Fate of the antiretroviral drug tenofovir in agricultural soil

Involvement of functional senescence in efavirenz-induced toxicity in fruit fly

Background

We aimed in this article to assess the likeliness of efavirenz to induce functional senescence in Drosophila melanogaster (fruit fly).

Methods

Ten different concentrations of EFV were mixed with fly food and fed to 3-day-old flies orally for a 7 day LC50 calculation. Drug concentrations from LC50 were selected for a 28 day survival to determine the duration of treatment for behavioral and biochemical assays. A 5day feeding plan was used to investigate the effects of the drug on organismal, neuromuscular, reproductive, and metabolic senescence. An in silico study was executed to decipher a molecular interaction of Drosophila enzymes glutathione-s-transferase (GST) or acetylcholinesterase (AChE) with EFV.

Results

The calculated LC50 of EFV was 118 mg/10-g fly diet. The test drug induced a significant (P < 0.05) increase in fly mortality, climbing difficulty, and procreative deficits after a 5 day oral exposure. Similarly, there were significant (P < 0.05) biochemical alterations, which suggested in vivo biochemical damage against total thiols (T-SH), SOD (superoxide dismutase), CAT (catalase), GST, AChE, and MDA (malondialdehyde) in the test flies compared to the control groups. In silico study revealed a significantly (P < 0.05) higher binding energy between EFV and the active amino acids of fly AChE and GST when compared to the substrates or standard inhibitors respectively.

Conclusion

EFV exhibited ecotoxic potentials evidenced by age-related deficits in the fly's functional integrity such as sluggish movement, procreative deficiency, increased mortality, and oxidant-antioxidant inequality. Results from in silico study suggested antagonism against GST and AChE activities as a likely mechanism of EFV-induced toxicity in the fruit fly.

Bacteria exposed to antiviral drugs develop antibiotic cross-resistance and unique resistance profiles

Antiviral drugs are used globally as treatment and prophylaxis for long-term and acute viral infections. Even though antivirals also have been shown to have off-target effects on bacterial growth, the potential contributions of antivirals to antimicrobial resistance remains unknown. Herein we explored the ability of different classes of antiviral drugs to induce antimicrobial resistance. Our results establish the previously unrecognized capacity of antivirals to broadly alter the phenotypic antimicrobial resistance profiles of both gram-negative and gram-positive bacteria Escherichia coli and Bacillus cereus. Bacteria exposed to antivirals including zidovudine, dolutegravir and raltegravir developed cross-resistance to commonly used antibiotics including trimethoprim, tetracycline, clarithromycin, erythromycin, and amoxicillin. Whole genome sequencing of antiviral-resistant E. coli isolates revealed numerous unique single base pair mutations, as well as multi-base pair insertions and deletions, in genes with known and suspected roles in antimicrobial resistance including those coding for multidrug efflux pumps, carbohydrate transport, and cellular metabolism. The observed phenotypic changes coupled with genotypic results indicate that bacteria exposed to antiviral drugs with antibacterial properties in vitro can develop multiple resistance mutations that confer cross-resistance to antibiotics. Our findings underscore the potential contribution of wide scale usage of antiviral drugs to the development and spread of antimicrobial resistance in humans and the environment.

Quantification of some ARVs' removal efficiency from wastewater using a moving bed biofilm reactor

To date, in South Africa alone, there are an estimated 4.5 million people receiving antiretroviral (ARV) therapy. This places South Africa as the country with the largest ARV therapy programme in the world. As a result, there are an increasing number of reports on the occurrence of ARVs in South African waters. Achieving efficient and bio-friendly methods for the removal of these pollutants is considered as a concern for environmental researchers. This study aims at studying the efficiency of a moving bed biofilm reactor (MBBR) system for removing ARVs from wastewater. A continuous-flow laboratory scale system was designed, built, installed, and operated at a carrier filling rate of 30%, an organic loading rate of 0.6 kg COD/m₃.d_-1 OLR, a hydraulic retention time of 18h, and a 27.8 mL/min flow rate. The systems were monitored over time for the elimination of conventional wastewater parameters i.e., Biological Oxygen Demand, Chemical Oxygen Demand, and nutrients. The results showed that the MBBR system as a bio-friendly method has high efficiency in removing Nevirapine, Tenofovir, Efavirenz, Ritonavir and Emtricitabine from the synthetic influent sample with an average removal of 62%, 74%, 94%, 94% and 95%, respectively, after 10 days of operation.

