First detection and genetic characterization of a novel kirkovirus from a dead thoroughbred mare in northern Xinjiang, China, in 2018.

This research focuses on the identification and genomic characterization of a new kirkovirus strain, named Cj-7-7, from a deceased thoroughbred mare in China, providing insights into its genetic diversity, geographical distribution, and prevalence.

Identification of Pathogen

• The research was conducted after the death of an 8-year-old thoroughbred mare at an equestrian club in Changji, Xinjiang, China in May 2018. The horse, imported from the United States in 2013, had foaled but gradually lost weight post-foaling, leading to its death.
• The aim of the study was to identify the pathogen responsible for the horse’s death via a virome analysis. A virome is the total collection of viruses in and on an organism.
• The analysis led to the identification of an ‘Equ1-like’ virus in the horse’s fecal virome, suggesting a potential pathogen role in the horse’s demise.

Genetic Characterization of the Virus

• The newly identified virus underwent full genomic sequencing and phylogenetic analysis for classification and understanding its genetic characteristics.
• The virus, tentatively named ‘kirkovirus Cj-7-7’, is closely related to the already known kirkovirus Equ1, suggesting a similar genetic makeup and potential disease-causing capability.
• Kirkovirus Cj-7-7 clusters together with po-circo-like viruses 21, 22, 41, and 51, further suggesting its possible assignment to the proposed family ‘Kirkoviridae’.

Epidemiological and Geographical Implications

• An epidemiological investigation indicated that kirkovirus Cj-7-7 circulates in the horse population of northern Xinjiang, hence, indicating the specific existence and prevalence of this virus in this geographical location.
• Additionally, the evidence implies that the virus might specifically infect the intestinal cells of horses, potentially causing detrimental health effects.

Significance of Findings

• The research findings provide a critical understanding of the genetic diversity and geographical distribution of Kirkoviruses, adding to existing knowledge in the field.
• Detection of the new Kirkovirus strain, Cj-7-7, particularly in the Xinjiang region of China, aids epidemiological data, contributing to horse health management strategies in the area.