Lysozyme, an antimicrobial enzyme that is a component of secretions such as tears and saliva.

Digital facsimile from royalsocietypublishing.org at this link

Discovery of the growth-inhibiting action of Penicillium on certain bacteria. 

In 1945 Fleming shared the Nobel Prize in Physiology or Medicine with Ernst Boris Chain and Sir Howard Walter Florey "for the discovery of penicillin and its curative effect in various infectious diseases." See also Nos. 10784 and 12599.

In this paper Fleming first described the use of penicillin as an antibacterial agent in man, and reported on experiments using it as a wound dressing for septic wounds. He also corrected the species name from Penicillium rubrum (1929) to Penicillium notatum.

(Thanks to Juan Weiss for this reference and its interpretation.)

Fleming was the first to measure blood levels of penicillin after intramuscular, intradermal, inravenous and continuous drip administration in order to determine the correct dosage. He described his micro-measurement methods in this paper.

(Thanks to Juan Weiss for this reference and its interpretation.)

In this paper Fleming and colleagues explained how to choose routes of administration of penicillin as well as dosage, and reproduced the graphs/figures that showed blood levels achieved with different doses and routes of administration.
Fleming was the first to use Procaine mixed with penicillin in order to alleviate the tremendous intramuscular pain of the injections. He showed that the anesthetic did not affect the bacterial killing power of the antibiotic. With M. Y. Young, A. J. E. Rowe.

(Thanks to Juan Weiss for this reference and its interpretation.)

This was the only book that Fleming ever published on penicillin. American issue, Philadelphia: Blakiston, 1946.