Isolation of thermotolerant Vermamoeba vermiformis strains from water sources in Lanzarote Island, Canary Islands, Spain.

In this study, twenty water samples were collected in the island of Lanzarote, Canary Islands, Spain in order to check for the presence of V. vermiformis strains in these samples. Water samples were cultured on 2% Non-Nutrient Agar (NNA) plates covered with a thin layer of heat killed E. coli and checked daily for the presence of Vermamoeba. After a week, V. vermiformis amoebae were observed in 2 of the 20 processed samples (10%) incubated at room temperature and 37°C. Molecular characterization was carried out by amplifying the 18S rDNA gene and DNA sequencing in order to confirm the identity of the isolated amoebic strains. To the best of our knowledge, this is the first report on the presence of FLA in environmental sources in Lanzarote Island and the first report of Vermamoeba vermiformis in water sources in this island. Furthermore, the two strains isolated in this study were collected in recreational areas with close contact with humans and thus awareness should be raised.

Isolation and Molecular Identification of Vermamoeba vermiformis Strains from Soil Sources in El Hierro Island, 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. Furthermore, some genera/species of FLA such as Naegleria fowleri, Balamuthia mandrillaris and Acanthamoeba spp. are also able to cause opportunistic infections in humans and other animals. More recently, FLA have been reported to be environmental carriers of pathogenic bacteria, fungi and viruses, and thus have gained further importance from the public health point of view. Among them, Acanthamoeba spp. and Vermamoeba vermiformis have been described in many occasions as the most common carriers of pathogens of high medical relevance such as Legionella pneumophila and Mycobacterium spp. In this study, 24 soil samples were collected from the island of El Hierro, Canary Islands, Spain, in order to check for the presence of V. vermiformis strains in these samples. Soil samples were cultured on 2 % non-nutrient agar plates covered with a thin layer of heat-killed E. coli and checked daily for the presence of Vermamoeba. After a week, V. vermiformis amoebae were observed in 5 of the 24 processed samples (20.8 %) incubated at room temperature and 37 °C. Molecular characterization was carried out by amplifying the 18S rDNA gene and DNA sequencing, confirming that the isolated strains belonged to Vermamoeba vermiformis species. The high percentage of V. vermiformis in the studied soil sources should raise awareness in the region since these amoebae are potential environmental carriers of pathogens of high medical relevance.

Acanthamoeba genotypes T2, T4, and T11 in soil sources from El Hierro island, Canary Islands, Spain.

The genus Acanthamoeba includes pathogenic strains which are causative agents of keratitis and encephalitis that often may end fatal in humans and other animals. In the present study, forty soil samples were collected in the island of El Hierro, Canary Islands, Spain, and checked for the presence of Acanthamoeba. Samples were cultivated onto 2 % non-nutrient agar plates seeded with a layer of heat killed Escherichia coli. Amplification by PCR and sequencing of the DF3 region of the 18S rDNA of Acanthamoeba was carried out in order to confirm morphological identification of the amoebae. Furthermore, Acanthamoeba spp. was isolated from 47.5 % of soil samples. Moreover, genotypes T2, T4, and T11 were identified in these samples. To the best of our knowledge, this is the first study to establish genotypes T2, T4, and T11 in soil sources from El Hierro island.