Stenamoeba dejonckheerei sp. nov., a Free-Living Amoeba Isolated from a Thermal Spring.

Manuel Alejandro Borquez-Román,José Cuauhtémoc Ibarra-Gámez,Libia Zulema Rodriguez-Anaya,Fernando Lares-Villa,Jose Reyes Gonzalez-Galaviz,Luis Fernando Lares-Jiménez,Ramón Casillas-Hernández,Paul A Fuerst

doi:10.3390/pathogens9070586

Manuel Alejandro Borquez-Román, José Cuauhtémoc Ibarra-Gámez + Show 6 more

Open Access

https://doi.org/10.3390/pathogens9070586

Copy DOI

Abstract

Two amoeboid organisms were obtained from water samples taken from a thermal spring, "Agua Caliente", in Northwestern Mexico. The isolates were obtained when samples were cultivated at 37 °C on non-nutrient agar coated with Escherichia coli. The initial identification of the isolates was performed morphologically using light microscopy. The samples were found to have trophozoite morphology consistent with members of the genus Stenamoeba, a genus derived in 2007 from within the abolished polyphyletic genus Platyamoeba. Further analysis was performed by sequencing PCR products obtained using universal eukaryotic primers for the small subunit ribosomal ribonucleic acid (SSU rRNA) gene. Sequencing primers were designed to allow the comparison of the 18S rRNA gene sequences of the new isolates with previous sequences reported for Stenamoeba. Phylogenetic relationships among sequences from Stenamoeba were determined using Maximum Likelihood analysis. The results showed the two "Agua Caliente" sequences to be closely related, while clearly separating them from those of other Stenamoeba taxa. The degrees of sequence differentiation from other taxa were considered sufficient to allow us to propose that the Mexican isolates represent a new species.

Highlights

Studies were conducted in February 2017 to identify the occurrence of potentially pathogenic free-living amoebae within a natural hot spring—two isolates, in particular, received our attention.These isolates were morphologically identified as potential members of the genus Stenamoeba [1,2].Further analysis, detailed here, has revealed that these isolates represent a new member of Stenamoeba, genetically differentiated from any previously reported form
We show that the two amoebae isolates from the “Agua Caliente” hot springs are closely related, and that they represent a novel, previously undescribed species within Stenamoeba, well-differentiated genetically from previously defined taxa, and which we propose to represent as Stenamoeba dejonckheerei sp. nov
Differences in the growth rate and appearance when strains M32 and M33 were grown in non-nutritive agar plates added with Escherichia coli (NNE), at 37 ◦ C were observed

Summary

Introduction

Studies were conducted in February 2017 to identify the occurrence of potentially pathogenic free-living amoebae within a natural hot spring—two isolates, in particular, received our attention.These isolates were morphologically identified as potential members of the genus Stenamoeba [1,2].Further analysis, detailed here, has revealed that these isolates represent a new member of Stenamoeba, genetically differentiated from any previously reported form. Studies were conducted in February 2017 to identify the occurrence of potentially pathogenic free-living amoebae within a natural hot spring—two isolates, in particular, received our attention. These isolates were morphologically identified as potential members of the genus Stenamoeba [1,2]. The genus Stenamoeba was originally defined in 2007 [3], where it was shown that the taxa previously denoted Platyamoeba stenopodia, Page 1969, was not correctly placed within the Vanellida, but was a member of the Thecamoebida [3,4]. The new genus till considered monospecific (Stenamoeba stenopodia), soon expanded with the identification of a number of new species [3,5,6,7].

Methods

Results

Discussion

Conclusion