Drug resistant parasites and fungi from a one-health perspective: A global concern that needs transdisciplinary stewardship programs

An UHPLC-MS/MS method for the determination of antiparasitic drugs, including avermectins, in avian eggs, featuring a novel standard addition approach to validation

Antiparasitic drugs have widespread use in livestock to control parasitic infections. Their use can lead to residues in animal-derived food products, which can pose potential health risks to consumers. Therefore, a method has been developed for the semi-quantitative screening of 51 antiparasitic drug residues in avian eggs, using a QuEChERS based extraction method and analysis by UHPLC-MS/MS. This extension to coverage of these analytes also includes an approach to the analysis of the traditionally difficult avermectin class of analytes using source optimisation and post-column infusion. The method was validated according to CIR (EU) 2021/808 and the detection capability (CCβ) was set at 5 µg kg-1 for all analytes, except fipronil and its metabolites, at 1.25 µg kg-1. Additionally, a novel standard addition based confirmatory method for 10 analytes with MRL values was implemented, in accordance with EURL guidance.

Progress and Prospects of Triazoles in Advanced Therapies for Parasitic Diseases

Parasitic diseases represent a severe global burden, with current treatments often limited by toxicity, drug resistance, and suboptimal efficacy in chronic infections. This review examines the emerging role of triazole-based compounds, originally developed as antifungals, in advanced antiparasitic therapy. Their unique structural properties, particularly those of 1,2,3- and 1,2,4-triazole isomers, facilitate diverse binding interactions and favorable pharmacokinetics. By leveraging innovative synthetic approaches, such as click chemistry (copper-catalyzed azide-alkyne cycloaddition) and structure-based design, researchers have repurposed and optimized triazole scaffolds to target essential parasite pathways, including sterol biosynthesis via CYP51 and other novel enzymatic routes. Preclinical studies in models of Chagas disease, leishmaniasis, malaria, and helminth infections demonstrate that derivatives like posaconazole, ravuconazole, and DSM265 exhibit potent in vitro and in vivo activity, although their primarily static effects have limited their success as monotherapies in chronic cases. Combination strategies and hybrid molecules have demonstrated the potential to enhance efficacy and mitigate drug resistance. Despite challenges in achieving complete parasite clearance and managing potential toxicity, interdisciplinary efforts across medicinal chemistry, parasitology, and clinical research highlight the significant potential of triazoles as components of next-generation, patient-friendly antiparasitic regimens. These findings support the further optimization and clinical evaluation of triazole-based agents to improve treatments for neglected parasitic diseases.

Lessons from the "Urbanorum spp." controversy: a supposed parasite and the need for scientific rigor and quality research in Latin America

BACKGROUND

Despite insufficient parasitological and clinical evidence, infections attributed to a putative protozoan named "Urbanorum spp." have been associated with gastrointestinal disease and treated with anti-parasitic drugs.

OBJECTIVES

This study aimed to clarify the nature of "Urbanorum spp." and provide guidance for health and biomedical professionals encountering this structure in human stool, emphasising the importance of rigor and quality in biomedical research.

METHODS

Coprological analyses were employed to detect intestinal parasites, lipids, and "Urbanorum spp." in 249 samples. Samples positive for "Urbanorum spp." underwent staining with trichrome, acid-fast, and Sudan IV and contrasted with positive controls. Examination with polarised light microscopy and a fragility test using ethanol were conducted.

FINDINGS

Of the tested samples, 19.4%, 2.5% and 1.3% were positive for intestinal parasites, lipids, and "Urbanorum spp." respectively. Following trichrome and acid-fast staining, few "Urbanorum spp." structures remained intact and exhibited no discernible eukaryotic characteristics; Sudan IV stain, polarized light microscopy and fragility test approaches indicated a cholesterol-based content.

MAIN CONCLUSIONS

"Urbanorum spp." is not a protozoan parasite; therefore, antiparasitic drugs are unwarranted. This structure should be identified as lipid-based material and investigated for possible malabsorption syndrome. Rigorous scientific standards were missed in related publications and peer review, contributing to the spread of this pseudoparasitism case.

