Representatives of the genus Acanthamoeba are among the most widespread protists in the environment. They have a ubiquitous distribution and can sometimes cause quite serious pathologies in humans. The treatment ofp rotozoal infections caused by free-living amoebae is currently limited and often unsuccessful. In the presented investigation, amebicidal activity was determined against both the trophozoites and cysts of Acanthamoeba spp., which were isolated during the microbiological examination of environmental objects. The inhibitory activity of drugs in vitro was determined using the authors\' proposed method, which is based on the plaque formation phenomenon: this is initiated by free-living amoebae when cultured in agar containing the bacteria Cellulosimicrobium sp. strain bent-1. Based on a series of experimental studies, the paper proposes a reliable and inexpensive method for determining the anti-protozoal activity of medicinal agents, which will significantly complement the current screening method system when studying existing drugs, or new drugs during their development stage.

Acanthamoeba spp. can cause a sight threatening disease. At present, the current treatments used to treat Acanthamoeba spp. Infections, such as biguanide-based antimicrobials, remain inefficacious, with the appearance of resistant forms and high cytotoxicity to host cells. In this study, an initial screening was conducted against Acanthamoeba castellanii Neff and murine macrophages J774A.1 using alamarBlue™. Among the 160 compounds included in the cited box, 90% exhibited an inhibition of the parasite above 80%, while only 18.75% of the compounds inhibited the parasite with a lethality towards murine macrophage lower than 20%. Based on the amoebicidal activity, the cytotoxicity assay, and availability, Terconazole was chosen for the elucidation of the action mode in two clinical strains, Acanthamoeba culbertsoni and Acanthamoeba castellanii L10. A fluorescence image-based system and proteomic techniques were used to investigate the effect of the present azole on the cytoskeleton network and various programmed cell death features, including chromatin condensation and mitochondria dysfunction. Taking all the results together, we can suggest that Terconazole can induce programmed cell death (PCD) via the inhibition of sterol biosynthesis inhibition.

Acanthamoeba, a widely distributed free-living amoeba found in various environments, is an opportunistic pathogen responsible for causing Acanthamoeba keratitis, a condition that may lead to blindness. However, identifying the pathogenicity of Acanthamoeba is challenging due to its complex life cycle, ability to adapt to different environments, variable virulence factors, and intricate interactions with the host immune system. Additionally, the development of an effective model for studying Acanthamoeba pathogenicity is limited, hindering a comprehensive understanding of the mechanisms underlying its virulence and host interactions. The aim of this study was to develop an ex vivo model for Acanthamoeba infection using porcine eyeballs and to evaluate the pathogenicity of the Acanthamoeba isolates. Based on slit lamp and biopsy analysis, the developed ex vivo model is capable of successfully infecting Acanthamoeba within 3 days. Histopathological staining revealed that clinical isolates of Acanthamoeba exhibited greater corneal stroma destruction and invasion in this model than environmental isolates. Our results highlight the importance of an ex vivo porcine eye model in elucidating the pathogenesis of Acanthamoeba infection and its potential implications for understanding and managing Acanthamoeba-related ocular diseases.

Acanthamoeba keratitis (AK) is a severe infection of the cornea. Prevention and treatment are difficult due to the inefficacy of currently available compounds. The impact of many commonly used compounds for routine examinations of Acanthamoeba is unexplored but might offer insight useful in combatting AK. In this study, we demonstrate that sodium metabisulfite, a common preservation constituent of eye care solutions, was found to be active against Acanthamoeba trophozoites at concentrations lower than that commonly found in eye drops (IC50 0.03 mg/mL). We demonstrate that sodium metabisulfite depletes thiamine from growth medium and that Acanthamoeba is a thiamine auxotroph, requiring thiamine salvage for growth. The inhibitory effects of sodium metabisulfite can be overcome by thiamine supplementation. These results are consistent with the lack of key enzymes for thiamine biosynthesis in the genome of Acanthamoeba, an area which might prove exploitable using new or existing compounds. Indeed, this study highlights sodium metabisulfite as a useful inhibitor of Acanthamoeba castellanii trophozoites in vitro and that it acts, at least in part, by limiting available thiamine.

Acanthamoeba keratitis (AK) is a rare, sight-threating corneal infection. The disease is challenging to diagnose and treat, and the amoeba can rapidly encyst, persisting in the tissue and causing recurrences. Medical therapy is conventionally considered the first line treatment, but advanced cases could require more invasive treatments like a \"chaud\" corneal transplant. We review the incidence of severe complications in patients affected byAK. Of 439 reports screened, 158 met our inclusion criteria. Incidence of severe complications was low, with 2.21% patients developing perforation, 1% requiring evisceration/enucleation and less than 1% developing endophthalmitis. Corneal transplantation was required in 16.68% of the cases. According to our results, and considering the reported incidences of these complications in other infectious keratitis, AK patients have an overall low risk of developing perforation, endophthalmitis, and enucleation/evisceration. Nevertheless, data available in literature remain poor, and further randomized control trials are needed to confirm our findings.

Granulomatous amoebic encephalitis due to Acanthamoeba spp is a rare, near-fatal central nervous system infection. It is often seen in immunocompromised individuals. Here we describe a survivor of this infection who was co-infected with multidrug-resistant tuberculosis. He presented to us with features of meningitis and a history of chronic cough. The chest X-ray was classical for pulmonary tuberculosis. Neuroimaging was suggestive of encephalitis; herpes simplex virus PCR was negative. Cerebrospinal fluid (CSF) showed lymphocytic pleocytosis. Wet mounts revealed trophozoites of Acanthamoeba Currently, he is being treated with oral bedaquiline, levofloxacin, linezolid, clofazimine, cycloserine and pyridoxine for tuberculosis. He received intravenous amikacin and oral cotrimoxazole and fluconazole for Acanthamoeba infection for 1 month. The resolution was confirmed by repeating the CSF wet mount, culture and neuroimaging. He was then discharged with oral rifampicin, cotrimoxazole and fluconazole. He is currently under our close follow-up.

