Tannic acid-modified silver nanoparticles as a novel therapeutic agent against Acanthamoeba.

Free-living amoebae belonging to Acanthamoeba genus are widely distributed protozoans which are able to cause infection in humans and other animals such as keratitis and encephalitis. Acanthamoeba keratitis is a vision-threatening corneal infection with currently no available fully effective treatment. Moreover, the available therapeutic options are insufficient and are very toxic to the eye.

Leishmanicidal activity of α-bisabolol from Tunisian chamomile essential oil.

According to the World Health Organization, leishmaniasis is considered as a major neglected tropical disease causing an enormous impact on global public health. Available treatments were complicated due to the high resistance, toxicity, and high cost. Therefore, the search for novel sources of anti-leishmania agents is an urgent need.

Activity of Seeds Against a Clinical Strain of Genotype T4.

keratitis (AK) is a sight-threatening infection of the cornea disease that often presents with a lengthy and not fully effective treatment. Current therapeutic options against are not very effective against the cyst. Calibrated trophozoite/cyst suspension was incubated with the same volume of serial dilutions of the aqueous extract (200, 250, 350, 450, 600, and 750 mg/mL) in microcentrifuge tubes and mixed by pipetting up and down.

Presence of Acanthamoeba in the ocular surface in a Spanish population of contact lens wearers.

Pathogenic strains of Acanthamoeba are causative agents of a sight-threatening infection of the cornea known as Acanthamoeba keratitis (AK) which mainly affects contact lens wearers and it is commonly related to poor hygiene of contact lenses and their cases. Moreover, treatment of AK is complex due to the existence of a highly resistant cyst stage and if not diagnosed early has poor prognosis, leading to blindness and/or keratoplasty. Even though AK is increasing worldwide as well as awareness among patients and clinicians, it is still a poorly studied pathogen.

Assessment of the antiprotozoal activity of Pulicaria inuloides extracts, an Algerian medicinal plant: leishmanicidal bioguided fractionation.

The lack of an effective chemotherapy for treatment of protozoan disease urges a wide investigation for active compounds, and plant-derived compounds continue to provide key leads for therapeutic agents. The current study reports the in vitro antiprotozoal evaluation of the Algerian medicinal plant Pulicaria inuloides against Leishmania amazonensis, Trypanosoma cruzi, and Acanthamoeba castellanii str. Neff.

Potentially pathogenic Acanthamoeba genotype T4 isolated from dental units and emergency combination showers.

Background: Acanthamoeba is the genus of free-living amoebae that is most frequently isolated in nature. To date, 20 Acanthamoeba genotypes have been described. Genotype T4 is responsible for approximately 90% of encephalitis and keratitis cases.

Full genome sequences are key to disclose RHDV2 emergence in the Macaronesian islands.

A recent publication by Carvalho et al. in "Virus Genes" (June 2017) reported the presence of the new variant of rabbit hemorrhagic disease virus (RHDV2) in the two larger islands of the archipelago of Madeira. Based on the capsid protein sequence, the authors suggested that the high sequence identity, along with the short time spanning between outbreaks, points to dissemination from Porto Santo to Madeira.

Acanthamoeba (T4) trophozoites cross the MDCK epithelium without cell damage but increase paracellular permeability and transepithelial resistance by modifying tight junction composition.

Free-living amoebae of the genus Acanthamoeba are protozoa ubiquitously found in nature. Some species of the genus are potentially pathogenic for humans provoking keratitis in healthy individuals, often in contact lens wearers and opportunistic infections such as pneumonitis, fatal granulomatous encephalitis and skin infections, particularly in immunocompromised individuals. The pathogenic mechanisms of these amoebae are poorly understood, however it had been suggested that contact dependent mechanisms are important during invasion, regardless of the epithelia type, since amoebae penetrate epithelia separating tight junction (TJ).

Leptomyxa valladaresi n. sp. (Amoebozoa, Tubulinea, Leptomyxida), from Mount Teide, Tenerife, Spain.