Biocatalyst developed with recovered iron-rich minerals enhances the biotransformation of SARS-CoV-2 antiviral drugs in anaerobic bioreactors

The biotransformation of the SARS-CoV-2 antiviral drugs, ribavirin and tenofovir, was studied in methanogenic bioreactors. The role of iron-rich minerals, recovered from a metallurgic effluent, on the biotransformation process was also assessed. Enrichment of anaerobic sludge with recovered minerals promoted superior removal efficiency for both antivirals (97.4 % and 94.7 % for ribavirin and tenofovir, respectively) as compared to the control bioreactor lacking minerals, which achieved 58.5 % and 37.9 % removal for the same drugs, respectively. Further analysis conducted by liquid chromatography coupled to mass spectroscopy revealed several metabolites derived from the biotransformation of both antivirals. Interestingly, tracer analysis with ¹³CH₄ revealed that anaerobic methane oxidation coupled to Fe(III) reduction occurred in the enriched bioreactor, which was reflected in a lower content of methane in the biogas produced from this system, as compared to the control bioreactor. This treatment proposal is suitable within the circular economy concept, in which recovered metals from an industrial wastewater are applied in bioreactors to create a biocatalyst for promoting the biotransformation of emerging pollutants. This strategy may be appropriate for the anaerobic treatment of wastewaters originated from hospitals, as well as from the pharmaceutical and chemical sectors.

Effects of Two Antiretroviral Drugs on the Crustacean Daphnia magna in River Water

Antiretroviral (ARVs) drugs are used to manage the human immunodeficiency virus (HIV) disease and are increasingly being detected in the aquatic environment. However, little is known about their effects on non-target aquatic organisms. Here, Daphnia magna neonates were exposed to Efavirenz (EFV) and Tenofovir (TFV) ARVs at 62.5–1000 µg/L for 48 h in river water. The endpoints assessed were mortality, immobilization, and biochemical biomarkers (catalase (CAT), glutathione S-transferase (GST), and malondialdehyde (MDA)). No mortality was observed over 48 h. Concentration- and time-dependent immobilization was observed for both ARVs only at 250–1000 µg/L after 48 h, with significant immobilization observed for EFV compared to TFV. Results for biochemical responses demonstrated that both ARVs induced significant changes in CAT and GST activities, and MDA levels, with effects higher for EFV compared to TFV. Biochemical responses were indicative of oxidative stress alterations. Hence, both ARVs could potentially be toxic to D. magna.

HIV-antiretrovirals in river water from Gauteng, South Africa: Mixed messages of wastewater inflows as source

South Africa has the highest number of people living with the human immunodeficiency virus (HIV). High usage of HIV-antiretroviral drugs (ARVs) for the treatment of the acquired immunodeficiency syndrome (AIDS) leads to the presence of ARVs in the environment. Wastewater is a major contributor of pharmaceuticals in surface and drinking water as wastewater treatment plants (WWTPs) are not designed to remove these compounds. Pharmaceuticals in the environment pose risks and the effects of ARVs on non-target organisms are largely unknown. The concentrations of ARVs in surface water upstream and downstream from WWTPs in rivers were determined. The samples were extracted by solid-phase extraction and analysed by using liquid chromatography coupled with a quadrupole time-of-flight mass spectrometer. Five ARVs were quantified, mostly in downstream samples of the WWTPs, indicating wastewater as a source of ARVs, but this was not apparent in all cases. Nevirapine, lopinavir, and efavirenz were frequently detected; the highest concentrations being lopinavir and efavirenz at 38 μg/L and 24 μg/L, respectively. Aquatic ecosystems are at risk due to the constant input of pharmaceuticals that include large amounts of everyday use and the release of ARVs. This study highlights the potential of increased water pollution worldwide should more people consume increased quantities of pharmaceuticals.

