Browsing by Author "Toledo, R."

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    Are human pathogenic free-living amoebae present in Leicester city’s environment (UK)?
    (2019-07-08) Anjum, U.; Magnet, A.; Acosta, L.; Toledo, R.; Pena-Fernandez, A.
    The environmental presence and distribution of human pathogenic free-living amoebae (FLA) Acanthamoeba spp., Naegleria fowleri and Balamuthia mandrillaris, have been reported in different environmental compartments and geographical locations, as they do not require a host to complete their life cycle. However, information on the environmental distribution of these opportunistic pathogens in Europe remains unclear and mostly limited to water environments in certain European countries such as Spain or Poland. The main aim was to further study the potential environmental presence of these opportunistic pathogens in Leicester in environments other than water ecosystems but that could represent a risk to the public. Forty-five samples were collected in October 2018 (5 topsoil, 5 grass and 5 animal faecal samples) from three different and frequently visited urban parks in Leicester (Castle Gardens, Victoria Park and Newalk Park). Only fresh faecal samples were selected for this study and collected on days with no previous precipitation for at least two days. A veterinarian identified the possible animal species as: 7 avian (3 waterfowl, 4 pigeon) and 8 canine (dog or possibly fox). After appropriate pre-treatment, DNA was extracted from each sample using the Fast DNA® Spin kit, following manufacturer’s methodologies. A triplex real-time TaqMan PCR assay was performed for detecting FLA using positive controls for the three amoebae, using established methodologies. All 45 environmental and animal faecal samples assessed for FLA were negative. However, our results should be considered inconclusive as, although rare, several studies have reported an increase in AK in England in recent years, which might indicate not only the presence but also the distribution of these parasites. Further monitoring studies are required to understand the presence and circulation of FLA in the English environment, particularly for Acanthamoeba spp., to inform public health decisions to prevent future infections.
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    Studying the presence and circulation of opportunistic protozoan parasites in Leicester, UK.
    (2019-07-08) Anjum, U.; Izquierdo, F.; Acosta, L.; Toledo, R.; Pena-Fernandez, A.
    A zoonotic role has been described for different opportunistic human protozoan parasites including coccidian species (Cryptosporidium spp., Cyclospora sp. and Cystoisospora sp.), Giardia intestinalis and Entamoeba histolytica. From a public health perspective, these protozoan parasites can be life threatening in immunocompromised and immunosuppressed patients. However, little is known about their presence and distribution in urban environments despite rapid development and urbanization. Our research group has detected the presence of structures related with Cryptosporidium spp., Cyclospora spp. and Giardia spp. in animal faecal samples collected in different urban parks and recreational areas in Leicester (UK) in May 2018. In these samples, either Entamoeba spp. or Cystoisospora spp. were detected. The main aim of this study was to confirm our previous results and to evaluate the potential circulation of these opportunistic pathogens in urban parks from Leicester to evaluate their risks to the population. Fifteen fresh animal faecal samples were collected in October 2018 from three frequently visited urban parks in Leicester (Castle Gardens, Victoria Park and Newalk Park). Animal droppings were collected following previous methodologies to minimize environmental contamination of the sample; a veterinarian identified the possible animal species as: 7 avian (3 waterfowl, 4 pigeon) and 8 dog/possibly fox. Kinyoun's acid-fast staining technique was used to determine the presence of coccidian oocysts and normal trichrome for the detection of Giardia spp. and Entamoeba spp. Thirty smears carefully monitored did not revealed any positive samples for these opportunistic parasites. These results might highlight a small circulation for the opportunistic parasites monitored, specifically for Cryptosporidium spp. and Giardia spp. However, our results should be considered preliminary and inconclusive, as molecular analysis of these samples and the collection of a more comprehensive number of faecal samples would be required to confirm the initial minor circulation (specifically for Cryptosporidium spp., Cyclospora spp. and Giardia spp.) and/or neglible presence (specifically for Entamoeba spp. and Cystoisospora spp.) for the opportunistic pathogens monitored. Therefore, further studies are needed to inform public regulators of potential risks to the population due to the presence/circulation of these pathogens in the Leicester’s urban media.