Zoonotic Agents in Farmed Fish: A Systematic Review from the Interdisciplinary Perspective of the One Health Concept

This systematic review aims to synthesize evidence on zoonotic agents in farmed fish from the interdisciplinary One Health perspective. The review followed a protocol, following the PICOS strategy, where P represents population (farmed fish), I represents intervention (fish diseases), C represents comparison (healthy fish), O represents outcome (One Health) and S represents the type of study (experimental studies). The searches were conducted in the SCOPUS, Science Direct and PubMed Central databases. Of the 400 articles identified, 23 met the inclusion criteria due to their methodological robustness. These articles focused predominantly on parasitic (60.9%) and bacterial (39.1%) zoonotic agents. The One Health approaches discussed throughout the articles included host-parasite interactions (35%), antimicrobial resistance (22%), infections and food safety (18%), nutrition and immune responses (17%), stress and immune responses (4%) and anthelmintic testing (4%). The findings indicate that high-level scientific production is often confined to specific fields, such as veterinary medicine, biological sciences and animal science/fishery resources. There is a lack of broad interdisciplinary collaboration, limiting the integration of diverse fields to improve scientific production.

Proposal of a new antimicrobial resistance notation system to improve communication

Mansoor Nabi suggests the adoption of a subscript-based notation system to enhance clarity, allowing for precise communication across human, veterinary and environmental systems.

Anti-Trypanosomatid and Antiplasmodial Activities of Alkaloids From Hippeastrum Species

Diseases caused by trypanosomatid parasites like human African trypanosomiasis (HAT), Chagas disease (CD), leishmaniasis, and malaria are persistent health problems in developing countries that still demand new drug development. The species of the Amaryllidoideae subfamily (Amaryllidaceae) represent a vast source of alkaloids with a wide range of bioactive properties, including antiparasitic effects. The aim of this study was to evaluate the antiparasitic activity of the alkaloids hamayne, 7-hydroxyclivonine, 4-O-methylnangustine, and candimine against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum parasites. The alkaloids were isolated from the leaves of Hippeastrum argentinum and Hippeastrum escoipense using several chromatographic techniques and then identified by GC-MS, UPLC-MS/MS, and NMR data. The compounds were assessed against different life cycle stages of these four parasites. Furthermore, the cytotoxic activity of the alkaloids against L6 rat skeletal myoblast cells was tested. P. falciparum was very sensible to 7-hydroxyclivonine. Candimine showed significant antiparasitic activity against all the evaluated parasites, especially T. b. rhodesiense. Candimine merits deeper research regarding its effect against trypanosomatid parasites as a lead compound for the development of alternative treatments for HAT, CD, and malaria.

Response of Fusarium oxysporum soil isolate to amphotericin B and fluconazole at the proteomic level

Fusarium oxysporum is a cross-kingdom pathogen that infects humans, animals, and plants. The primary concern regarding this genus revolves around its resistance profile to multiple classes of antifungals, particularly azoles. However, the resistance mechanism employed by Fusarium spp. is not fully understood, thus necessitating further studies to enhance our understanding and to guide future research towards identifying new drug targets. Here, we employed an untargeted proteomic approach to assess the differentially expressed proteins in a soil isolate of Fusarium oxysporum URM7401 cultivated in the presence of amphotericin B and fluconazole. In response to antifungals, URM7401 activated diverse interconnected pathways, such as proteins involved in oxidative stress response, proteolysis, and lipid metabolism. Efflux proteins, antioxidative enzymes and M35 metallopeptidase were highly expressed under amphotericin B exposure. Antioxidant proteins acting on toxic lipids, along with proteins involved in lipid metabolism, were expressed during fluconazole exposure. In summary, this work describes the protein profile of a resistant Fusarium oxysporum soil isolate exposed to medical antifungals, paving the way for further targeted research and discovering new drug targets.

