Rifampin--Rifampin is derived from rifamycin, a product of Amycolatopsis mediterranei that has been in natural environments for a long time (found in soil). Resistance genes may have evolved in response to rifampins in natural environments, as well as in clinical situations.

Rifampin is active against a number of bacteria and is very potent, making it suitable for treatment of drug-resistant infections. It is an antibiotic medication most commonly used in the treatment of Hansen's disease, also known as leprosy, and drug-resistant tuberculosis (both mycobacteria). It may be prescribed for the treatment of other conditions caused by bacterial infections as well, depending on the specifics of a patient's case.
Any of various mainly toxic antibiotics derived from strains of the soil bacterium Bacillus polymyxa and used to treat various infections with gram-negative bacteria.

A class of broad-spectrum antibacterial drugs of which the main ophthalmic agents are ciprofloxacin and ofloxacin. They are used topically in 0.3% solution. They are effective against the majority of gram-negative pathogens, including Haemophilus, Neisseria gonorrhoeae, Chlamydia trachomatis, Pseudomonas aeruginosa (especially ciprofloxacin), staphylococci and streptococci. They are used in the treatment of conjunctivitis, blepharitis, keratoconjunctivitis and corneal ulcers.

Extra Credit: The first generation of the quinolones begins with the introduction of nalidixic acid in 1962 for treatment of gram negative urinary tract infections in humans. Nalidixic acid was