Figure 1. PDCoV isolation in PK-15 cells and geographical map indicating locations where the outbreak was reported
Following PDCoV detection, intestinal content was filtered, and TPCK-trypsin treated for isolation in cell lines known to be permissible for PDCoV replication. Following 5 days of inoculation, no cytopathic effect (cpe) was evidenced under light microscopy in both cell lines. A second passage evidenced cpe after 24 h, with initial cell rounding and monolayer disruption in PK-15 cells but absent in Vero cells. Following 48 h of second passage, cpe was evidenced in almost 70 % of cell monolayer, characterized by cell rounding, cell detaching, pyknosis in PK-15 cell lines but no cytopathic effect was detected in Vero cell lines (A). Moreover, an immunofluorescence test with a PDCoV nucleoprotein monoclonal antibody confirmed viral replication in PK-15 infected cells (B). A representative map of South America (blue) highlighting Peru (orange) is shown in the upper right side. Additionally, a geographical map of San Martin department (yellow) located in the north of Peru (light green) is represented below (C).