Alexandra Mastrogiannaki-Marini was born in Thymiana, Chios, but today she lives and works in Kyparissia, the seat of the municipality of Trifylia. She studied at the Medical School of the University of Athens. She served as a rural doctor in Pyrgi, Chios, and later worked at the Chios hospital. She specialized in Microbiology – Biopathology (Hematology – Biochemistry – Microbiology – Immunology) at the Agia Sofia Children's Hospital in Athens, under the internationally renowned professor of Microbiology, Antigoni Arsenis.

As a trainee, she participated in the research work of the Laboratory of the Hospital. She particularly worked on Hematology (Leukemias, Hemoglobinopathies) under the supervision of the late Aris Karaklis, then Director of the Hematology Laboratory and Blood Donation Department at Agia Sofia Children's Hospital. During her specialization, she completed the works: “Cilia Staining in Pseudomonas” and “Acinetobacter calcoaceticus as a cause of sepsis in neonates” (A. Mastrogiannaki, E. Malamou, A. Arsenis), which was presented at the Panhellenic Medical Conference in Athens in 1985. She participated in the research work “Mycoplasma as a cause of male infertility,” conducted under the supervision of Dr. Giamarellou, infectious disease physician, Professor of Pathology at the University of Athens. She has published several papers and participated in numerous conferences.

Since 1985, as a Microbiologist- Biopathologist, she has been offering her services in the Messinia region and the Trifylia province. She actively participates in sector conferences and seminars and collaborates with the Department of Microbiology of the University of Athens - Whonet program - on the resistance of community microbes to antibiotics. At the same time, she attends the courses organized by the Microbiology Society. She participates in the ATLAS program, which is the Central Support System for the Internship of Students of all HEIs in the country.