In this study, global intra- and extracellular metabolic profiles were exploited 
to investigate the impact of antibiotic compounds with different cellular 
targets on the metabolome of Staphylococcus aureus HG001. Primary metabolism was 
largely covered, yet uncommon staphylococcal metabolites were detected in the 
cytosol of S. aureus, including sedoheptulose-1,7-bisphosphate and the 
UDP-MurNAc-pentapeptide with an alanine-seryl residue. By comparing the 
metabolic profiles of unstressed and stressed staphylococcal cells in a 
time-dependent manner, we found far-ranging effects within the metabolome. For 
each antibiotic compound, accumulation as well as depletion of metabolites was 
detected, often comprising whole biosynthetic pathways, such as central carbon 
and amino acid metabolism and peptidoglycan, purine, and pyrimidine synthesis. 
Ciprofloxacin altered the pool of (deoxy)nucleotides as well as peptidoglycan 
precursors, thus linking stalled DNA and cell wall synthesis. Erythromycin 
tended to increase the amounts of intermediates of the pentose phosphate pathway 
and lysine. Fosfomycin inhibited the first enzymatic step of peptidoglycan 
synthesis, which was followed by decreased levels of peptidoglycan precursors 
but enhanced levels of substrates such as UDP-GlcNAc and alanine-alanine. In 
contrast, vancomycin and ampicillin inhibited the last stage of peptidoglycan 
construction on the outer cell surface. As a result, the amounts of 
UDP-MurNAc-peptides drastically increased, resulting in morphological 
alterations in the septal region and in an overall decrease in central 
metabolite levels. Moreover, each antibiotic affected intracellular levels of 
tricarboxylic acid cycle intermediates.