ADAPTATION AND ANALYSIS OF PORCINE CIRCOVIRUS 2 IN PORCINE KIDNEY (PK-15) CELLS CULTURED WITH LOW SERUM SUPPLEMENTATION

This study aimed to cultivate PK-15 cells under serum-deprived conditions and subsequently adapt a field-isolated PCV2b genotype in these adapted cells to investigate both cellular and viral changes. PK-15 cells were grown in three different serum-supplemented media: 0%, 2%, and 10%. The cells adapted to these varying serum conditions were then infected with genotyped field PCV2b and propagated for up to three blind passages. Haematoxylin and eosin (H&E) staining of PK-15 cells grown in 0% and 2% serum-supplemented media, with and without PCV2b infection, revealed cytoplasmic granularity compared to cells grown in 10% serum. MTT assay results indicated that PCV2b infection had minimal impact on cell viability, suggesting efficient viral propagation in serum-deprived conditions with minimal cytopathic effects. PCR analysis of cell lysates from all three 0%, 2%, and 10% serum conditions confirmed the presence of the PCV2b genome, demonstrating its adaptability grown to PK-15 cells under serum-deprived conditions. Molecular analysis of the major epidemiological marker gene, ORF2, from PCV2b grown in both 0% and 10% serum conditions showed identical nucleotide (702 bp) and amino acid (234 aa) compositions. This study highlights the feasibility of growing PK-15 cells under serum-deprived conditions and the adaptability of PCV2b in these cells.