Significance of Microbiology for Medicine
The realization that microorganisms cause disease radically changed approaches to medical care. An active search for methods to combat infections began on several fronts:
- Sanitary measures: breaking transmission pathways and destroying microbes in the external environment (disinfection).
- Clinical measures: studying disease development mechanisms and early diagnostics.
- Pharmacology: creating antimicrobial therapy agents.
Fundamental research into pathogen properties, such as pathogenicity and drug susceptibility, led to the development of antimicrobial drugs (antibiotics, chemotherapeutic agents) and immunobiological products (vaccines, sera). The result was a global reduction in morbidity and the complete eradication of certain infections.
Periodization and Origin of the Science
The presence of infections in deep antiquity is proven by findings of bacterial antigens and specific lesions in ancient burials. Microbiology originated before the discovery of microbes themselves based on conjectures about external factors causing disease.
It is customary to divide the history of the science into five periods:
- Heuristic.
- Morphological.
- Physiological.
- Immunological.
- Molecular genetic.
Heuristic Period: From Miasmas to Living Contagions
This began in the Ancient world (3rd–4th centuries BC). Hippocrates hypothesized that diseases are transmitted from person to person through inanimate substances from marshy places—"miasmas".
Despite a lack of knowledge about microbes, people empirically used their metabolic products in baking, winemaking, and brewing.
In the 15th–16th centuries, Girolamo Fracastoro made a breakthrough by proposing the theory of "living contagions." He believed that pathogens were invisible living entities transmitted through the air and objects. Fracastoro, who became a founder of epidemiology, proposed the first protective measures: patient isolation and room fumigation.
Morphological Period and Early Visualizations
In the 17th and 18th centuries, with the invention of the microscope, the morphological stage began. The Dutchman Antoni van Leeuwenhoek, by grinding lenses, created a microscope with up to 300x magnification. Studying dental plaque, water, and other fluids, he discovered microorganisms, calling them "animalcules" ("little animals"). He published his sketches in the Royal Society of London.
In Russia, the microscope was first brought by Peter I after a visit to Leeuwenhoek. The first domestic researcher of microbes was M. M. Terekhovsky, who used his experiments to refute the theory of spontaneous generation of life.
Proof of the Etiological Role of Microbes
For a long time after the discovery of microbes, their role in the development of diseases remained unclear. To prove their pathogenicity, researchers conducted animal experiments and even resorted to self-infection.
Russian physician Danila Samoilovich infected himself with material from a plague bubo (and survived). Similar heroic experiments were also conducted by M. von Pettenkofer, Ilya Mechnikov, and D. K. Zabolotny (with cholera). These studies definitively confirmed the infectious nature of many diseases.