The role of virulence for in vivo superinfection fitness of a vertebrate RNA virus

Journal of Virology
By: , and 



We have developed a novel, in vivo superinfection fitness assay to examine superinfection dynamics and the role of virulence in superinfection fitness. This assay involves controlled, sequential infections of a natural, vertebrate host, Oncorhynchus mykiss (rainbow trout), with variants of a co-evolved viral pathogen, infectious hematopoietic necrosis virus (IHNV). Intervals between infections ranged from 12 hours to 7 days, and both frequency of superinfection and viral replication levels were examined. Using virus genotype pairs of equal and unequal virulence, we observed that superinfection generally occurred with decreasing frequency as the interval between exposures to each genotype increased. For both the equal virulence and unequal virulence genotype pairs, the frequency of superinfection was the same regardless of which genotype was used in the primary exposure. However, the ability to replicate in the context of superinfection did not differ between the genotypes of equal or unequal virulence tested here. For both genotype pairs, the mean viral load of the secondary virus was significantly reduced in superinfection, while primary virus replication was unaffected. Our results demonstrate, for the two genotype pairs examined, that superinfection restriction does occur for IHNV, and that higher virulence did not correlate with a significant difference in superinfection fitness. To our knowledge, this is the first assay to examine the role of virulence of an RNA virus in determining superinfection fitness dynamics within a natural, vertebrate host.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The role of virulence for in vivo superinfection fitness of a vertebrate RNA virus
Series title Journal of Virology
DOI 10.1128/JVI.00089-13
Volume 87
Issue 14
Year Published 2013
Language English
Publisher American Society for Mivrobiology
Contributing office(s) Western Fisheries Research Center
Description 13 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Virology
First page 8145
Last page 8157