Lipid profiling of the secondary infecting bacteria with porcine reproductive and respiratory syndrome virus, including Streptococcus suis serotype 2, and their hosts.

The lipid profile of bacteria associated with swine respiratory diseases remain unknown. This study analyzed the lipids of common bacteria, secondary to porcine reproductive and respiratory syndrome virus (PRRSV) infection, as well as lipid profile of the host. Streptococcus suis serotype 2 (SS2), Streptococcus equi subsp. zooepidemicus (SZ), Actinobacillus pleuropneumoniae serotype 7 (APP7), Haemophilus parasuis serotype 5 (HP5) and Pasteurella multocida type A (PM) were analyzed using the liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS-MS) method. Phosphatidylcholine (PC), oxidized PC, phosphatidylethanolamine (PE), phosphatidylinositol (PI), lysophospholipids (LPLs)[lysophosphatidic acid (LPA), lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), lysophosphatidylinositol (LPI)], fatty acids (FAs) and their metabolites [arachidonic acid (20:4 AA), docosahexaenoic acid (22:6 DHA), prostaglandins, epoxyeicosatrienoic acid (EET)] were detected in these bacteria. Sphingolipids [ceramide (Cer), sphingomyelin (SM), sphingosine-1-phosphate (S1P) and cerebroside (Cb)] were also detected. Samples (tissue, plasma and cell pellets) were collected from mouse and porcine models, as well as cell models, and analyzed using the above method. The resulting lipidomics data were then subjected to statistical analysis. Lipid profiles for specific tissues, male and female plasma, and cell lines (J774A.1and N2a) were obtained. Histopathological changes are thought to be associated with the lipid profile at local and circulating levels. Overall, lipid profiling has been achieved in five bacteria, as well as in hosts treated with SS2, LPS, and PRRSV. This contributes to our understanding of bacterial lipid biology and microbe-host interactions, as well as informing strategies against respiratory infections.