On the Antibacterial Action of Cultures of a Penicillium, with Special Reference to their Use in the Isolation of B. influenzæ
Alexander Fleming
Summary
Fleming reported that a mould of the genus Penicillium, which had contaminated a culture plate, produced a diffusible substance—which he named 'penicillin'—that inhibited the growth of many common pathogenic bacteria. He characterized the antibacterial spectrum and potency of the crude culture filtrate, showing it was strongly active against Gram-positive organisms (such as staphylococci and streptococci) while sparing certain Gram-negative bacilli. He proposed using the agent both as a selective culture medium for isolating Bacillus influenzae and as a relatively non-toxic antiseptic.
Key findings
- A Penicillium mould secreted a diffusible antibacterial substance ('penicillin') that strongly inhibited Gram-positive cocci such as staphylococci, streptococci, and pneumococci.
- Penicillin's selective action allowed its use as a culture-medium additive to suppress contaminating organisms and aid isolation of penicillin-insensitive bacteria such as B. influenzae.
- Crude culture filtrate showed marked antibacterial activity even when highly diluted and appeared non-toxic to tissue and leucocytes, suggesting therapeutic potential.
Subjects & keywords
Cite this paper
Alexander Fleming (1929). On the Antibacterial Action of Cultures of a Penicillium, with Special Reference to their Use in the Isolation of B. influenzæ. British Journal of Experimental Pathology. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2048009/
@article{fleming1929antibacterial,
author = {Alexander Fleming},
title = {On the Antibacterial Action of Cultures of a Penicillium, with Special Reference to their Use in the Isolation of B. influenzæ},
journal = {British Journal of Experimental Pathology},
year = {1929},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2048009/}
}