Slideshows Images Quizzes

Copyright © 2018 by RxList Inc. RxList does not provide medical advice, diagnosis or treatment. See additional information.

Definition of Penicillin

  • Medical Author:
    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

Penicillin: The most famous of all antibiotics, named for the fungal mold Penicillium notatum from which it is derived. Penicillin acts by destroying the cell wall of bacteria.

Penicillin is active against a number of types of bacteria including Streptococcus pneumoniae, Listeria, Neisseria gonorrhoea, Clostridium, Peptococcus, and Peptostreptococcus.

Most staphylococci now are resistant to penicillin. Today, manyderivatives of penicillin are available which act on more types of bacteria than penicillin itself.

The name "penicillium" was taken from the Latin "penicillum" meaning "a painter's brush" because the fronds of the fungus were thought to look like a painter's brush.

For information about the pharmacology of penicillin, see Penicillin V, See also: Penicillin history.


Bowel regularity means a bowel movement every day. See Answer
Reviewed on 12/11/2018

Health Solutions From Our Sponsors