Leptomyxa valladaresi was isolated from soil in a pine forest on the southern flank of Mt Teide in Tenerife, Spain. It feeds on bacteria and on a range of other amoebae, and it was possible to establish bi-axenic cultures with L. valladaresi and Acanthamoeba.

Acanthamoeba culbertsoni isolated from a clinical case with intraocular dissemination: Structure and in vitro analysis of the interaction with hamster cornea and MDCK epithelial cell monolayers.

Acanthamoeba culbertsoni trophozoites, previously isolated from a human keratitis case with severe intraocular damage, were maintained in axenic culture. Co-incubation of amoebae with MDCK cell monolayers demonstrated an apparent preference of the amoebae to introduce themselves between the cells. The trophozoites appeared to cross the cell monolayer through the tight junctions, which resulted in decreased trans-epithelial resistance (TER) measurements.

Correlation of radical-scavenging capacity and amoebicidal activity of Matricaria recutita L. (Asteraceae).

Some Acanthamoeba strains are able to cause Granulomatous Amoebic Encephalitis (GAE) and Acanthamoeba keratitis (AK) worldwide because of their pathogenicity. The treatment of Acanthamoeba infections is complicated due to the existence of a highly resistant cyst stage in their life cycle. Therefore, the elucidation of novel sources of anti-Acanthamoeba agents is an urgent need.

Type 2 diabetes mellitus BALB/c mice are more susceptible to granulomatous amoebic encephalitis: Immunohistochemical study.

Granulomatous amoebic encephalitis (GAE) is a chronic, difficult to resolve infection caused by amphizoic amoebae of the genus Acanthamoeba, which in most cases occurs in immunosuppressed persons or with chronic diseases such as diabetes. In this study, we describe the early events of A. culbertsoni infection of GAE in diabetic mice model.

Amoebicidal, antimicrobial and in vitro ROS scavenging activities of Tunisian Rubus ulmifolius Schott, methanolic extract.

The present study aimed to evaluate the activity of methanolic extract of Rubus ulmifolius Schott against the Acanthamoeba castellani Neff Strain as well as its antioxidant and antimicrobial effects. The tested extract has a good amoebicidal activity with low IC (61.785 ± 1.

In vitro activity of 1H-phenalen-1-one derivatives against Acanthamoeba castellanii Neff and their mechanisms of cell death.

Acanthamoeba is an opportunistic pathogen which is the causal agent of a sight-threatening ulceration of the cornea known as Acanthamoeba keratitis (AK) and, more rarely, an infection of the central nervous system called "granulomatous amoebic encephalitis" (GAE). The symptoms of AK are non-specific, and so it can be misdiagnosed as a viral, bacterial, or fungal keratitis. Furthermore, current therapeutic measures against AK are arduous, and show limited efficacy against the cyst stage of Acanthamoeba.

Molecular characterization of Acanthamoeba strains isolated from the oral cavity of hemodialysis patients in Iran.

Free-living amoebae (FLA) of the genus Acanthamoeba are opportunistic pathogenic agents able to cause life-threatening infections in immunosuppressed patients. Chronic kidney disease impairs adaptive and innate immunity. Thus, patients with chronic kidney disease are prone to opportunistic infections by potentially pathogenic FLA.

Proposal for a unified classification system and nomenclature of lagoviruses.

Lagoviruses belong to the Caliciviridae family. They were first recognized as highly pathogenic viruses of the European rabbit (Oryctolagus cuniculus) and European brown hare (Lepus europaeus) that emerged in the 1970-1980s, namely, rabbit haemorrhagic disease virus (RHDV) and European brown hare syndrome virus (EBHSV), according to the host species from which they had been first detected. However, the diversity of lagoviruses has recently expanded to include new related viruses with varying pathogenicity, geographic distribution and host ranges.

Bartonella in Rodents and Ectoparasites in the Canary Islands, Spain: New Insights into Host-Vector-Pathogen Relationships.