Antiretroviral Drugs in African Surface Waters: Prevalence, Analysis, and Potential Remediation

The sources, ecotoxicological impact, and potential remediation strategies of antiretroviral drugs (ARVDs) as emerging contaminants in surface waters are reviewed based on recent literature. The occurrence of ARVDs in water bodies raises concern because many communities in Africa depend on rivers for water resources. Southern Africa is a potential hotspot regarding ARVD contamination due to relatively high therapeutic application and detection thereof in water bodies. Efavirenz and nevirapine are the most persistent in effluents and are prevalent in surface water based on environmental concentrations. Whereas the highest concentration of efavirenz reported in Kenya was 12.4 µg L^-1 , concentrations as high as 119 and 140 µg L^-1 have been reported in Zambia and South Africa, respectively. Concentrations of ARVDs ranging from 670 to 34 000 ng L^-1 (influents) and 540 to 34 000 ng L^-1 (effluents) were determined in wastewater treatment plants in South Africa, compared with Europe, where reported concentrations range from less than limit of detection (LOD) to 32 ng L^-1 (influents) and less than LOD to 22 ng L^-1 (effluents). The present African-based review suggests the need for comprehensive toxicological and risk assessment of these emerging pollutants in Africa, with the intent of averting environmental hazards and the development of sustainable remediation strategies. Environ Toxicol Chem 2022;41:247-262. © 2021 SETAC.

Prospects and challenges of photocatalysis for degradation and mineralization of antiviral drugs

Among the outbreak of influenza and other pandemics such as SARS-CoV-2 recently over the globe, antiviral drugs were significantly concerned with controlling the disease and these pandemics. They have been developed for seven decades around more than 90 drugs categorized licensed to treat nine human infectious diseases. Based on their functional group, antiviral compounds will mitigate infectivity and symptoms and reduce the illness period by arresting the viral replication cycle at different stages. Antiviral drugs have been developed complexly and met many biothreat challenges due to their high biosafety level requirement. In recent years, the spreading of novel virus strains that are a threat to human life, the development in researching and manufacturing new types of antiviral drugs increases and the use by patients and clinicians have increased. Antiviral compounds have been reported only partly removed during wastewater treatment. They were available in wastewater treatment plant effluents and found in surface water from rivers and streams, underground water, and even in drinking water. Photocatalytic degradation of antiviral drugs was exploding to clear the environmental waters from the antiviral drugs. The principle of photocatalysis is based on the excitation of the catalyst material by irradiation of light. The catalyst produces free radicals under the action of photons, which will destroy the pollutants adsorbed on its surface. The photocatalytic degradation mechanism of antiviral drugs can be understood through decomposing in a heterogeneous photocatalytic system and which species are involved in the active decomposition of the drug and then photocatalytically degrading into intermediates or mineralization products. The intermediates and the reaction pathway of antiviral compound photocatalytic degradation are complicated. However, some of the degradation processes are complete, and inorganic compounds (CO₂ and H₂O) are their final products.

Antiviral drugs in aquatic environment and wastewater treatment plants: A review on occurrence, fate, removal and ecotoxicity

The environmental release of antiviral drugs is of considerable concern due to potential ecosystem alterations and the development of antiviral resistance. As a result, interest on their occurrence and fate in natural and engineered systems has grown substantially in recent years. The main scope of this review is to fill the void of information on the knowledge on the worldwide occurrence of antiviral drugs in wastewaters and natural waters and correlate their levels with their environmental fate. According to the conducted literature survey, few monitoring data exists for several European countries, such as Germany, France, and the UK. Lesser data are available for Asia, where approximately 80% of the studies focus on Japan. Several articles study the occurrence of mostly antiretroantivirals in sub-Saharan African countries, while there is a lack of data for other developing regions of the world, including the rest of Africa, South America, and the biggest part of Asia. An importantly smaller number of studies exists for North America, while no studies exist for Oceania. The against innfluenza drug oseltamivir along with its active carboxy metabolite is found to be the most studied antiviral drug. The distribution of antiviral drugs across all geographic regions varies from low ng L^-1 to high μg L^-1 levels, in some cases, even in surface waters. This overarching review reveals that monitoring of antiviral drugs is necessary, and some of those compounds may require toxicological attention, in the light of either spatial and temporal high concentration or potential antiviral resistance. Based on the information provided herein, the need for a better understanding of the water quality hazards posed by antiviral drugs existence in wastewater outputs and freshwater ecosystems is demosntrated. Finally, the future challenges concerning the occurrence, fate, and potential ecotoxicological risk to organisms posed by antiviral drug residues are discussed.

