A group of researchers from the University of Cologne have found in amoebas previously undescribed bacteria that are associated with Legionella and can cause disease. The researchers dubbed one of the newly discovered bacteria “Pokémon” because they live in spherical amoebas, comparable to video game Pokémon that are trapped in balls.
The bacteria of the order Legionellales have long been of scientific interest, as some of them are known to cause lung disease in humans and animals. For example, Legionnaires’ disease, which is caused by Legionella pneumophila species, can sometimes be fatal. Legionellales bacteria live and multiply as intracellular parasites in the cells of host organisms. In particular, the hosts of Legionellales are amoeba. The term “amoeba” is used to describe a variety of microorganisms that are not closely related, but have different shapes and move using pseudopods.
“We wanted to test the amoebae for Legionellales and selected a group of these creatures for our study that had no close relationship with the previously studied hosts. The choice fell on the Thecofilosea group of amoebas, which is often overlooked by researchers.”
Marcel Dominique Solbach
Indeed, the spherical Thecofilosea serve as hosts for the Legionellales. In the amoeba Thecofilosea from environmental samples, scientists were able to detect various species of Legionellales, including two previously undescribed genera and one undescribed species from the genus Legionella.
The researchers named one of the bacterial genera they discovered “Pokemon.” The genus name Pokemonas is a play on words based on the Pokémon video game franchise, which celebrates its 25th anniversary this year and which should be familiar to most school children, students and their parents. The name alludes to the intracellular way of life of their bacteria in the globular amoeba Thecofilosea, because in this game, little monsters are caught in the balls, much like the Pokemonas in Thecofilosea.
“The results show that the range of known hosts for these bacteria is much wider than previously thought. In addition, these results suggest that many more amoebas may host Legionellales and are therefore potentially disease carriers. To further explore this issue, we are now sequencing the full genome of these bacteria.”
Kenneth Dumak, Study Director
In the future, these new discoveries should help us understand how Legionellales bacteria relate to each other and clarify their interactions with hosts and transmission routes to prevent disease outbreaks in humans.