Harnessing the 12 Green Chemistry Principles for Sustainable Antiparasitic Drugs: Toward the One Health Approach

Antiparasitic drug development stands as a critical endeavor in combating infectious diseases which, by affecting the well-being of humans, animals, and the environment, pose significant global health challenges. In a scenario where conventional pharmacological interventions have proven inadequate, the One Health approach, which emphasizes interdisciplinary collaboration and holistic solutions, emerges as a vital strategy. By advocating for the integration of One Health principles into the R&D pharmaceutical pipeline, this Perspective promotes green chemistry methodologies to foster the development of environmentally friendly antiparasitic drugs for both human and animal health. Moreover, it highlights the urgent need to address vector-borne parasitic diseases (VBPDs) within the context of One Health-driven sustainable development, underscoring the pivotal role of medicinal chemists in driving transformative change. Aligned with the Sustainable Development Goals (SDGs) and the European Green Deal, this Perspective explores the application of the 12 Principles of Green Chemistry as a systematic framework to guide drug discovery and production efforts in the context of VBPD. Through interdisciplinary collaboration and a constant commitment to sustainability, the field can overcome the challenges posed by VBPD while promoting global and environmental responsibility. Serving as a call to action, scientists are urged to integrate One Health concepts and green chemistry principles into routine drug development practices, thereby paving the way for a more sustainable R&D pharmaceutical pipeline for antiparasitic drugs.

Antimicrobial stewardship: a definition with a One Health perspective

Antimicrobial stewardship (AMS) is a commonly advocated approach to address antimicrobial resistance. However, AMS is often defined in different ways depending on where it is applied, such that a range of definitions is now in use. These definitions may be functional and well-structured for a given context but are often ill-adapted for collaborative work, creating difficulties for intersectoral communication on AMS and complicating the design, implementation, and evaluation of AMS interventions from a One Health perspective. Using boundary object theory, we identified three key elements common to AMS in different settings in the human and animal health sectors-a sense of collective and temporal responsibility, flexibility in scale and scope, and contextual contingency. Based on these findings, we propose a definition for antimicrobial stewardship applicable to the human and animal health sectors, intended to facilitate intersectoral communication and cooperation. Further directions of this work could include the application of the definition to develop indicators for evaluating stewardship interventions and the extension of the definition to incorporate elements pertinent to plant and ecosystem health.

Transdisciplinary approaches to addressing factors that influence antimicrobial use in dairy cattle: A scoping review

Interest in antimicrobial resistance (AMR) associated with livestock farming is increasing. During the 1990s, 30-40 academic papers a year on the use of antibiotics in dairy farming were indexed on the scientific database PubMed, but this has grown to more than 200 a year in the 2020s. Most (85%) of these papers are published in veterinary or livestock science journals. There has been a corresponding increase in social science interest in why responsible antibiotic stewardship in the livestock sector is so challenging. However, most social science insights are published in journals specific to the lead authors' field(s), missing opportunities for knowledge translation to veterinary and animal science. This threatens to inhibit the transdisciplinary One Health approaches required to tackle the problem. Between 1 June and 31 December 2021, we undertook a scoping review of papers on the use of antibiotics in dairy farming indexed in PubMed, Scopus and Web of Science. Our aim was to identify studies that incorporate social science approaches and methodologies, and to note the main field of the journal in which these studies are published. Papers were most likely to be published in veterinary science, dairy science and/or livestock science journals (61, 29 and 18 respectively out of 127 papers) and were most likely to be concerned with antibiotic use, prescribing practice, and/or diagnosis (94%, 39% and 33% of included papers respectively). Only 27% of papers meeting our inclusion criteria included a qualitative approach to understanding reasons for antibiotic use. Even fewer acknowledged underlying drivers of behaviour, whereas such reasons are frequently highlighted in social science literature. Thus, to address the global health threat from antibiotic resistance, more work is needed to bring together the disparate but equally valid disciplines, methodologies and researchers working on antibiotic use in the livestock sector.