A review of selected microcontaminants and microorganisms in land runoff and tile drainage in treated sludge-amended soils

The objective of this study is to provide a snapshot of the quality of surface runoff and tile drainage in sludge-amended soil in terms of 57 microcontaminants, including pharmaceuticals, hormones and fragrances, and 5 different species of bacteria. It also discusses the main factors affecting their occurrence (soil characteristics, applied sludge load and rate, sludge application method, rain intensity and frequency). It is based on 38 investigations carried out by different research groups in Canada, Australia, the USA and Ireland. The most frequently investigated compounds were hormones, the antiseptics triclosan and triclocarban, the analgesics and anti-inflammatories acetaminophen, ibuprofen and naproxen, the antibiotic sulfamethoxazole, the lipid regulator gemfibrozil and the psychiatric drug carbamazepine. Of all the bacteria, E. coli was the most monitored species. It was found that concentrations of the studied pollutants in surface runoff and tile drainage may vary, depending on many factors. They are generally lower than those observed in the secondary municipal effluent and in surface water, but their contribution to the deterioration of surface water quality might be relevant, mainly in wide rural areas. In this context, the reported data or their ranges represent an attempt to provide reference thresholds and bands of observed concentrations for a rough estimation of the contribution made by the release of the selected pollutants into surface water bodies via surface runoff and tile drainage.

Environmental fate and ecotoxicological effects of antiretrovirals: A current global status and future perspectives

The therapeutic efficacy of antiretroviral drugs as well as challenges and side effects against the human immunodeficiency virus is well documented and reviewed. Evidence is available in literature indication that antiretrovirals are only partially transformed and become completely excreted from the human body in their original form and/or as metabolites in urine and feces. The possibility of massive release of antiretrovirals through human excreta that enters surface water through surface runoff and wastewater treatment plant effluents is now of environmental concern because the public might be experiencing chronic exposure to antiretrovirals. The primary concern of this review is limited data concerning environmental fate and ecotoxicity of antiretrovirals and their metabolites. The review aims to provide a comprehensive insight into the evaluation of antiretrovirals in environmental samples. The objective is therefore to assess the extent of analysis of antiretrovirals in environmental samples and also look at strategies including instrumentation and predictive models that have been reported in literature on the fate and ecotoxicological effects due to presence of antiretrovirals in different environmental compartments. The review also looks at current challenges and offers possible areas of exploration that could help minimize the presence of antiretrovirals in the environment.

Sorption and leaching of benzalkonium chlorides in agricultural soils

The adsorption and leaching characteristics of two commonly used benzalkonium chlorides (BACs), benzyl dimethyl dodecyl ammonium chloride (BDDA) and benzyl dimethyl tetradecyl ammonium chloride (BDTA) using three agricultural soils with varied proportions of silt, sand, clay, and organic matter were determined. BACs are cationic surfactants used in large quantities for sanitary and personal care products and are abundant in environmental samples. Adsorption isotherm data (aqueous concentration in the range of 25-150 mg L^-1) fitted the Langmuir model better than the Freundlich model. BDTA with a longer alkyl chain adsorbed more to soil compared to BDDA, and the soil with the highest percentage of clay adsorbed the most. Column tests conducted using soils amended with lime stabilised biosolids and artificial rain water at a flow rate of 0.2 mL min^-1 indicate very low leaching of BACs. Less than 1% of the available BDDA leached through sandy loam soil column with a depth of 9 cm. Therefore, the possibility of BACs to become bioavailable through leaching is very low at environmentally relevant concentrations.

