The contribution of perm scientists to the development of medical microbiology. On the 125th anniversary of professor A.V. Pshenichnov

March 23, 2025 marked the 125^th anniversary of Professor A.V. Pshenichnov, the founder of the Perm microbiological school, Honored Scientist, and Laureate of the State Prize. The article provides a historical overview on the main scientific achievements of Professor A.V. Pshenichnov and his students. His most significant researches are in the field of rickettsiosis, in particular epidemic typhus and Volyn fever, as well as tick-borne encephalitis. He and his colleague B.I. Raikher were awarded the State Prize for the development of a vaccine for the prevention of epidemic typhus, which played a decisive role in the fight against this disease during the Great Patriotic War. Students and followers of Professor A.V. Pshenichnov continue the traditions established by him as a long-term head of the department. At present, the department staff, together with specialists in various fields, are conducting successful researches on current issues of medical microbiology.