上商充通大 Definition Shanghai Jiao Tong University In the strictest sense,antibiotics are antibacterial substances produced by various species of microorganisms (bacteria, fungi,and actinomycetes)that suppress the growth of other microorganisms. Common usage often extends the term antibiotics to include synthetic antimicrobial agents,such as sulfonamides and quinolones.Shanghai Jiao Tong University Definition In the strictest sense, antibiotics are antibacterial substances produced by various species of microorganisms (bacteria, fungi, and actinomycetes) that suppress the growth of other microorganisms. Common usage often extends the term antibiotics to include synthetic antimicrobial agents, such as sulfonamides and quinolones