TY - JOUR
T1 - Evolutionary diversification of type 2 porcine reproductive and respiratory syndrome virus
AU - Brar, Manreetpal Singh
AU - Shi, Mang
AU - Murtaugh, Michael P.
AU - Leung, Frederick Chi Ching
N1 - Publisher Copyright:
© 2015 The Authors.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the leading swine pathogens causing tremendous economic loss to the global swine industry due to its virulence, pathogenesis, infectivity and transmissibility. Although formally recognized only two and half decades ago, molecular dating estimation indicates a more ancient evolutionary history, which involved divergence into two genotypes (type 1 and type 2) prior to the ‘initial’ outbreaks of the late 1980s. Type 2 PRRSV circulates primarily in North America and Asia. The relatively greater availability of sequence data for this genotype from widespread geographical territories has enabled a better understanding of the evolving genotype. However, there are a number of challenges in terms of the vastness of data available and what this indicates in the context of viral diversity. Accordingly, here we revisit the mechanisms by which PRRSV generates variability, describe a means of organizing type 2 diversity captured in voluminous ORF5 sequences in a phylogenetic framework and provide a holistic view of known global type 2 diversity in the same setting. The consequences of the expanding diversity for control measures such as vaccination are discussed, as well as the contribution of modified live vaccines to the circulation of field isolates. We end by highlighting some limitations of current molecular epidemiology studies in relation to inferring PRRSV diversity, and what steps can be taken to overcome these and additionally enable PRRSV sequence data to be informative about viral phenotypic traits such as virulence.
AB - Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the leading swine pathogens causing tremendous economic loss to the global swine industry due to its virulence, pathogenesis, infectivity and transmissibility. Although formally recognized only two and half decades ago, molecular dating estimation indicates a more ancient evolutionary history, which involved divergence into two genotypes (type 1 and type 2) prior to the ‘initial’ outbreaks of the late 1980s. Type 2 PRRSV circulates primarily in North America and Asia. The relatively greater availability of sequence data for this genotype from widespread geographical territories has enabled a better understanding of the evolving genotype. However, there are a number of challenges in terms of the vastness of data available and what this indicates in the context of viral diversity. Accordingly, here we revisit the mechanisms by which PRRSV generates variability, describe a means of organizing type 2 diversity captured in voluminous ORF5 sequences in a phylogenetic framework and provide a holistic view of known global type 2 diversity in the same setting. The consequences of the expanding diversity for control measures such as vaccination are discussed, as well as the contribution of modified live vaccines to the circulation of field isolates. We end by highlighting some limitations of current molecular epidemiology studies in relation to inferring PRRSV diversity, and what steps can be taken to overcome these and additionally enable PRRSV sequence data to be informative about viral phenotypic traits such as virulence.
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U2 - 10.1099/vir.0.000104
DO - 10.1099/vir.0.000104
M3 - Review article
C2 - 25711962
AN - SCOPUS:84938306386
SN - 0022-1317
VL - 96
SP - 1570
EP - 1580
JO - Journal of General Virology
JF - Journal of General Virology
IS - 7
ER -