Investigation of potential pathogenicity of Willaertia magna by investigating the transfer of bacteria pathogenicity genes into its genome

Abstract

Willaertia magna c2c maky is a thermophilic amoeba closely related to the genus Naegleria. This free-living amoeba has the ability to eliminate Legionella pneumophila, which is an amoeba-resisting bacterium living in an aquatic environment. To prevent the proliferation of L. pneumophila in cooling towers, the use of W. magna as natural biocide has been proposed. To provide a better understanding of the W. magna genome, whole-genome sequencing was performed through the study of virulence factors and lateral gene transfers. This amoeba harbors a genome of 36.5 megabases with 18,519 predicted genes. BLASTp analyses reported protein homology between 136 W. magna sequences and amoeba-resistant microorganisms. Horizontal gene transfers were observed based on the basis of the phylogenetic reconstruction hypothesis. We detected 15 homologs of N. fowleri genes related to virulence, although these latter were also found in the genome of N. gruberi, which is a non-pathogenic amoeba. Furthermore, the cytotoxicity test performed on human cells supports the hypothesis that the strain c2c maky is a non-pathogenic amoeba. This work explores the genomic repertory for the first draft genome of genus Willaertia and provides genomic data for further comparative studies on virulence of related pathogenic amoeba, N. fowleri.

Intracellular Behaviour of Three Legionella pneumophila Strains within Three Amoeba Strains, Including Willaertia magna C2c Maky

“…To conclude, W. magna C2c Maky is not associated with any human or animal infection, and this is in agreement with the lack of pathogenicity demonstrated in vivo and suggested by genomic analysis [24,48]. This organism is likely a safe and efficient candidate for legionella control in cooling towers and could provide an alternative solution to chemical biocides.…”

“…The living forms of this amoeba include a large trophozoite (50-100 µm) and a cyst (18-21 µm) form, and it can produce temporary flagella [22,23]. The lack of pathogenicity of this amoeba was demonstrated by cytotoxicity testing on human cells and was confirmed by genomic analysis [24]. According to these findings, the Amoéba company developed a natural biocide using W. magna C2c Maky to eliminate L. pneumophila as an alternative to chemical biocides (http://www.amoeba-biocide.com/en/page/revolutionary-biocide).…”

Description of Virulent Factors and Horizontal Gene Transfers of Keratitis-Associated Amoeba Acanthamoeba Triangularis by Genome Analysis

“…Out of 99 putative genes exchanged with ARMs, 49 genes were virus-infecting amoebas. The proportion of giant viral sequences within A. triangularis (0.13%) was smaller compared to A. castellani Neff (1.2%) and W. magna c2c maky (0.3%) [33,42]. However, the proportion was higher compared to the giant virus sequences contained in the genome of A. polyphaga (0.1%) [21].…”

A New Active Substance Derived from Lyzed Willaertia magna C2c Maky Cells to Fight Grapevine Downy Mildew

“…W. magna C2c Maky, a thermophilic free-living amoebae (FLA) belonging at the Vahlkampfiidae family [ 10 ], was isolated from the water of a thermal swimming pool in 1988. The lack of pathogenicity of this amoeba was demonstrated by culture and confirmed by omic analyses [ 11 , 12 ]. FLA are ubiquitous protozoa that inhabit common aquatic environments [ 13 , 14 ].…”