Antibacterial Potential of Symmetrical Twin-Drug 3,6-Diaminoxanthones

Global health faces a significant issue with the rise of infectious diseases caused by bacteria, fungi, viruses, and parasites. The increasing number of multi-drug resistant microbial pathogens severely threatens public health worldwide. Antibiotic-resistant pathogenic bacteria, in particular, present a significant challenge. Therefore, there is an urgent need to identify new potential antimicrobial targets and discover new chemical entities that can potentially reverse bacterial resistance. The main goal of this research work was to create and develop a library of 3,6-disubstituted xanthones based on twin drugs and molecular extension approaches to inhibit the activity of efflux pumps. The process involved synthesizing 3,6-diaminoxanthones through the reaction of 9-oxo-9H-xanthene-3,6-diyl bis(trifluoromethanesulfonate) with various primary and secondary amines. The resulting 3,6-disubstituted xanthone derivatives were then tested for their in vitro antimicrobial properties against a range of pathogenic strains and their efficacy in inhibiting the activity of efflux pumps, biofilm formation, and quorum-sensing. Several compounds have exhibited effective antibacterial properties against the Gram-positive bacterial species tested. Xanthone 16, in particular, has demonstrated exceptional efficacy with a remarkable MIC of 11 µM (4 µg/mL) against reference strains Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212, and 25 µM (9 µg/mL) against methicillin-resistant S. aureus 272123. Furthermore, some derivatives have shown potential as antibiofilm agents in a crystal violet assay. The ethidium bromide accumulation assay pinpointed certain compounds inhibiting bacterial efflux pumps. The cytotoxic effect of the most promising compounds was examined in mouse fibroblast cell line NIH/3T3, and two monoamine substituted xanthone derivatives with a hydroxyl substituent did not exhibit any cytotoxicity. Overall, the nature of the substituent was critical in determining the antimicrobial spectra of aminated xanthones.

Antiparasitic stewardship: a call to action

Tweetable abstract There is an urgent need to consider antiparasitic drugs in global efforts to achieve and implement equitable and sustainable antimicrobial stewardship initiatives worldwide.

Therapeutic Potential of Marine-Derived Cyclic Peptides as Antiparasitic Agents

Parasitic diseases still compromise human health. Some of the currently available therapeutic drugs have limitations considering their adverse effects, questionable efficacy, and long treatment, which have encouraged drug resistance. There is an urgent need to find new, safe, effective, and affordable antiparasitic drugs. Marine-derived cyclic peptides have been increasingly screened as candidates for developing new drugs. Therefore, in this review, a systematic analysis of the scientific literature was performed and 25 marine-derived cyclic peptides with antiparasitic activity (1-25) were found. Antimalarial activity is the most reported (51%), followed by antileishmanial (27%) and antitrypanosomal (20%) activities. Some compounds showed promising antiparasitic activity at the nM scale, being active against various parasites. The mechanisms of action and targets for some of the compounds have been investigated, revealing different strategies against parasites.

Traditional medicinal plants in the treatment of gastrointestinal parasites in humans: A systematic review and meta-analysis of clinical and experimental evidence

Gastrointestinal (GI) parasites cause significant morbidity and mortality worldwide. The use of conventional antiparasitic drugs is often inhibited due to limited availability, side effects or parasite resistance. Medicinal plants can be used as alternatives or adjuncts to current antiparasitic therapies. This systematic review and meta-analysis aimed to critically synthesise the literature on the efficacy of different plants and plant compounds against common human GI parasites and their toxicity profiles. Searches were conducted from inception to September 2021. Of 5393 screened articles, 162 were included in the qualitative synthesis (159 experimental studies and three randomised control trials [RCTs]), and three articles were included in meta-analyses. A total of 507 plant species belonging to 126 families were tested against different parasites, and most of these (78.4%) evaluated antiparasitic efficacy in vitro. A total of 91 plant species and 34 compounds were reported as having significant in vitro efficacy against parasites. Only a few plants (n = 57) were evaluated for their toxicity before testing their antiparasitic effects. The meta-analyses revealed strong evidence of the effectiveness of Lepidium virginicum L. against Entamoeba histolytica with a pooled mean IC50 of 198.63 μg/mL (95% CI 155.54-241.72). We present summary tables and various recommendations to direct future research.

