Fig. 1

a Proven targets for antibacterial drugs. Protein biosynthesis at the ribosome is targeted by different classes of antibiotics such as macrolides, tetracyclines, aminoglycosides. Cell membrane can be targeted by some antibiotics such as Polymyxin B. These antibiotics alter bacterial outer membrane permeability and finally destabilize outer membrane of bacteria. The fluoroquinolone antibiotics inhibit DNA replication by trapping a complex of DNA bound to the enzyme DNA Gyrase. Cell-wall biosynthesis is inhibited by the various classes of antibiotics. b Multiple antibiotic resistance mechanisms in bacteria. Efflux pumps remove the antibiotics from bacteria (e.g. Fluoroquinolones and trimethoprim resistance in P. aeruginosa). Destruction enzymes that degrade the antibiotics (β-lactams in Enterobacteriaceae). Modifying enzymes which change the antibiotic structure (e.g. chloramphenicol or fosfomycin in P. aeruginosa)