Biodegradation of benzalkonium chlorides singly and in mixtures by a Pseudomonas sp. isolated from returned activated sludge

Bactericidal cationic surfactants such as quaternary ammonium compounds (QACs) are widely detected in the environment, and found at mg kg(-1) concentrations in biosolids. Although individual QACs are amenable to biodegradation, it is possible that persistence is increased for mixtures of QACs with varying structure. The present study evaluated the biodegradation of benzyl dimethyl dodecyl ammonium chloride (BDDA) singly and in the presence of benzyl dimethyl tetradecyl ammonium chloride (BDTA) using Pseudomonas sp., isolated from returned activated sludge. Growth was evaluated, as was biodegradation using (14)C and HPLC-MS methods. BDTA was more toxic to growth of Pseudomonas sp. compared to BDDA, and BDTA inhibited BDDA biodegradation. The benzyl ring of [U-(14)C-benzyl] BDDA was readily and completely mineralized. The detection of the transformation products benzyl methyl amine and dodecyl dimethyl amine in spent culture liquid was consistent with literature. Overall, this study demonstrates the antagonistic effect of interactions on biodegradation of two widely used QACs suggesting further investigation on the degradation of mixture of QACs in wastewater effluents and biosolids.

Persistence and dissipation pathways of the antidepressant sertraline in agricultural soils

Sertraline is a widely-used antidepressant that is one of the selective serotonin reuptake inhibitors. It has been detected in biosolids and effluents from sewage treatment plants. Since sertraline can reach agriculture land through the application of municipal biosolids or reclaimed water, the persistence and dissipation pathways of (3)H-sertraline were determined in laboratory incubations using three agriculture soils varying in textures and properties. The total solvent extractable radioactivity decreased in all three soils with times to dissipate 50% of material (DT50) ranging from 48.1±3.5 (loam soil) to 84.5±13.8 (clay soil) days. Two hydroxylated sertraline transformation products were identified in all three soils by high performance liquid chromatography with time-of-flight mass spectrometry (HPLC-TOF-MS), but the accumulation did not exceed 10% of the initial parent concentration. The addition of liquid municipal biosolids to the loam soil had no effect on the rate of sertraline dissipation, or production of transformation products. In summary, sertraline was persistent in agricultural soils with major dissipation pathways including the production of non-extractable soil-bound residues, and accumulation of hydroxylated transformation products. The biologically active sertraline transformation product norsertraline was not detected in soil.

Persistence of the tricyclic antidepressant drugs amitriptyline and nortriptyline in agriculture soils

Amitriptyline and nortriptyline are widely used tricyclic antidepressant drugs. They have been detected in wastewater, surface runoff, and effluents from sewage treatment plants. As such, they could potentially reach agriculture land through the application of municipal biosolids or reclaimed water. In the absence of data on their fate in the environment, the persistence and dissipation pathways of radiolabeled amitriptyline were determined in three agriculture soils varying widely in texture and chemical properties (loam soil, clay loam soil, and sandy loam soil). Tritiated amitriptyline was added to laboratory microcosms containing soils, and the metabolism of the extractable (3) H was monitored during incubation at 30°C. The total solvent extractable radioactivity decreased in all three soils with times to dissipate 50% of material (DT50) ranging from 34.1 ± 3.2 (loam soil) to 85.3 ± 3.2 d (sandy soil). Nortriptyline (N-desmethyl amitriptyline) and amitriptyline-N-oxide were identified as major transformation products in all three soils by high performance liquid chromatography with photodiode array detector and time-of-flight mass spectrometry (HPLC-TOF-MS/UV). The addition of liquid municipal biosolids to the loam soil had no effect on the dissipation of amitriptyline. The persistence of nortriptyline was evaluated in the loam soil. The DT50 of nortriptyline was 40.5 ± 3.2 d estimated with HPLC-TOF-MS/UV. Approximately 10% of added nortriptyline was converted to hydroxylated products after 50 d of incubation. In summary, amitriptyline persisted in agricultural soils with major dissipation mechanisms, including forming nonextractable residues and producing various transformation products including the psychoactive drug nortriptyline.