained from the leaves of Chromolaena squalida, Campomanesia sessiliflora, Myrsine guianensis, Matayba guianensis, Siparuna guianensis, Ocotea minarum and Endlicheria paniculata—species from the Cerrado biome of Midwest Brazil—were extracted and evaluated for their antibacterial activity against a panel of four standard and three clinical multidrug−resistant bacterial strains. All tested oils showed moderate to good activity against at least four bacterial strains, including Salmonella Typhi and oxacillin−resistant Staphylococcus. The essential oils from C. squalida, C. sessiliflora, My. guianensis and Ma. guianensis showed strong inhibition of clinical Staphylococcus strains, which cause bovine mastitis and are related to milk−borne diseases. Their chemical profiles were investigated by gas chromatography coupled to mass spectrometry (GC/MS), which revealed a predominance of mono− and sesquiterpene hydrocarbons, some of which with well−known antimicrobial properties. The essential oil from Cerrado plants proved active against resistant Gram−positive and Gram−negative bacteria, revealing their potentialities for the development of new alternative agents to prevent the spreading of resistant bacterial contamination

Medicinal plant Miconia albicans synergizes with ampicillin and ciprofloxacin against multi-drug resistant Acinetobacter baumannii and Staphylococcus aureus

Abstract Background Given the rising occurrence of antibiotic resistance due to the existence and ongoing development of resistant bacteria and phenotypes, the identification of new treatments and sources of antimicrobial agents is of utmost urgency. An important strategy for tackling bacterial resistance involves the utilization of drug combinations, and natural products derived from plants hold significant potential as a rich source of bioactive compounds that can act as effective adjuvants. This study, therefore, aimed to assess the antibacterial potential and the chemical composition of Miconia albicans, a Brazilian medicinal plant used to treat various diseases. Methods Ethanolic extracts from leaves and stems of M. albicans were obtained and subsequently partitioned to give the corresponding hexane, chloroform, ethyl acetate, and hydromethanolic phases. All extracts and phases had their chemical constitution investigated by HPLC–DAD-MS/MS and GC–MS and were assessed for their antibiofilm and antimicrobial efficacy against Staphylococcus aureus. Furthermore, their individual effects and synergistic potential in combination with antibiotics were examined against clinical strains of both S. aureus and Acinetobacter baumannii. In addition, 10 isolated compounds were obtained from the leaves phases and used for confirmation of the chemical profiles and for antibacterial assays. Results Based on the chemical profile analysis, 32 compounds were successfully or tentatively identified, including gallic and ellagic acid derivatives, flavonol glycosides, triterpenes and pheophorbides. Extracts and phases obtained from the medicinal plant M. albicans demonstrated synergistic effects when combined with the commercial antibiotics ampicillin and ciprofloxacin, against multi-drug resistant bacteria S. aureus and A. baumannii, restoring their antibacterial efficacy. Extracts and phases also exhibited antibiofilm property against S. aureus. Three key compounds commonly found in the samples, namely gallic acid, quercitrin, and corosolic acid, did not exhibit significant antibacterial activity when assessed individually or in combination with antibiotics against clinical bacterial strains. Conclusions Our findings reveal that M. albicans exhibits remarkable adjuvant potential for enhancing the effectiveness of antimicrobial drugs against resistant bacteria

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora