Jean Orr-Ewing

Jean Orr-Ewing (28 April 1897 – 17 November 1944) was a pathologist and a bacteriologist[1] who was part of the small team of scientists who first isolated and purified penicillin for the treatment of bacterial infection.

She continued her medical training with clinical work at St Mary's Hospital, London, taking the Conjoint Diploma in 1923,[2] and being awarded a Bachelor of Medicine in 1924.

[8](p306)[3] It was St Mary's Hospital, London where Alexander Fleming first discovered penicillin in 1928 (but was not able to isolate the main compound so it could be properly purified for production in large amounts).

Orr-Ewing's and Gardner's roles involved investigating how newly isolated penicillin reacted with other organisms,[14][15] and "making a thorough study of the principal pathogenic bacteria and their sensitivity to penicllin".

[16] "It was they who, on observing the growth of the sensitive bacteria in the presence of penicillin, came to the conclusion that it did not act like an antiseptic or an enzyme, but rather, as a blocker of the normal process of cell division".