UNASSIGNED: Acanthamoeba infection is a serious public health concern, necessitating the development of effective and safe anti-Acanthamoeba chemotherapies. Poly (ADP-ribose) polymerases (PARPs) govern a colossal amount of biological processes, such as DNA damage repair, protein degradation and apoptosis. Multiple PARP-targeted compounds have been approved for cancer treatment. However, repurposing of PARP inhibitors to treat Acanthamoeba is poorly understood.
UNASSIGNED: In the present study, we attempted to fill these knowledge gaps by performing anti-Acanthamoeba efficacy assays, cell biology experiments, bioinformatics, and transcriptomic analyses.
UNASSIGNED: Using a homology model of Acanthamoeba poly (ADP-ribose) polymerases (PARPs), molecular docking of approved drugs revealed three potential inhibitory compounds: olaparib, venadaparib and AZ9482. In particular, venadaparib exhibited superior docking scores (-13.71) and favorable predicted binding free energy (-89.28 kcal/mol), followed by AZ9482, which showed a docking score of -13.20 and a binding free energy of -92.13 kcal/mol. Notably, the positively charged cyclopropylamine in venadaparib established a salt bridge (through E535) and a hydrogen bond (via N531) within the binding pocket. For comparison, AZ9482 was well stacked by the surrounding aromatic residues including H625, Y652, Y659 and Y670. In an assessment of trophozoites viability, AZ9482 exhibited a dose-and time-dependent anti-trophozoite effect by suppressing Acanthamoeba PARP activity, unlike olaparib and venadaparib. An Annexin V-fluorescein isothiocyanate/propidium iodide apoptosis assay revealed AZ9482 induced trophozoite necrotic cell death rather than apoptosis. Transcriptomics analyses conducted on Acanthamoeba trophozoites treated with AZ9482 demonstrated an atlas of differentially regulated proteins and genes, and found that AZ9482 rapidly upregulates a multitude of DNA damage repair pathways in trophozoites, and intriguingly downregulates several virulent genes. Analyzing gene expression related to DNA damage repair pathway and the rate of apurinic/apyrimidinic (AP) sites indicated DNA damage efficacy and repair modulation in Acanthamoeba trophozoites following AZ9482 treatment.
UNASSIGNED: Collectively, these findings highlight AZ9482, as a structurally unique PARP inhibitor, provides a promising prototype for advancing anti-Acanthamoeba drug research.

Pathogenic and free-living Acanthamoeba are widely distributed in the environment and have been reported to cause keratitis and universally fatal encephalitis. Primary cutaneous acanthamoebiasis caused by Acanthamoeba is exceedingly rare and presents as isolated necrotic cutaneous lesions without involvement of the cornea or central nervous system. Cutaneous acanthamoebiasis often occurs in immunocompromised patients and is likely overlooked or even misdiagnosed only by cutaneous biopsy tissue histopathological analysis. Here, we report a HIV-infected 63-year-old female with oral leukoplakia for 4 months and scattered large skin ulcers all over the body for 2 months. The cause of the cutaneous lesions was unclear through cutaneous specimens histopathological analysis, and subsequently Acanthamoeba were detected by metagenomic next-generation sequencing (mNGS), which may be the cause of cutaneous lesions. Based on the mNGS results, a pathologist subsequently reviewed the previous pathological slides and found trophozoites of Acanthamoeba so that the cause was identified, and the skin ulcers improved significantly after treatment with multi-drug combination therapy. Acanthamoeba is also a host of pathogenic microorganisms. The presence of endosymbionts enhances the pathogenicity of Acanthamoeba, and no other pathogens were reported in this case. mNGS is helpful for rapidly diagnosing the etiology of rare skin diseases and can indicate the presence or absence of commensal microorganisms.

Here, we report the isolation and genome sequencing of a new Pacmanvirus-related isolate, Tornadovirus japonicus, from the Tamagawa River in Japan. This icosahedral virus has a genome of approximately 380 kb and 465 open reading frames, including two tRNA genes. The name \"tornado\" is based on its morphological features revealed by transmission electron microscopy analysis.

Acanthamoeba spp., are ubiquitous protist which belongs to Free-Living Amoeba (FLA) group, is considered as causal agent of side-threatening keratitis or fatal encephalitis among other human infections. Besides, this parasite has been reported as host for other microorganisms important to human health such as Campylobacter spp. or Vibrio spp. among others. This role of Acanthamoeba as pathogen and environmental phagocyte has increased the reports confirming its presence in human related environments, acting as a water quality indicator. Considering the tide relationship between water and kitchen environments, and the high prevalence of Acanthamoeba in water sources, the present study aims to establish a quick and accurate protocol based on DNA extraction and a real time qPCR assay to detect Acanthamoeba spp. in dishcloths. The procedure has been validated by processing 17 used dishcloths. Our findings demonstrated the high sensitivity of the qPCR assay used which was capable of detecting up to one Acanthamoeba from an in vitro contaminated dishcloth. The protocol accurately detected 64.7% of positive samples for Acanthamoeba spp, (in 4 samples DNA concentrations corresponded to 1-102 amoebae). Our findings demonstrate the importance of FLA surveillance by efficient and sensitive methods since one amoeba is capable of colonizing human related food environments such as kitchens sinks and could be a potential source of infection.