Metegenomic Investigation of Potential Pathogens and Zoonotic Risks Associated with Dog Feces in Seoul, South Korea

According to the World Health Organization (WHO), zoonoses are diseases or infections that can be naturally transmitted between animals and humans, as well as between humans and animals1. Domestic animals such as cattle, sheep, goats, dogs, cats, horses, and pigs can act as reservoirs of pathogens and transmit diseases to humans (Klous et al., 2016)2 and approximately 61% of human pathogens are zoonotic in nature (Taylor et al., 2001)3.Human population density has been identified as a significant predictor of emerging infectious diseases, including those caused by non-wildlife zoonotic pathogens (Jones et al., 2008)4. The increase in the population of stray and semi-domestic dogs in urban areas has also contributed to the risk of zoonotic diseases (Ghasemzadeh and Namazi, 2015)5. However, the role of companion animals, particularly dogs and cats, in the context of public health and zoonotic diseases is often overlooked (Overgaauw et al., 2020)6. In South Korea, a significant proportion of households own pets, with dogs being one of the most common companion animals (Kim and Chun)7. Studies have shown that public parks can be a source of zoonotic infections, particularly through the ingestion of contaminated soil, and stray dogs roaming in public areas can contribute to the transmission of zoonotic pathogens.Considering the high population density of Seoul10, the capital city of South Korea, and the potential for zoonotic emergence11, it is crucial to investigate the status of pathological processes associated with dogs in this area. However, there has been limited researches on potential pathogenic organisms and their composition in dog feces in Seoul. Therefore, this study aimed to utilize next-generation sequencing (NGS) to detect multiple potential pathogenic organisms and assess the current risk of zoonosis from the feces of dogs in Seoul. Although many bacterial microbiota analyses have been attempted using the feces of wild animals [16], only a few studies have used NGS to screen feces for parasites [17,18,19, 20]. Hence, we decided to use NGS to detect various kinds of pathogens including parasites. To the best of our knowledge, this is the first such study to be carried out in the research of dogs of Seoul, Republic of Korea.This study focused on analyzing fecal samples obtained from pet and stray dogs to identify potential pathogens and determine differences of prevalence between the two groups. In line with our research objectives, this study examined 41 dog fecal samples collected within Seoul, including 16 samples from pet dogs and 25 samples from stray dogs. By NGS screening, potential pathogens and their composition in different habitat environments were investigated. Additionally, we sought to compare the microbial composition and its association with pathogens between pet and stray dogs. The findings will provide valuable insights into the potential dangers and prevalence of pathogens associated with different living conditions of dogs, ultimately contributing to our understanding of zoonotic risks in the city.