Genetic Evolution and Molecular Characterization of PRRSV GP5 in Germany

Porcine reproductive and respiratory syndrome (PRRS) has been prevalent in Germany for over 30 years, posing a significant threat to the local swine industry. There are limited analyses to offer German PRRSV ORF5 genetic and evolutionary characteristics and GP5 structural and functional features. In this study, a total of 518 sequences of the PRRSV GP5 gene were obtained from the GenBank database, encompassing 102 sequences from Germany to investigate the genetic relationships and GP5 structural and functional features. Similarly, phylogenetic and recombination analyses were used to identify genetic relationships. Two German PRRSV-1 lineage 1 strains exhibited more than 98.0% nucleotide similarity with vaccine strains. Eighteen German PRRSV-2 lineage 5 strains exhibited more than 98.0% nucleotide similarity with a prototype vaccine strain. German PRRSV-1 lineage 1 was predominant. GP5 structural and functional features were determined by N-glycosylation sites, B-cell epitopes, and transmembrane domain predictions. The main N-glycosylation patterns and transmembrane domains of German PRRSV-1 lineage 1 were time-dependent. Mutations of German PRRSV-1 lineage 3 in the primary neutralizing epitope were detected. In conclusion, these findings reveal lineage-specific molecular variation and improve the understanding of the molecular evolution of German PRRSV.