Neomycin

Neomycin is an antibiotic that is found in many topical medications such as creams, ointments and eyedrops.

It can also be given orally, where it is usually combined with other antibiotics. Oral use is extremely rare because neomycin is extremely nephrotoxic, especially compared to other aminoglycosides.

Neomycin was discovered in 1949 by the microbiologist Selman Waksman. It is produced naturally by the bacterium Streptomyces fradiae.

Neomycin has a broad spectrum of effect, killing both gram-positive and gram negative bacteria. It is relatively toxic to humans, and some people have allergic reactions to it.

Neomycin is used in the lab in agar plates when culturing organisims anaerobically. Neomycin stops the growth of gram-negative bacilli and staphylcocci, allowing Streptococcus species to grow more abundantly.