Discovery of a Novel Species Infecting Goats: Morphological and Molecular Characterization of Babesia aktasi n. sp.

Abstract

A novel Babesia sp. infecting goats was discovered based on the molecular findings obtained in the current study, which was conducted in the Mediterranean region of Türkiye. The goal of this study was to isolate this species of Babesia (Babesia sp.) infecting goats in vivo and to assess the genetic and morphological characterization of the parasite. To identify the animal naturally infected with Babesia sp. and isolate the parasite from this animal, field studies were conducted first, and genomic DNA were extracted from blood samples taken from goats (n = 50). The Theileria, Babesia, and Anaplasma species were identified using a nested PCR-based reverse line blotting (RLB) method. The study included one goat that was determined to be infected with Babesia sp. (single infection) in RLB for in vivo isolation. A blood smear was prepared to examine the parasite’s morphology, but it was found to be negative microscopically. Following that, a splenectomy operation (to suppress the immune system) was performed to make the parasites visible microscopically in this animal. Parasitemia began after splenectomy, and the maximum parasitemia was determined to be 1.9%. The goat displayed no significant symptoms other than fever, loss of appetite, and depression. During a period when parasitemia was high, blood from this goat was inoculated into another splenectomized goat (Theileria-Babesia-Anaplasma-Mycoplasma spp. free). On the third day of inoculation, 10% parasitemia with high fever was detected in the goat, and on the fourth day, the goat was humanely euthanized due to severe acute babesiosis symptoms. Except for mild subcutaneous jaundice, no lesions were discovered during the necropsy. According to the microscopic measurement results, ring, double pyriform, spectacle-frame-like, and line forms were observed, and it was observed to be between 1.0–2.5 µm (1.38 ± 0.17 to 0.7 ± 0.21-all forms). A phylogenetic analysis and sequence comparison using the 18S rRNA and cox1 genes revealed that this species is distinct from the small ruminant Babesia species (18S rRNA 92–94%, cox1 79–80%) and has the highest similarity to Babesia sp. deer, which has been reported in deer. Furthermore, it was determined to resemble B. venatorum, B. divergens, Babesia sp. FR1 and Babesia sp. MO1 species, all of which are zoonotic. Additional research is needed to clarify the clinical status of this parasite in goats and other hosts (mountain goat, sheep, calf).

Babesia ovis secreted antigen-1 is a diagnostic marker during the active Babesia ovis infections in sheep

“…Xinjiang in China ( Yin et al., 1997 ; Bai et al., 2002 ) and Babesia aktasi n. sp. in Türkiye ( Ozubek et al., 2023 ; Ulucesme et al., 2023 ), which presented distinct morphologies from other ovine Babesia species in thin blood smears. Within these species, B. ovis is responsible for clinical infections and has a wider distribution than other species ( Uilenberg, 2006 ; Guan et al., 2009 ; Iqbal et al., 2011 ; Ozubek and Aktas, 2017 ; Ceylan et al., 2021b ).…”

Experimental infection of non-immunosuppressed and immunosuppressed goats reveals differential pathogenesis of Babesia aktasi n. sp.

“…Babesia aktasi n. sp., previously isolated from a naturally infected goat in the Mediterranean region of Turkiye, was utilized in this study (Ozubek et al, 2023). Briefly, one goat that was determined to be infected with B. aktasi n. sp.…”

“…After being isolated from a naturally infected goat and having its genetic and morphological traits characterized, this newly identified Babesia species was named Babesia aktasi n. sp. (Ozubek et al, 2023). Following that, a large-scale survey in the Mediterranean region revealed that B. aktasi n. sp.…”

“…Following inoculation, the second goat experienced a significant increase in body temperature and reached a parasitemia level of 10% on day three post-infection. Due to the severe acute symptoms of babesiosis, the goat was humanely euthanized four days post-infection (Ozubek et al, 2023). This previous study did not systematically investigate the pathogenicity of B. aktasi n.…”

Serological and Molecular Survey of Babesia ovis in Healthy Sheep in Türkiye

“…In the past 20 years, new species or genotypes of Babesia affecting sheep and goats have been identified, including Babesia sp. Xinjiang [3], Babesia aktasi [4], and Babesia motasi-like (B. motasi Lintan, B. motasi Tianzhu, B. motasi Hebei) [5]. Additionally, based on morphological, serological, pathogenic, genetic, and virulent characteristics, B. motasi has been further classified into two subgroups: B. motasi Lintanensis and B. motasi Hebeinensis [6,7].…”