Molecular detection and characterization of Blastocystis in herbivore livestock species in Portugal

Authors: FIGUEIREDO, ANA - University Of Aveiro (UA); Santin-Duran, Monica; KÖSTER, PAMELA - National Center For Microbiology, The Institute Of Health Carlos Iii; DAHSTI, ALEJANDRO - National Center For Microbiology, The Institute Of Health Carlos Iii; Maloney, Jenny; TORRES, RITA - University Of Aveiro (UA); FONSECA, CARLOS - University Of Aveiro (UA); MYSTERUD, ATLE - University Of Oslo; CARVALHO, JOAO - University Of Aveiro (UA); HIPÓLITO, DARÍO - University Of Aveiro (UA); ROSSA, MARIANA - University Of Aveiro (UA); PALMEIRA, JOSMAN - University Of Aveiro (UA); GONZÁLEZ-BARRIO, DAVID - National Center For Microbiology, The Institute Of Health Carlos Iii

Submitted to: International Journal for Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2024
Publication Date: 3/5/2024
Citation: Figueiredo, A.M., Santin, M., Köster, P.C., Dahsti, A., Maloney, J.G., Torres, R.T., Fonseca, C., Mysterud, A., Carvalho, J., Hipólito, D., Rossa, M., Palmeira, J.D., González-Barrio, D. 2024. Molecular detection and characterization of Blastocystis in herbivore livestock species in Portugal. International Journal for Parasitology. 327: Article e110147. https://doi.org/10.1016/j.vetpar.2024.110147.
DOI: https://doi.org/10.1016/j.vetpar.2024.110147

Interpretive Summary: Blastocystis is a common intestinal protist in humans and animals worldwide, with a high level of genetic diversity. Data on the prevalence and subtypes of Blastocystis in livestock in Portugal is limited. Therefore, we have conducted the most comprehensive study of Blastocystis in herbivore livestock species ever performed through PCR and next generation sequencing in Portugal. A total of 180 fecal samples from herbivore livestock (cattle, goats, horses, and sheep) in different regions of the country were tested with Blastocystis present in 40.6% (73/180) of the samples (goats, 81.0%; sheep, 60.9%; cattle, 32.2%). None of the horse samples were Blastocystis-positive. Eighteen subtypes were detected (ST1, ST2, ST3, ST5, ST6, ST7, ST10, ST13, ST14, ST21, ST23, ST24, ST25, ST26, ST30, ST42, ST43, and ST44). Mixed infections were common as well as presence of subtypes previously reported in humans. Our data provide novel molecular evidence strongly suggesting that some Blastocystis subtypes and subgroups may have differential host specificity. This information will be useful to other scientists, veterinarians, and public health agencies to better understand transmission, zoonotic potential, and public health importance of Blastocystis.

Technical Abstract: Blastocystis is a ubiquitous intestinal protist in humans and animals worldwide. The traditional livestock free-roaming raising system in rural communities increases the risk of infection with contact with a wider range of pathogens transmitted via the faecal-oral route associated with that wildlife-livestock-human interface. However, no studies have been conducted to determine the occurrence and subtype distribution of Blastocystis in livestock in Portugal. Here, we collected 180 faecal samples from herbivore livestock (cattle, goats, horses, and sheep) in different regions of the country to investigate Blastocystis prevalence and subtype diversity using PCR and next generation amplicon sequencing. Blastocystis was present in 40.6% (73/180; 95% CI: 33.31–48.11) of the samples (goats, 81.0%; sheep, 60.9%; cattle, 32.2%). None of the horse samples were Blastocystis-positive. Eighteen subtypes were detected (ST1, ST2, ST3, ST5, ST6, ST7, ST10, ST13, ST14, ST21, ST23, ST24, ST25, ST26, ST30, ST42, ST43, and ST44). Mixed infections were detected in 97.3% of the Blastocystis-positive samples. Potentially zoonotic subtypes were identified in 75.0%, 96.4%, and 100% of the Blastocystis-positive specimens collected from cattle, sheep, and goats, respectively. These results demonstrate that cattle, sheep, and goats harbour a high diversity of Blastocystis subtypes in the study regions. Importantly, our data provide novel molecular evidence strongly suggesting that some Blastocystis STs/ST subgroups may have differential host specificity.