Bartonella genus is comprised of several species of zoonotic relevance and rodents are reservoirs for some of these Bartonella species. As there were no data about the range of Bartonella species circulating among rodents in the Canary Islands, our main aim was to overcome this lack of knowledge by targeting both the citrate synthase (gltA) and the RNA polymerase beta subunit (rpoB) genes. A total of 181 small mammals and 154 ectoparasites were obtained in three of the Canary Islands, namely Tenerife, La Palma, and Lanzarote.

Isolation of Naegleria fowleri from a domestic water tank associated with a fatal encephalitis in a 4 month-old Venezuelan child.

This study describes the association of household water system contamination with the pathogenic Free-Living Amoeba (FLA) Naegleria fowleri and a case of fatal Primary Amoebic Meningoencephalitis (PAM) in a child from the state of Monagas in Venezuela. Amoebae were initially identified by microscopy from a sample of cerebrospinal fluid (CSF) from the child. Direct DNA extraction and specific PCR/sequencing for N.

Amoebicidal activity of α-bisabolol, the main sesquiterpene in chamomile (Matricaria recutita L.) essential oil against the trophozoite stage of Acanthamoeba castellani Neff.

Acanthamoeba genus includes opportunistic pathogens which are distributed worldwide and are causative agents of a fatal encephalitis and severe keratitis in humans and other animals. Until present there are not fully effective therapeutic agents against this pathogen and thus the need to search for novel anti-amoebic compounds is urgent. Recently, essential oils of aromatic and medicinal plants have shown activity against Acanthamoeba strains.

Isolation and molecular characterization of a Naegleria strain from a recreational water fountain in Tenerife, Canary Islands, Spain.

Free-Living Amoebae (FLA) are widely distributed protozoa in the environment and have been isolated from many sources such as dust, soil and water. Among the pathogenic genera included in this group Acanthamoeba spp., Naegleria fowleri and Balamuthia mandrillaris have been reported to be causative agents of lethal encephalitis, disseminated infections and keratitis.

Amoebicidal Activity of Caffeine and Maslinic Acid by the Induction of Programmed Cell Death in Acanthamoeba.

Free-living amoebae of the genus are the causal agents of a sight-threatening ulceration of the cornea called keratitis, as well as the rare but usually fatal disease granulomatous amoebic encephalitis. Although there are many therapeutic options for the treatment of infections, they are generally lengthy and/or have limited efficacy. For the best clinical outcome, treatments should target both the trophozoite and the cyst stages, as cysts are known to confer resistance to treatment.

The amoebicidal activity of Ziziphus vulgaris extract and its fractions on pathogenic Acanthamoeba trophozoites and cysts.

Acanthamoeba genus includes pathogenic species which are causal agents of a severe sight-threatening infection of the eye known as Acanthamoeba keratitis (AK). Furthermore, the number of AK is worryingly increasing worldwide, mostly in contact lens users. Until present, there is a general failure to reach a fully effective treatment against AK which is mainly due to the amoebic double-walled cyst stage which forms a protective barrier against drugs.

A Review of the Current Research Trends in the Application of Medicinal Plants as a Source for Novel Therapeutic Agents Against Infections.

keratitis (AK) is a sight-threating infection of the cornea that mostly affects contact lens wearers. Until now, AK treatment remains very difficult due to the existence of a highly resistant cyst stage in the life cycle of which is extremely resistant to most of the available anti-amoebic compounds. Moreover, current treatment of AK is usually based in the combination of various therapeutic agents such as polyhexamethylene biguanide or chlorhexidine and propamidine isethionate.

Perifosine Mechanisms of Action in Leishmania Species.

Here the mechanism by which perifosine induced cell death in and is described. The drug reduced mitochondrial membrane potential and decreased cellular ATP levels while increasing phosphatidylserine externalization. Perifosine did not increase membrane permeabilization.

In vivo CNS infection model of Acanthamoeba genotype T4: the early stages of infection lack presence of host inflammatory response and are a slow and contact-dependent process.

This study was developed in order to describe the early morphological events observed during the invasion of two pathogenic strains of Acanthamoeba (genotype T4); A. castellanii and A. culbertsoni, at the olfactory meatus and cerebral, pulmonary, renal, hepatic and splenic tissues levels, an in vivo invasion study.