Identification and molecular characterization of four new Blastocystis subtypes designated ST35-ST38

Authors: Maloney, Jenny; Molokin, Aleksey; SEGUÍ, RAIMUNDO - Valencia University; MARAVILLA, PABLO - The General Hospital Dr Manuel Gea González; MARTÍNEZ-HERNÁNDEZ, FERNANDO - The General Hospital Dr Manuel Gea González; VILLALOBOS, GUIEHDANI - The General Hospital Dr Manuel Gea González; TSAOUSIS, ANASTASIO - University Of Kent; GENTEKAKI, ELENI - Mae Fah Luan University; CARMENA, DAVID - National Center For Microbiology, The Institute Of Health Carlos Iii; Santin-Duran, Monica; MUÑOZ-ANTOLIÍ, CARLA - Valencia University; KLISIOWICZ, DEBORA - Universidade Federal Do Parana; OISHI, CAMILA - Universidade Federal Do Parana; TOLEDO, RAFAEL - Valencia University

Submitted to: Microorganisms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2023
Publication Date: 12/23/2023
Citation: Maloney, J.G., Molokin, A., Seguí, R., Maravilla, P., Martínez-Hernández, F., Villalobos, G., Tsaousis, A.D., Gentekaki, E., Carmena, D., Santin, M., Muñoz-Antolií, C., Klisiowicz, D.R., Oishi, C.Y., Toledo, R. 2023. Identification and molecular characterization of four new Blastocystis subtypes designated ST35-ST38. Microorganisms. 11:43. https://doi.org/10.3390/microorganisms11010046.
DOI: https://doi.org/10.3390/microorganisms11010046

Interpretive Summary: Four novel sequences of Blastocystis were recently identified in three different studies of Blastocystis epidemiology in mammalian hosts. These sequences were not promoted to new Blastocystis subtypes for two reasons. First, the full-length reference sequences needed to confirm their status as new subtypes were not available. Second, the sequences were all unusual in that they appeared more similar to an isolate from a sea snake than to any available mammalian or avian sequences. The present study used a long read sequencing strategy to obtain the full-length reference sequences needed to name these isolates as new subtypes of Blastocystis. Phylogenetic analyses and pairwise distance comparisons were also performed to confirm the validity of each of these new subtypes. Based on the data collected in this study we propose the novel sequences be assigned the subtype designations ST35-ST38. Full-length reference sequences of ST35-ST38 can now be used to assist in the study of Blastocystis epidemiology and subtype diversity. This information should be useful to other scientists and public health agencies working on Blastocystis to better understand the relationships between the genetic complexity of Blastocystis and its host specificity, pathogenicity, and epidemiology.

Technical Abstract: Three recent studies of Blastocystis epidemiology in mammalian hosts identified four novel sequences which appeared to share B. lapemi as the most similar sequence. However, full-length ssu rRNA gene sequences were not available to confirm the validity of these new subtypes. In the present study, Nanopore MinION sequencing was used to obtain full-length reference sequences for each of the new subtypes. Additionally, phylogenetic analyses and pairwise distance comparisons were performed to confirm the validity of each of these new subtypes. We propose the novel sequences described in this study be assigned the subtype designations ST35-ST38. The full-length reference sequences of ST35-ST38 will assist in accurate sequence descriptions in future studies of Blastocystis epidemiology and subtype diversity.