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This study aimed to determine the anti-parasitic activity of the water extract obtained from Thymbra spicata (L.). The plant material was extracted with methanol in a Soxhlet apparatus. The extract was then fractionated with water and chloroform. The water phase was frozen and freeze-dried. Afterward, this extract was applied on A. castellani trophozoites and cysts at various concentrations, and the viability rates were determined by counting under the microscope. At the end of the experimental process, it was determined that there was a strong correlation between the increasing extract concentration and the anti-parasitic effect. T. spicata extract was not effective enough to neutralize all cysts at any of the concentrations examined. T. spicata extract, at concentrations of 16.0 and 32.0 mg/ml, removed all trophozoites in the medium from the 24th h of the experiment. Based on this result, it was determined that the plant species evaluated here could be used to treat A. castellani infections. It will be possible to achieve a good effect on the cyst forms of the parasite species by testing higher extract concentrations, which cannot be evaluated during the experimental process. In addition, with advanced analyzes, it will be possible to reveal the chemical substance responsible for the activity in the plant species in question and to perform further analyzes on this substance.

We report a case of Acanthamoeba castellani keratitis in a person who wore contact lenses. The amebae hosted an ameba-resistant bacterial symbiont, provisionally named “Attilina massiliensis,” a yet undescribed α-Proteobacterium.

We report a case of Acanthamoeba castellani keratitis in a person who wore contact lenses. The amebae hosted an ameba-resistant bacterial symbiont, provisionally named "Attilina massiliensis," a yet undescribed α-Proteobacterium. [ABSTRACT FROM AUTHOR]

Abstract: Limited evidence exists to suggest that the ability to invade and escape protozoan host cell bactericidal activity extends to members of the Chlamydiaceae, intracellular pathogens of humans and animals and evolutionary descendants of amoeba-resisting Chlamydia-like organisms. PCR and microscopic analyses of Chlamydophila abortus infections of Acanthamoeba castellani revealed uptake of this chlamydial pathogen but, unlike the well-described inhabitant of A. castellani, Parachlamydia acanthamoebae, Cp. abortus did not appear to propagate and is likely digested by its amoebal host. These data raise doubts about the ability of free-living amoebae to serve as hosts and vectors of pathogenic members of the Chlamydiaceae but reveal opportunities, via comparative genomics, to understand virulence mechanisms used by Chlamydia-like organisms to avoid amoebal digestion. [Copyright &y& Elsevier]

Abstract: In this study, disinfection of water containing Giardia intestinalis and Acanthamoeba castellani cysts with TiO2 and modified catalyst silver loaded TiO2 (Ag–TiO2) was investigated. Destruction of the parasites was evaluated after UV illumination of the suspension consisting 5×108–13.5×108 cysts/mL in the presence of 2g/L neat or modified TiO2 at neutral pH. In the initial stage, the solid photocatalyst particles penetrated the cyst wall and then oxidant species produced by TiO2/UV destroyed both cell wall and intracellular structure. In the case of G. intestinalis inactivation (disinfection) performance of TiO2/UV system reached 52.5% only after 25min illumination and total parasite disinfection was achieved after 30min illumination. However, silver loaded TiO2 seemed to be more effective as this loading provided better catalytic action as well as additional antimicrobial properties. Cell viability tests showed that parasite cysts, their walls in particular, were irreversibly damaged and cysts did not re-grow. Nevertheless the studied system seemed to be ineffective for the inactivation of A. castellani. Inactivation percentages of TiO2/UV and Ag–TiO2/UV systems were far lower than that of UV alone, being 50.1% and 46.1%, respectively. [Copyright &y& Elsevier]