Emergence of a novel PRRSV-1 strain in mainland China: a recombinant
strain derived from the two commercial modified live viruses Amervac and
DV
Abstract
Porcine reproductive and respiratory syndrome virus 1 (PRRSV-1) is one
of the main pathogens causing porcine reproductive and respiratory
syndrome (PRRS). In recent years, the detection number of PRRSV-1 in
China has gradually increased, and the PRRSV-1 strains reported in China
belong to subtype Ⅰ (Global; Clade A-L). In the present study, a novel
PRRSV-1 strain, TZJ2134, was found during epidemiological surveillance
of PRRSV-1 in Shandong Province in China. We obtained two fragments of
TZJ2134: TZJ2134-L12 (located at nt 1672-nt 2112 in the partial Nsp2
gene) and TZJ2134-(A+B) (located at nt 7463-nt 11272 in the partial
Nsp9, complete Nsp10 and partial Nsp11 genes). Phylogenetic and
recombination analyses based on the two sequences showed that TZJ2134 is
a recombinant strain derived from two commercial PRRSV-1 modified live
vaccine (MLV) strains (the Amervac vaccine and DV vaccine strains),
forming a new recombinant subgroup of DV+Amervac-like isolates with
other strains. However, PRRSV-1 MLV is not currently allowed for use in
China. We speculated that TZJ2134 might have been introduced from
Europe. This study is the first to provide information on two
recombinant PRRSV-1 MLV strains in China and provides new data for the
epidemiological study of PRRSV-1 in China.