RNA-seq transcriptome of Staphylococcus aureus at stationary phase in Tryptic Soy Broth

A commensal of the human body, Gram-positive Staphylococcus aureus is also an opportunistic pathogen of increasing concern across the world. Able to grow without oxygen, the bacterium is capable of infecting many types of wounds on different parts of the body. But, chief amongst concerns about the bacterium is its increasing ability to resist a variety of antibiotics. Understanding the physiology of S. aureus provides one avenue for the discovery of drugs able to combat this pathogen, and more fundamentally, provides a glimpse into the biology of this bacterium that has a shared evolution history with humans. In particular, understanding how S. aureus has transformed from a commensal into an opportunistic pathogen with the acquisition of new genetic and physiological repertoire is a fascinating question yet to be fully answered. This contribution hopes to provide some fundamental information that could illuminate the questions posted above. Chiefly, the RNA-seq transcriptome of S. aureus at stationary phase (16 hrs) in Tryptic Soy Broth at 37 oC (ArrayExpress accession number: E-GEOD-77242) was analysed by an in-house MATLAB algorithm to yield a transcriptional picture that revealed the importance of DNA and chromosomal maintenance to the cell. Specifically, an ensemble of 0.5 million reads indicated that highly expressed genes were: chromosomal replication initiation protein, lipase, delta-hemolysin, quinol oxidase subunit I, clumping factor, accessory gene regulator protein A, accessory gene regulator protein C, DNA polymerase III subunit beta, quinol oxidase AA3 subunit II, and elongation factor Tu. Overall, understanding the stationary phase gene expression pattern of S. aureus could potentially point us to therapeutic strategies to combat this increasing important human pathogen, that, in some cases, have resisted treatment with our front-line antibiotics.