Swine viral detection by adapted Next-Generation Sequencing (NGS) for RNA and DNA species reveals first detection of porcine circovirus type 3 (PCV3) in Chile

The outbreak and propagation of COVID-19 have posed a significant challenge to our society, highlighting the relevance of epidemiological monitoring of animal pathogens closely related to humans due to potential zoonosis. To find previously undetected viruses inside Chilean swine farms, we collected non-invasive samples from animals suspected to undergo any viral disease. After screening by Next Generation Sequencing (NGS) adapted to identify viral species with RNA and DNA genomes simultaneously, different viral species were successfully detected. Among viruses with an RNA genome, Porcine Rotavirus A (RVA), Porcine Astrovirus type 5 (PAstV-5) and Porcine Feces-Associated IASV-like virus (PfaIV) were identified; whereas among viruses with DNA genome, Porcine Parvovirus 1 (PPV1), Porcine Circovirus type 1 (PCV1) and Porcine Circovirus type 3 (PCV3) were found. PCV3, a recently described pathogenic virus, was detected for the first time in Chile in different samples from mummified tissue of stillbirths. The whole genome sequence of PCV3 was completed using conventional PCR and Sanger sequencing and compared with previously reported genomes. To the best of our knowledge, this is the first time that an adapted NGS system is used for the screening of DNA and RNA viral species simultaneously inside the Chilean swine industry. This adapted NGS system might be useful for the detection of swine viral emerging diseases worldwide.