[1] It was a chance visit to her home town by Harold Addison Woodruff that inspired Rountree and persuaded her father that she should take a master's degree and become a bacteriologist.

She had enjoyed the relaxed attitude there but male colleagues had not spoken to her during her work breaks and she was sure that a man successfully completing three years of research would have been retained.

[5] After a year of food testing during the war,[5] she started at the Royal Prince Alfred Hospital in 1944[5] where she was suspected of recruiting communists.

The strain appeared initially during a study of infections in the nursery at Royal North Shore Hospital in Sydney, Australia.

Strain 80/81 eventually came to be found in Australia, New Zealand, Canada, Great Britain, and across the United States.

The 1950 epidemics in nurseries gave bacteriologists like Rountree and others an opportunity to revitalize infection control procedures in the absence of an effective antibiotic to treat the 80/81 strain.

[8][9] In 1956, Rountree and other medical and scientific professionals co-authored the first manual pertaining to the management of hospital nursery staphylococcal infection.

[5] Much of Rountree’s work throughout her career was devoted to the study of Staphylococcus aureus, also known as 'golden staph', in addition to investigating its impact on the sterility of the hospital environment.

One such piece includes “Observations on the distribution of Staphylococcus aureus in the atmosphere of a surgical ward”,[18] which was published in 1962 in volume 60 of The Journal of Hygiene.

Their work demonstrated that there was one predominant strain in the hospital, found in the air, wounds, nasal cavities, and bedding.