Arachidonic acid targets pneumococcal fatty acid homeostasis. Streptococcus pneumoniae D39

Free fatty acids play an important role during infection by modulating immune responses, but also by directly functioning as antimicrobials. Particularly, the host’s long chain polyunsaturated fatty acids, not commonly found in bacterial pathogens, have significant antibacterial potential. Of these arachidonic acid (AA) is in high abundance, and in this study we show that upon infection with the Streptococcus pneumoniae the AA concentration in the blood increases. Hence, we investigated the transcriptmoic effects of AA on this extremely problematic bacterial pathogen. Overall design: Wild-type Streptooccus pneumoniae D39 cells were grown in C+Y media with or without supplementation of 62.5 uM arachidonic acid. Cells were grown from OD600 = 0.05 to 0.3. Total RNA was then isolated and the transcriptomes of treated and untreated cells was determined. Each sample represents a pool of three biological replicates.