Unusual Vermamoeba Vermiformis Strain Isolated from Snow in Mount Teide, Tenerife, Canary Islands, Spain

Background: Free-living amoebae (FLA) are protozoa that are widely distributed in the environment mainly in water and soil related habitats. Thermophilic amoebae are among the most common FLA in water bodies, being Vermamoeba vermiformis one of the most common species reported worldwide from these sources. Interestingly, V. vermiformis has often been reported to survive at high temperatures and osmotic pressure worldwide.Materials and Methods: In this study, snow samples were collected from Mount Teide, Tenerife, Canary Islands during the winter season of 2014. The samples were culture on non nutrient agar plates and checked daily for the presence of FLA. After a week, V. vermiformis amoebae were observed in the plates incubated at room temperature and 37ºC.Results: Molecular characterization was carried out by amplifying the 18S rDNA gene and DNA sequencing, confirmed that the isolated strain belonged to Vermamoeba vermiformis species.Conclusion: To the best of our knowledge, this is the first report of Vermamoeba vermiformis isolation from such an inusual habitat (low temperatures and high altitude) and the first report of these species in the Canary islands

First Report of Vermamoeba vermiformis in the Island of El Hierro, Canary Islands, Spain

Background: Free-living amoebae (FLA) are group of protozoa distributed worldwide in many habitats mainly water and soil related sources. Some members of FLA are able to act as opportunistic pathogens and are environmental carriers of other pathogenic agents such as bacteria and viruses. Vermamoeba vermiformis is a highly abundant FLA species in water bodies and has recently gained environmental importance as it acts as a vehicle of many pathogenic bacteria such as Legionella pneumophila.Cases Report: In this study, water samples were collected from the island of El Hierro, Canary Islands, Spain during 2015. El Hierro island was designated by UNESCO as a biosphere reserve and it is currently the less populated of the Canary Islands. The water samples were culture on 2 % Non-Nutrient Agar (NNA) plates covered with a thin layer of heat killed E. coli and checked daily for the presence of FLA. After a week, V. vermiformis amoebae were observed in the plates incubated at room temperature and 37 ºC. Molecular characterization was carried out by amplifying the 18S rDNA gene and DNA sequencing, confirming that the isolated strain belonged to Vermamoeba vermiformis species.Conclusion: To the best of our knowledge, this is the first report of Vermamoeba vermiformis isolation in the island of El Hierro and the second report of this species in the Canary Islands

First Report of a Case of Prostatitis Due to Acanthamoeba in a Dog

The first case of prostatitis in a ten year old mixed breed dog due to Acanthamoeba genotype T4 is reported. The dog was suffering from kidney dysfunction and was admitted for exploration of its organs by echography. All organs were in normal conditions with the exception of the prostate which showed signs of inflammation. An ultrasound-guided puncture was thus performed for further cytological and microbiological study. When the obtained fluid was observed under the microscope, Acanthamoeba trophozoites were detected in a high number. No other pathogens were isolated. Both culture and PCR were positive for Acanthamoeba genus and the isolate was later identified as genotype T4. Unfortunately at this stage, the dog’s owner decided to reject any kind of treatment or therapy. To the best of our knowledge, this is the first report of prostatitis in a dog due to Acanthamoeba genus

Inhibition of 3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase and Application of Statins as a Novel Effective Therapeutic Approach against Acanthamoeba Infections

Acanthamoeba is an opportunistic pathogen in humans, whose infections most commonly manifest as Acanthamoeba keratitis or, more rarely, granulomatous amoebic encephalitis. Although there are many therapeutic options for the treatment of Acanthamoeba, they are generally lengthy and/or have limited efficacy. Therefore, there is a requirement for the identification, validation, and development of novel therapeutic targets against these pathogens. Recently, RNA interference (RNAi) has been widely used for these validation purposes and has proven to be a powerful tool for Acanthamoeba therapeutics. Ergosterol is one of the major sterols in the membrane of Acanthamoeba. 3-Hydroxy-3-methylglutaryl–coenzyme A (HMG-CoA) reductase is an enzyme that catalyzes the conversion of HMG-CoA to mevalonate, one of the precursors for the production of cholesterol in humans and ergosterol in plants, fungi, and protozoa. Statins are compounds which inhibit this enzyme and so are promising as chemotherapeutics. In order to validate whether this enzyme could be an interesting therapeutic target in Acanthamoeba, small interfering RNAs (siRNAs) against HMG-CoA were developed and used to evaluate the effects induced by the inhibition of Acanthamoeba HMG-CoA. It was found that HMG-CoA is a potential drug target in these pathogenic free-living amoebae, and various statins were evaluated in vitro against three clinical strains of Acanthamoeba by using a colorimetric assay, showing important activities against the tested strains. We conclude that the targeting of HMG-CoA and Acanthamoeba treatment using statins is a novel powerful treatment option against Acanthamoeba species in human disease

