In 1940, she became assistant professor of bacteriology at
Howard University College of Medicine in Washington, D.C. In 1952, Moore became chair of the department of bacteriology. She was subsequently promoted to the position of associate professor. In 1957, Moore stepped down from her departmental leadership position, but continued to teach and conduct research on bacteriology at the university. She retired from teaching at Howard University in 1973 and held the position of the associate professor emeritus of microbiology until 1990. It is unclear whether she ever received tenure despite her long career of teaching and research. which she joined in 1936. As a Black woman, she faced restrictions to attending American Society for Microbiology meetings, particularly where
Jim Crow laws were in effect, mandating segregation in hotels and conference venues. Moore's research was published in a wide variety of professional journals and publications, from the
Journal of the American Medical Association to the
American Journal of Physical Anthropology. Some of her research included significant contributions in the study of blood types, and the reaction of specific pathogens to different classes of antibiotics.
Research into blood types Her publications in the 1950s were on blood types among African Americans. Moore's study took place at
Howard University College of Medicine. The university population included African Americans from throughout the United States. With few exemptions in the states represented, this diversity made her participants a random sample for Black Americans. Moore's study was used for a teaching program. It was conducted by pricking the fingers of participants to collect blood samples and using macroscopic and microscopic processes to observe the blood samples that were collected. Moore's experiment was split into three series, the first two series determined ABO blood types and the third series was used to determine the subgroups of ABO that are MN and Rh. Throughout Moore's research she compared her results to that of the scientists who preceded her, such as Landsteiner and Weiner, who discovered the Rh factor in human blood. When concluding her experiment, she was able to determine that the results from her MN study did not fully correspond with the results of the former experimenter, but her investigation into Rh types did correspond with that of the previous experimenter. Comparison of her results to those of the other experiments suggested that Rh blood types might be a good starting ground for studying and building a foundation of knowledge about different racial backgrounds. Beyond Moore's study of Rh and MN blood types, she also discovered in a group of 2496 African Americans that 51.94% of them were in Group O, 17.32% in Group B, only 27.3% were in Group A, and 3.01% in AB. That data corresponded with an earlier experiment in
physical anthropology whose results demonstrated the types O and B were more prominent in African Americans than the other blood types.
Research on dental caries (cavities) Dr. Moore was the only author of a 1938 paper titled "The Immunology of Dental Caries", about the etiological agents contributing to formation of dental caries (cavities). The article was published in
The Dentoscope, a publication by the Howard School of Dentistry. Her investigations yielded an association of
Lactobacillus acidophilus with cavities which she hypothesized to be an instigating factor. Specifically, the organism was shown to satisfy the first two rules of
Koch's postulates, while the other two had previously been demonstrated in vivo. It was shown that
L. acidophilus was present in the mouths of patients susceptible to cavities, but the species was absent from patients without cavities. She therefore hypothesized the saliva of patients without cavities had antibiotic properties against
L. acidophilus. It is now known that this association with cavities occurs after the cavities have already formed, rather than this species being causal to their formation. She also hypothesized that having a diet high in carbohydrates is a predisposing factor for cavity formation by selecting for specific species including
L. acidophilus. It was shown that there was a correlation between skin reactions to
L. acidophilus filtrate injections and susceptibility to cavities. These reactions were not similar to those described in the
Dick test and the
Schick test, both of which were used to detect different types of biological toxins (see Dick test and Schick test). Additionally, no toxins had been identified from
L. acidophilus, leading Dr. Moore to conclude that the likely explanation was an allergy to the bacterium. However, it was also noted that patients free of caries (cavities) also had skin reactions to
L. acidophilus filtrate. The study also included experiments of vaccines on children. Vaccines with different phases of
L. acidophilus were included; some vaccines had the rough (R) phase, some had the smooth (S) phase, and some had a mixed phase with both (see
Griffith's experiment). R phase vaccines caused abscesses at the site of injection and also increased agglutinin titer, while smooth vaccines did not. Mixed phase vaccines also caused abscesses. The causative agent of these abscesses was not determined.
Research on gut microbiomes In 1963 she published research on the sensitivity of gut microorganisms to antibiotics. The 1963 publication studied gut isolated microbes of the Death's Head Cockroach,
Blaberus caniifer Burmeister, by isolating pure cultures from the cockroach gut and culturing them on trypticase soy agar. Moore later tested the cultures for antimicrobial susceptibility and antibiotic resistance by placing disks containing antibiotics at various concentrations on the plates (see
Disk diffusion test). After incubation, Moore considered the bacteria sensitive to the antibiotic if there was a zone of inhibition present around the disk and as resistant to the antibiotic if there was no zone of inhibition around the disk. Additionally, the study investigated whether antibiotics were bacteriostatic or bactericidal by removing agar from the zones of inhibition and culturing in nutrient broth. If these liquid cultures showed growth, the antibiotic was concluded to be bacteriostatic, and if there was no growth, the antibiotic was concluded to be bactericidal. Her work is considered some of the earliest on microbiomes. ==Honors==