Estimated quantity of swine virus genomes based on quantitative PCR analysis in spray-dried porcine plasma samples collected from multiple manufacturing plants

PLoS One. 2022 May 23;17(5):e0259613. doi: 10.1371/journal.pone.0259613. eCollection 2022.

Abstract

This survey was conducted to estimate the incidence and level of potential viral contamination in commercially collected porcine plasma. Samples of spray dried porcine plasma (SDPP) were collected over a 12- month period from eight spray drying facilities in Spain, England, Northern Ireland, Brazil, Canada, and the United States. In this survey, viral load for several porcine pathogens including SVA, TGEV, PRRSV (EU and US strains), PEDV, PCV-2, SIV, SDCoV and PPV were determined by qPCR. Regression of Ct on TCID50 of serial diluted stock solution of each virus allowed the estimate of potential viral level in SDPP and unprocessed liquid plasma (using typical solids content of commercially collected porcine plasma). In this survey SVA, TGEV or SDCoV were not detected in any of the SDPP samples. Brazil SDPP samples were free of PRRSV and PEDV. Samples of SDPP from North America primarily contained the PRRSV-US strain while the European samples contained the PRRSV-EU strain (except for one sample from each region containing a relatively low estimated level of the alternative PRRSV strain). Estimated viral level tended to be in the range from <1.0 log10 TCID50 to <2.5 log10 TCID50. Estimated level of SIV was the exception with a very low incidence rate but higher estimated viral load <3.9 log10 TCID50. In summary, the incidence of potential viral contamination in commercially collected porcine plasma was variable and estimated virus level in samples containing viral DNA/RNA was relatively low compared with that occurring at the peak viremia during an infection for all viruses or when considering the minimal infectious dose for each of them.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Feed / analysis
  • Animals
  • Genome, Viral
  • Manufacturing and Industrial Facilities
  • Plasma
  • Porcine Reproductive and Respiratory Syndrome*
  • Porcine respiratory and reproductive syndrome virus* / genetics
  • RNA, Viral
  • Real-Time Polymerase Chain Reaction
  • Swine
  • Viruses*

Substances

  • RNA, Viral

Grants and funding

Funding for this study was provided by APC Europe, S.L.U., Granollers, Spain, and APC LLC, Ankeny, IA, 50021, USA. These companies manufacture animal blood products for animal consumption. The funders provided support in the form of salaries for authors EB, CR, JC, LR and JPolo, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.