| Influenza A viruses are highly pleomorphic in morphology producing two distinct morphological variants, spheres and filaments. The filamentous morphology is most often detected in primary human isolates, but is readily lost during serial passage in egg or tissue culture. Therefore, spherical strains of influenza virus are more often used for laboratory purposes. Although the physical composition of the two types of particles has been characterized extensively, a comparison of filamentous and spherical strains in vivo has never been fully examined. Thus, we utilized a murine model of pathogenesis to discern any similarities and differences between the two morphological variants in an animal model. In addition, since previous studies have demonstrated that animals exposed to bacterial pathogens while recovering from an influenza A virus infection exhibit exacerbated disease symptoms, and all studies utilized spherical strains of influenza virus, we wished to further characterize the filamentous influenza strains by determining their effects on bacterial disease exacerbation. By utilizing a filamentous strain of influenza A virus, we can more accurately mimic a clinical course of infection to elucidate mechanisms by which this viral-bacterial synergy is occurring. |
