Blastocystis isolates from a dog and their owners presenting with chronic diarrhoea. Dogs as reservoirs of Blastocystis: research in Poland and worldwide

Molecular Detection and Genetic Diversity of Blastocystis in Korean Dogs

Blastocystis is a genus of unicellular heterokont parasites belonging to a group of organisms known as Stramenopiles, which includes algae, diatoms, and water molds. Blastocystis includes several species that habitat in the gastrointestinal tracts of organisms as diverse as humans, farm animals, birds, rodents, reptiles, amphibians, fish, and cockroaches. It is important to public health and distributed globally, but its prevalence in dogs in Korea has not been reported to date. Here, we collected 787 canine fecal samples and assessed Blastocystis infection by age, sex, region, season, and diarrhea symptoms. We determined Blastocystis subtypes using phylogenetic analyses based on 18S rRNA gene sequences. We identified, 10 Blastocystis positive samples (1.3%). A higher proportion of infected dogs was asymptomatic; however, infection rates did not significantly differ according to region, age, sex, and season. Phylogenetic analysis showed that the Blastocystis sp. identified belonged to 4 subtypes (STs), ST1, ST5, ST10, and ST14, thus revealed the genetic diversity of Blastocystis sp. in dogs Korean. This is first report on the presence of Blastocystis sp. in dogs Korean. This study revealed a lower infection rate than expected and differed from previous studies in STs. Further studies are warranted to observe the national infection status of Blastocystis in dogs and the genetic characteristics of this genus.

Rare Occurrence of Blastocystis in Pet Animals and Their Owners in the Pomeranian Voivodeship in Poland in the Light of Literature Data

Blastocystis is an intestinal microeukaryote with ambiguous pathogenicity, commonly detected in human feces worldwide. It comprises at least 28 genetically diverse subtypes (STs), 12 of which also occur in a wide range of animal species, giving rise to suspicion of zoonotic transmission. To investigate this, we conducted a molecular study of 145 stool samples of pet animals, and 67 of their owners, living in an urban area in Poland. Blastocystis was detected in only three (2.1%) animal samples (of two bearded agamas and a leopard gecko), while all dogs, cats, and pet rodents were Blastocystis-negative. Blastocystis was also present in three (4.5%) owners of animals, but they were cat owners, not reptile owners, and the subtypes identified in them differed significantly from those of reptiles. Additionally, the frequency of Blastocystis in different groups of dogs (depending on how they were kept) was analyzed. This work is the first to find Blastocystis in pet reptiles, and we encourage further investigation of Blastocystis in this poorly examined group of animals, as well as continued study on the transmission of this microorganism between humans and animals.

Blastocystis occurrence and subtype diversity in wild European terrestrial mammals - The case of Białowieża Primeval Forest (NE Poland)

Blastocystis cf. Blastocystis hominis is the most common unicellular parasite found in human and animal intestines. Little is known about the life cycle, transmission and mechanisms of pathogenesis for this parasite. The aim of this study was to obtain new data on the genetic diversity of Blastocystis in selected species of mammals found in the Białowieża Primeval Forest (BPF), Poland, the best preserved lowland forest in temperate Europe. 113 faecal samples were collected in the period 2018–2020 from seven species of wild mammals occurring within the Polish part of BPF and its surroundings. Blastocystis was detected by molecular amplification and sequencing the small subunit rRNA gene. The overall prevalence of Blastocystis in animals was 8.9%. A larger number of stool samples (90) were collected from European bison and only for this species was it possible to calculate the prevalence of infection (5.6%). The isolates obtained from European bison were classified as ST1, ST3, ST5, ST7. Blastocystis was also detected in the grey wolf (Canis lupus) (ST5), wild boar (Sus scrofa) (ST5) and red deer (Cervus elaphus) (ST1). In conclusion, for the first time we have demonstrated the presence of Blastocystis in wild European bison. Preliminary studies have shown that Blastocystis is present in at least 4 species of wild mammals in the BPF area and that it exhibits great genetic diversity.

Blastocystis is present in wild mammals in the Białowieża Primeval Forest

Blastocystis in the Białowieża Primeval Forest exhibits great genetic diversity

Intra-species and interspecific transmission of Blastocystis in Białowieża Primeval Forest is highly probable.