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Highlights • The Venezuelan crisis is a regional public health threat requiring immediate action. • Ivermectin could ease the burden of Neglected Tropical Diseases in Venezuela. • Ivermectin can target parasites, viruses, and disease-transmitting vectors., For decades, Ivermectin (IVM) has been recognized as a robust antiparasitic drug with excellent tolerance and safety profiles. Historically it has been used as the drug of choice for onchocerciasis and lymphatic filariasis global elimination programs. IVM is also a standard treatment against intestinal helminths and ectoparasites given its action as an oral insecticide. The current humanitarian crisis in Venezuela is a regional public health threat that requires immediate action. Venezuela's public health system has now crumbled due to a 70% shortage of medicines in public hospitals, low vaccination campaigns, and the massive exodus of medical personnel. Herein we discuss the repurposing of IVM to attenuate the burden imposed by the most prevalent neglected tropical diseases (NTDs) in Venezuela including soil-transmitted helminths, ectoparasites and, possibly, vector-borne diseases such as malaria. Additionally, novel experimental evidence has shown that IVM is active and efficacious against Chagas disease, Leishmaniases, arboviruses, and SARS-CoV-2 in vitro. In crisis-hit Venezuela, all of the aforementioned infectious diseases are public health emergencies that have been long ignored and that also require immediate attention. IVM's versatile nature could serve as a powerful tool to tackle the multiple overlapping endemic and emergent diseases that affect Venezuela today. The repurposing of this multipurpose drug would be without a doubt a timely therapeutical approach to help mitigate the tremendous burden of NTDs nationwide.

Microbial remediation of metals can alleviate the concerns of metal pollution in the environment. The microbial remediation, however, can be a complex process since microbial metal resistance and biodiversity can play a direct role in the bioremediation process. This study aims to understand the relationships among microbial metal resistance, biodiversity, and metal sorption capacity. Meta-analyses based on 735 literature data points of minimum inhibitory concentrations (MIC) of Plantae, Bacteria, and Fungi exposed to As, Cd, Cr Cu, Ni, Pb, and Zn showed that metal resistance depends on the microbial Kingdom and the type of heavy metal and that consortia are significantly more resistant to heavy metals than pure cultures. A similar meta-analysis comparing 517 MIC values from different bacterial genera (Bacillus, Cupriavidus, Klebsiella, Ochrobactrum, Paenibacillus, Pseudomonas, and Ralstonia) confirmed that metal tolerance depends on the type of genus. Another meta-analysis with 195 studies showed that the maximum sorption capacity is influenced by microbial Kingdoms, the type of biosorbent (whether consortia or pure cultures), and the type of metal. This study also suggests that bioremediation using microbial consortia is a valid option to reduce environmental metal contaminations.

The development of functionalized nanomaterials that leads to multi-functionality, such as the ability to adsorb heavy metals coupled with anti-microbial properties is very attractive for diverse applications. The present study evaluated for the first time the antimicrobial activity of graphene oxide silanized with N-(trimethoxysilylpropyl) ethylenediamine triacetic acid (GO–EDTA) against Gram-negative, Cupriavidus metallidurans CH4, and Gram-positive bacteria, Bacillus subtilis , as well as its cytotoxicity to human corneal epithelial cell line hTCEpi. The results show that GO–EDTA has improved anti-microbial properties when compared to graphene oxide (GO) alone, with 92.3 ± 10% and 99.1 ± 1.3% cell inactivation of B. subtilis and C. metallidurans , respectively. Bacterial inactivation was attributed to an oxidative stress mechanism towards the cells. No cytotoxicity was observed towards human corneal epithelial cell lines hTCEp after 24 h exposure to GO–EDTA, suggesting that this nanomaterial has the potential for applications that have human exposure. This work also evaluated GO–EDTA’s adsorption capacity for two heavy metals, Cu 2+ and Pb 2+ at different concentrations, varying pH and contact time. The maximum adsorption capacity of the GO–EDTA was determined to be 454.6 mg g −1 and 108.7 mg g −1 for Pb 2+ and Cu 2+ , respectively, exceeding the capacity of traditional adsorbent materials, such as activated carbon.

A heavy-metal resistant bacterial consortium was obtained from a contaminated river in Sao Paulo, Brazil and utilized for the design of a fixed-bed column for the removal of copper. Prior to the design of the fixed-bed bioreactor, the copper removal capacity by the live consortium and the effects of copper in the consortium biofilm formation were investigated. The Langmuir model indicated that the sorption capacity of the consortium for copper was 450.0 mg/g dry cells. The biosorption of copper into the microbial biomass was attributed to carboxyl and hydroxyl groups present in the microbial biomass. The effect of copper in planktonic cells to form biofilm under copper rich conditions was investigated with confocal microscopy. The results revealed that biofilm formed after 72 h exposure to copper presented a reduced thickness by 57% when compared to the control; however 84% of the total cells were still alive. The fixed-bed bioreactor was set up by growing the consortium biofilm on granular activated carbon (GAC) and analyzed for copper removal. The biofilm-GAC (BGAC) column retained 45% of the copper mass present in the influent, as opposed to 17% in the control column that contained GAC only. These findings suggest that native microbial communities in sites contaminated with heavy metals can be immobilized in fixed-bed bioreactors and used to treat metal contaminated water.

It is critical to develop highly effective antimicrobial agents that are not harmful to humans and do not present adverse effects on the environment. Although antimicrobial studies of graphene-based nanomaterials are still quite limited, some researchers have paid particular attention to such nanocomposites as promising candidates for the next generation of antimicrobial agents. The polyvinyl-N-carbazole (PVK)–graphene oxide (GO) nanocomposite (PVK–GO), which contains only 3 wt% of GO well-dispersed in a 97 wt% PVK matrix, presents excellent antibacterial properties without significant cytotoxicity to mammalian cells. The high polymer content in this nanocomposite makes future large-scale material manufacturing possible in a high-yield process of adiabatic bulk polymerization. In this study, the toxicity of PVK–GO was assessed with planktonic microbial cells, biofilms, and NIH 3T3 fibroblast cells. The antibacterial effects were evaluated against two Gram-negative bacteria: Escherichia coli and Cupriavidus metallidurans; and two Gram-positive bacteria: Bacillus subtilis and Rhodococcus opacus. The results show that the PVK–GO nanocomposite presents higher antimicrobial effects than the pristine GO. The effectiveness of the PVK–GO in solution was demonstrated as the nanocomposite “encapsulated” the bacterial cells, which led to reduced microbial metabolic activity and cell death. The fact that the PVK–GO did not present significant cytotoxicity to fibroblast cells offers a great opportunity for potential applications in important biomedical and industrial fields.