Global Health Priority Box: Discovering Flucofuron as a Promising Antikinetoplastid Compound

Leishmaniasis, produced by Leishmania spp., and Chagas disease, produced by Trypanosoma cruzi, affect millions of people around the world. The treatments for these pathologies are not entirely effective and produce some side effects. For these reasons, it is necessary to develop new therapies that are more active and less toxic for patients. Some initiatives, such as the one carried out by the Medicines for Malaria Venture, allow for the screening of a large number of compounds of different origins to find alternatives to the lack of trypanocide treatments. In this work, 240 compounds were tested from the Global Health Priority Box (80 compounds with confirmed activity against drug-resistant malaria, 80 compounds for screening against neglected and zoonotic diseases and diseases at risk of drug resistance, and 80 compounds with activity against various vector species) against Trypanosoma cruzi and Leishmania amazonensis. Flucofuron, a compound with activity against vectors and with previous activity reported against Staphylococcus spp. and Schistosoma spp., demonstrates activity against L. amazonensis and T. cruzi and produces programmed cell death in the parasites. Flucofuron seems to be a good candidate for continuing study and proving its use as a trypanocidal agent

Anti-COVID Drugs (MMV COVID Box) as Leishmanicidal Agents: Unveiling New Therapeutic Horizons

Leishmaniasis, a neglected tropical disease, poses a significant global health challenge, necessitating the urgent development of innovative therapies. In this study, we aimed to identify compounds from the COVID Box with potential efficacy against two Leishmania species, laying the foundation for future chemical development. Four promising molecules were discovered, demonstrating notable inhibitory effects against L. amazonensis and L. donovani. Our study revealed that bortezomib, almitrine, and terconazole induced a significant decrease in mitochondrial membrane potential, while the above compounds and ABT239 induced plasma permeability alterations, chromatin condensation, and reactive oxygen species accumulation, indicating early apoptosis in Leishmania amazonensis promastigotes, preventing inflammatory responses and tissue damage, thereby improving patient outcomes. Furthermore, ADME predictions revealed favorable pharmacokinetic profiles for all compounds, with bortezomib and ABT239 standing out as potential candidates. These compounds exhibited intestinal absorption, blood–brain barrier penetration (excluding bortezomib), and good drug-likeness for bortezomib and ABT239. Toxicity predictions for CYP-inhibition enzymes favored bortezomib as the safest candidate. In conclusion, our study identifies bortezomib as a promising aspirant for leishmaniasis treatment, demonstrating potent antiparasitic activity, favorable pharmacokinetics, and low toxicity. These findings emphasize the potential repurposing of existing drugs for neglected diseases and highlight the importance of the COVID Box in drug discovery against tropical diseases

Discovery of New Chemical Tools against Leishmania amazonensis via the MMV Pathogen Box

The protozoan parasite Leishmania causes a spectrum of diseases and there are over 1 million infections each year. Current treatments are toxic, expensive, and difficult to administer, and resistance to them is emerging. In this study, we screened the antileishmanial activity of the Pathogen Box compounds from the Medicine for Malaria Venture against Leishmania amazonensis, and compared their structures and cytotoxicity. The compounds MMV676388 (3), MMV690103 (5), MMV022029 (7), MMV022478 (9) and MMV021013 (10) exerted a significant dose-dependent inhibition effect on the proliferation of L. amazonensis promastigotes and intracellular amastigotes. Moreover, studies on the mechanism of cell death showed that compounds 3 and 5 induced an apoptotic process while the compounds 7, 9 and 10 seem to induce an autophagic mechanism. The present findings underline the potential of these five molecules as novel therapeutic leishmanicidal agents