Saade Georges

Abstract :

Respiratory co-infections in pigs are more common than infections caused by a single pathogen. First of all, we identified the viral and bacterial porcine co-infections studies and we detailed the possible molecular consequences on the porcine host. The porcine reproductive and respiratory syndrome virus (PRRSV) and the swine Influenza A Virus (swIAV), are major contributors to the porcine respiratory disease complex. SwIAV primarily infects epithelial cells while PRRSV infects cells expressing CD163 such as alveolar macrophages (AM). In order to evaluate the antiviral response of the porcine host and to study the effect of a pre-infection with PRRSV on the réplication of swIAV, a series of co-infections and superinfections were carried out on tracheal epithelial cells and precision-cut lung slices. The results showed that PRRSV can interfere with swIAV infection and alter the cellular antiviral response without infecting epithelial cells. This effect of PRRSV appears to be less important following an increase in the delay between viral inoculations. Finally, a series of experiments enabled us to identify the pathogens circulating in pigs from a local slaughterhouse and to assess the effect of the various bacterial and viral infections, on the alveolar macrophages trained immunity and their ability to replicate viruses in case of superinfection.

Key words :

Pig, coinfections, swIAV, PRRSV, interference, innate immunity