Assessment of gastrointestinal nematode anthelmintic resistance and acaricidal efficacy of fluazuron-flumethrin on sheep and goat ticks in the North West province of South Africa

Background and Aim

Anthelmintic resistance (AR) and acaricide resistance (ACR) pose great economic threat to communal livestock raised by rural communities, limiting sustainable production. This study was conducted to assess the occurrence of AR and ACR against nematodes and ticks that infest small ruminants (sheep and goats) from small-scale farming communities in the North West Province of South Africa, as well as document the associated risk factors.

Materials and Methods

The study was conducted on small-scale farming locations in two districts of the North West Province, namely, Dr. Ruth Segomotsi Mompati district and Dr. Kenneth Kaunda district, from November 2019 to March 2020. A questionnaire survey based specifically on antiparasitic treatment and related management practices was administered to 86 small-scale farmers. A fecal egg count reduction test (FECRT) was used to determine in vivo AR in small ruminants against benzimidazole (BZD), levamisole, and macrocyclic lactone on nine ruminant farms. Then, deoxyribonucleic acid was extracted from L3 larvae and resistant nematodes were identified using a polymerase chain reaction, targeting the internal transcribed spacer 2 gene. An egg hatch assay (EHA) and a larval mortality assay (LMA) were used to determine in vitro AR against thiabendazole (TBZ and BZD) in the same farms. Acaricide resistance against fluazuron-flumethrin (Drastic Deadline eXtreme) pour-on was assessed using an adult immersion test (AIT) on Rhipicephalus evertsi.

Results

Questionnaire results indicated that most farmers (89%) relied solely on anthelmintics. Farmers used visual appraisal to estimate the dosage, which is the primary cause of resistance. The FECRT revealed AR in all the farms. Egg hatch assay results revealed AR development against TBZ in all districts, with >95% of the eggs hatching at variable doses. Larval mortality assay results revealed the development of resistance against BZD, with 50% of L3 larvae surviving at different doses in all farms. Adult immersion test results indicated that fluazuron-flumethrin (>99%) exhibited high acaricidal efficacy against R. evertsi by inhibiting tick oviposition.

Conclusion

This investigation found that sheep and goats in the studied areas are developing AR to gastrointestinal parasites. The findings of in vivo tests showed resistance with fecal egg count reduction percentage of <95% or lower confidence limit of <90%. The results of EHA and LMA revealed no evidence of inhibition of egg development and larval mortality, indicating the development of resistance. Acaricide resistance was not detected against fluazuron-flumethrin, which is commonly used in the study areas. Thus, developing management methods for these economically significant livestock nematodes, including teaching small-scale farmers how to properly administer anthelmintics and acaricides to their livestock, is urgently needed.

The potential therapeutic effect of Nigella sativa and Zingiber officinale extracts versus Nitazoxanide drug against experimentally induced cryptosporidiosis in laboratory mice

In this study, the potential anti-cryptosporidial effect of Nigella sativa (black seeds) and Zingiber officinale (ginger) alcoholic extracts versus Nitazoxanide (NTZ) medication was investigated in immunosuppressed (IS) laboratory mice. Parasitological, histopathological studies were used to assess their therapeutic efficacy. Serum level and tissue expression percentage of IFN-γ was also used. Nigella extract succeeded to reduce the mean oocyst counts in the feces of immunosuppressed mice followed by NTZ. Ginger-treated ones showed the lowest reduction percentage. Nigella sativa showed the best results in terms of restoring the normal architecture of ileal epithelium in histopathological sections stained with H&E. NTZ treatment sub-groups showed mild improvement, followed by ginger-treated mice, which showed a slight improvement in small intestine microenvironment. A significant substantial rise in serum and intestinal tissue IFN-γ cytokine levels were recorded in Nigella subgroups compared to those of NTZ and ginger respectively. According to our findings Nigella sativa outperformed Nitazoxanide in terms of anti-cryptosporidial effectiveness and regeneration characteristics revealing a promising medication. When compared to the commonly used Nitazoxanide medication or Nigella extracts, the outcomes of ginger extract were suboptimal.

