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Mexico stands on the first position in the world about the consumption of bottled water per cápita. The consumption has been increased due to the bad quality of the water given by the supply network and the unequal and intermittent access to it. The contamination of the bottled water by bacteria has been reported all around the world, but it has not been investigated the presence of other microorganisms, like pathogenic free-living amoebae, which can be present in the environment, furthermore they can cause infections to humans. The objective of this investigation was to determine the presence of free-living amoebae in bottled water. Water of 47 twenty-liter carboys sold in the metropolitan area of Mexico City was analyzed. Two samples from each carboy were taken, one immediately after opening it and the other when it had reached the half of its volume. The amoebae were determined by cultivation in nonnutritive agar and were identified by morphology. Thirty-one carboys were positive for the presence of amoeba, of these, twenty-one were from local water purifiers and ten were from big water purifiers. Fifteen species were found, most of them have not been reported as pathogenic. Only Acanthamoeba has been reported as an opportunistic pathogen. The presence of this amoeba represents a health risk for the people with a weakened immune system. Because of this, not only the bacteriological and physicochemical quality but also amoeba quality must be considered., México ocupa el primer lugar a nivel mundial en consumo de agua embotellada per cápita. Esto se debe a la desconfianza que existe en la población acerca de la calidad del agua de grifo y el acceso es igual e intermitente a los sistemas de agua potable. La contaminación del agua embotellada por bacterias se ha reportado alrededor del mundo, pero no se ha investigado la presencia de otros microorganismos, como las amibas de vida libre patógenas, que pueden estar en el ambiente, pero también pueden causar infecciones en el humano. El objetivo de la presente investigación fue determinar la presencia de las amibas de vida libre patógenas en agua embotellada. Se analizó el agua de 47 garrafones de 20 litros que se venden en el Área Metropolitana de la Ciudad de México. Se analizaron 2 muestras de cada garrafón, una al abrirlo y otra a la mitad del volumen. Las amibas se determinaron por cultivo en el medio agar no nutritivo y se identificaron por morfología. Treinta y un garrafones fueron positivos para la presencia de las amibas, de estos 21 fueron de purificadoras locales y 10 de purificadoras grandes. Se encontraron 15 especies de amibas, la mayoría de ellas no son patógenas, solamente del del género Acanthamoeba han reportado como patógenas oportunistas, lo que representa un riesgo para la salud de las personas con defensas bajas. Por lo que además de la calidad bacteriológica y fisicoquímica, también se debería de tomar en cuenta la calidad amebológica del agua embotellada.

The pathogenic free-living amoeba, Acanthamoeba castellanii, is responsible for a rare but deadly central nervous system infection, granulomatous amoebic encephalitis and a blinding eye disease called Acanthamoeba keratitis. Currently, a combination of biguanides, amidine, azoles and antibiotics are used to manage these infections; however, the host cell cytotoxicity of these drugs remains a challenge. Furthermore, Acanthamoeba species are capable of transforming to the cyst form to resist chemotherapy. Herein, we have developed a nano drug delivery system based on iron oxide nanoparticles conjugated with isoniazid, which were further loaded with amphotericin B (ISO-NPs-AMP) to cause potent antiamoebic effects against Acanthamoeba castellanii. The IC₅₀ of isoniazid conjugated with magnetic nanoparticles and loaded with amphotericin B was found to be 45 μg/mL against Acanthamoeba castellanii trophozoites and 50 μg/mL against cysts. The results obtained in this study have promising implications in drug discovery as these nanomaterials exhibited high trophicidal and cysticidal effects, as well as limited cytotoxicity against rat and human cells., Sunway University, American University of Sharjah

Pathogenic free-living amebae (PFLA), of which Naegleria fowleri was the predominant pathogenic species, were isolated from 6 out of 10 pools sampled from the Hamilton, Rotorua and Gisborne Health Districts. The majority of these PFLA contaminated-pools occurred in the Matamata-Taupo region, and this localized geographical distribution appeared to be influenced, in part, by the particular physical and chemical properties of the pool. 'High-risk' pools, which exhibited a high incidence of isolations of PFLA, were shown to be natural pools, i.e. soil enclosures, as opposed to concrete constructed pools. PFLA were also isolated from the soil, and it was thought that soil acted as a reservoir of PFLA. No seasonal distribution in the occurrence of PFLA in thermal pools was noticed. A comparative study on the disinfecting potential of chlorine, chlorine dioxide, ozone and deciquam 222 for PFLA showed that all 4 disinfectants possessed amebicidal properties, but only at higher levels than those normally used for disinfecting bacteria. Of the 4 disinfectants, deciquam 222 proved to be the most effective amebicide, followed by chlorine, chlorine dioxide and ozone. An immunological survey of normal human sera for the presence of antibodies to either pathogenic or non-pathogenic Naegleria and Acanthamoeba spp. established that human sera had a titre ranging between 1/5 - 1/20 for Naegleria spp. and between 1/5 - 1/80 for Acanthamoebae. No discrimination in titres was observed between blood groups or sexes and fluorescein-labelled class-specific immunoglobulins showed that these antibodies belonged mainly to both the Ig M and Ig G classes. It was also shown that fresh adult human sera, as opposed to cord or specific hyperimmune-rabbit sera, contained a heat-labile neutralizing factor which inhibited the formation of cytopathic effects (CPE) in Vero cell culture by Acanthamoeba culbertsoni, but not by N. fowleri. Homologous, as well as heterologous antigens of Naegleria spp. wer