Tissue tropisms opt for transmissible reassortants during avian and swine influenza A virus co-infection in swine

Authors

Xiaojian Zhang, Mississippi State University
Hailiang Sun, Mississippi State University
Fred L. Cunningham, USDA APHIS Wildlife Services NWRCFollow
Lei Li, Mississippi State University
Katie Hanson-Dorr, USDA APHIS Wildlife Services NWRC
Matthew W. Hopken, USDA APHIS Wildlife Services NWRC
Jim Cooley, Mississippi State University
Li-Ping Long, Mississippi State University
John A. Baroch, USDA APHIS Wildlife Services NWRC
Tao Li, Walter Reed Army Institute of Research
Brandon S. Schmit, USDA APHIS Wildlife Services NWRC
Xiaoxu Lin, Walter Reed Army Institute of Research
Alicia K. Olivier, Mississippi State University
Richard G. Jarman, Walter Reed Army Institute of Research
Thomas J. DeLiberto, USDA APHIS Wildlife Services NWRCFollow
Xiu-Feng Wan, Mississippi State UniversityFollow

Document Type

Article

Date of this Version

2018

Citation

PLoS Pathog 14(12): e1007417

Comments

Open access

https://doi.org/10.1371/journal.ppat.1007417

Abstract

Genetic reassortment between influenza A viruses (IAVs) facilitate emergence of pandemic strains, and swine are proposed as a “mixing vessel” for generating reassortants of avian and mammalian IAVs that could be of risk to mammals, including humans. However, how a transmissible reassortant emerges in swine are not well understood. Genomic analyses of 571 isolates recovered from nasal wash samples and respiratory tract tissues of a group of co-housed pigs (influenza-seronegative, avian H1N1 IAV–infected, and swine H3N2 IAV– infected pigs) identified 30 distinct genotypes of reassortants. Viruses recovered from lower respiratory tract tissues had the largest genomic diversity, and those recovered from turbinates and nasal wash fluids had the least. Reassortants from lower respiratory tracts had the largest variations in growth kinetics in respiratory tract epithelial cells, and the cold temperature in swine nasal cells seemed to select the type of reassortant viruses shed by the pigs. One reassortant in nasal wash samples was consistently identified in upper, middle, and lower respiratory tract tissues, and it was confirmed to be transmitted efficiently between pigs. Study findings suggest that, during mixed infections of avian and swine IAVs, genetic reassortments are likely to occur in the lower respiratory track, and tissue tropism is an important factor selecting for a transmissible reassortant.