Detection PCV2a, PCV2b, PCV3 and PCV4 load in pooled tissues from mummified fetuses and stillbirths from a pig herd with reproductive disorders

• Grant number: 22/12349-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2022
• End date: August 31, 2023
• Field of knowledge: Agronomical Sciences - Veterinary Medicine
• Principal Investigator: Alessandra Marnie Martins Gomes de Castro
• Grantee: Rosecleer Rodrigues da Silva
• Host Institution: Faculdade ANCLIVEPA. Associação Nacional de Clínicos Veterinários de Pequenos Animais (ANCLIVEPA-SP). São Paulo , SP, Brazil

Abstract

The growth and intensification of swine production observed in the last four decades led to the emergence and reemergence of swine viruses. Among the main viral agents, the Porcine circovirus (PCV) stand out. Currently, 4 circovirus species are described (PCV1, PCV2, PCV3 and PCV4). Among the problems generated by these viruses, reproductive failures are of great importance due to the enormous damage caused as a result of increased sow mortality, decreased conception rates, miscarriages, mummified and/or stillborn fetuses, weak born piglets, infertility and embryonic death. With the exception of PCV1, which is not pathogenic for swine, and PCV4, discovered in 2019 and reported only in China and Korea so far, the other pathogens have a wide geographic distribution and are of worldwide concern. PCV2 has a high mutation rate and, currently, eight genotypes (PCV2a - PCV2h) are described, with PCV2a and PCV2b being the most prevalent worldwide. PCV3, discovered in 2015, has been mainly associated with reproductive disorders, being detected in pools of mummified and stillborn tissues. Based on this, the present study aims to: (i) standardize a PCV4 detection system by quantitative PCR (qPCR); (ii) detect and quantify the presence of PCV2a, PCV2b, PCV3, PCV4 viral DNA. Samples of mummified and stillborn fetuses (organ pool) from 86 females with 0 (gilts) to 11 births from a farm with reproductive disorders will be analyzed. This study will provide information on the presence of PCV4 in Brazilian herds, the impact of co-infections and the standardization of a diagnostic tool for PCV4.