Study of the Effect of Antibiotics in Drinking Water on the Content of Antioxidant Compounds in Red Wines

The presence of antibiotic residues in drinking water may be a source of contamination, which could affect the diffusion of polyphenols into the wine must during the traditional fermentation process. Antibiotic residues such as ivermectin, hydroxychloroquine, ciprofloxacin, and azithromycin on the diffusion of polyphenols and anthocyanins during wine fermentation were studied. Different samples were taken at different periods (0, 48, 96, and 168 h) to analyse the total polyphenols, anthocyanin content, and antioxidant capacity, which were correlated with Peleg's equation to establish the diffusion kinetics of these compounds. The results indicated that the presence of antibiotics reduced between 40 and 50% the diffusion of the total polyphenols and monomeric anthocyanins in red wine. The use of ivermectin showed the highest kinetic parameter k₁ compared with the use of other antibiotics. This suggested that the chemical structure and molecular weight of the antibiotics could play an important role in inhibiting the metabolism of yeasts affecting the ethanol and CO₂ production. Consequently, cell membranes would be impermeable and would not allow the release of polyphenols and anthocyanins. Therefore, it is necessary to establish strategies that allow future water quality control in wine production companies.

One Health: a holistic approach for food safety in livestock

The food safety of livestock is a critical issue between animals and humans due to their complex interactions. Pathogens have the potential to spread at every stage of the animal food handling process, including breeding, processing, packaging, storage, transportation, marketing and consumption. In addition, application of the antibiotic usage in domestic animals is a controversial issue because, while they can combat food-borne zoonotic pathogens and promote animal growth and productivity, they can also lead to the transmission of antibiotic-resistant microorganisms and antibiotic-resistant genes across species and habitats. Coevolution of microbiomes may occur in humans and animals as well which may alter the structure of the human microbiome through animal food consumption. One Health is a holistic approach to systematically understand the complex relationships among humans, animals and environments which may provide effective countermeasures to solve food safety problems aforementioned. This paper depicts the main pathogen spectrum of livestock and animal products, summarizes the flow of antibiotic-resistant bacteria and genes between humans and livestock along the food-chain production, and the correlation of their microbiome is reviewed as well to advocate for deeper interdisciplinary communication and collaboration among researchers in medicine, epidemiology, veterinary medicine and ecology to promote One Health approaches to address the global food safety challenges.

An Insight into All Tested Small Molecules against Fusarium oxysporum f. sp. Albedinis: A Comparative Review

Bayoud disease affects date palms in North Africa and the Middle East, and many researchers have used various methods to fight it. One of those methods is the chemical use of synthetic compounds, which raises questions centred around the compounds and common features used to prepare targeted molecules. In this review, 100 compounds of tested small molecules, collected from 2002 to 2022 in Web of Sciences, were divided into ten different classes against the main cause of Bayoud disease pathogen Fusarium oxysporum f. sp. albedinis (F.o.a.) with structure-activity relationship (SAR) interpretations for pharmacophore site predictions as (δ^-···δ^-), where 12 compounds are the most efficient (one compound from each group). The compounds, i.e., (Z)-1-(1.5-Dimethyl-1H-pyrazole-3-yl)-3-hydroxy but-2-en-1-one 7, (Z)-3-(phenyl)-1-(1,5-dimethyl-1H-pyrazole-3-yl)-3-hydroxyprop-2-en-1-one 23, (Z)-1-(1,5-Dimethyl-1H-pyrazole-3-yl)-3-hydroxy-3-(pyridine-2-yl)prop-2-en-1-one 29, and 2,3-bis-[(2-hydroxy-2-phenyl)ethenyl]-6-nitro-quinoxaline 61, have antifungal pharmacophore sites (δ^-···δ^-) in common in N1---O4, whereas other compounds have only one δ^- pharmacophore site pushed by the donor effect of the substituents on the phenyl rings. This specificity interferes in the biological activity against F.o.a. Further understanding of mechanistic drug-target interactions on this subject is currently underway.