Introduction To Microbiology

INTRODUCTION TO MICROBIOLOGY

DEFINITIONS • SCIENCE ---The study or collection of knowledge of natural events and materials in an orderly fashion for the purpose of learning the basic laws that govern these events. • BIOLOGY--- The study of living organisms and how they interact with the environment around them. • MICROBIOLOGY--- The study of very small living organisms (Microorganisms or Microbes)

• Microorganisms (Microbes) • 87% Beneficial Microorganisms

10% Opportunists

3% Pathogens

HISTORICAL MILESTONES

• 3.5 billion years ago-- Fossils of primitive microbes found dated. • 3180 BC--- earliest account of pestilence occurred in Egypt. • 1900 BC--- Bubonic plague (Greek army) • 1500 BC---Ebers papyrus was discovered in a tomb in Thebes, Egypt containing description of epidemic fever. • 1122 BC– smallpox epidemic in China • 790, 710 and 640 BC--- epidemics occurred in Rome • 430 BC– Epidemics in Greece. • 1493– Syphilis first appearance was in Europe and was given many names: Neopolitan Disease (French), French or Spanish Disease(Italians), French pox (English)

PIONEERS IN THE SCIENCE OF MICROBIOLOGY • ANTON VAN LEEUWENHOEK (1632-1723) • Father of Microbiology, Father of Bacteriology, Father of Protozoology • Made the single lens microscopes or simple microscopes. • Discovered “animalcules” (live bacteria and protozoa) • Spontaneous generation or abiogenesis arose from his findings--- life can arise spontaneously from nonliving materials.

LOUIS PASTEUR (1822-1895)

• French chemist • Discovered the process of alcoholic fermentation. • Disproved the Spontaneous generation or Abiogenesis. • Introduced terms “aerobes” and “anaerobes” • Pasteurization and sterilization • Discovered infectious agents that were causing the silkworm diseases. • Gave significant contributions to the Germ theory of Disease– specific MO cause specific infectious disease. • Developed a vaccine to prevent rabies in dogs and used it as a vaccine to treat human rabies.

ROBERT KOCH (1843-1910) • Gave significant contributions to the Germ Theory of disease • Koch’s postulates--- scientific steps • Developed methods of fixing, staining and photographing bacteria. • Developed methods of cultivating bacteria on solid media. • Discovered Bacterium (Mycobacterium tuberculosis and Vibrio cholerae – El Tor)

OTHER PIONEERS • Edward Jenner—Late 1700 --discovered 1st vaccine (used for smallpox) • Joseph Lister (1865-1870)and Ignaz Semmelweiss (1847) --Aseptic techniques • Paul Erlich (1890’s to 1900) --Developed the 1st chemotherapeutic agent: Salvarsan vs. Syphilis.

BRANCHES OF MICROBIOLOGY • • • • • •

Bacteriology– the study of Bacteria Phycology– the study of Algae Mycology– the study of Fungi Protozoology– the study of protozoa Virology– the study of viruses Immunology- the study of immune response

APPLICATION OF MICROBIOLOGY • Indigenous microflora--- beneficial • Opportunistic pathogens—colonize or inhabit bodies. • MO involve in the decomposition of dead organisms---saprophytes • MO cause 2 categories of diseases 1. Infectious disease– pathogen—colonize— disease. 2. Microbial intoxication—pathogen—toxin— humans ingest toxin---disease.

FUNCTIONAL CLASSIFICATION

• GENERAL MICROBIOLOGY– The study & classification of MO & how they function. • MEDICAL MICROBIOLOGY—the study of pathogens, the disease they cause and the body’s defenses against disease. • VETERINARY MICROBIOLOGY– the study of the spread and control of infectious diseases among animals. • AGRICULTURAL MICROBIOLOGY– the study of the beneficial and harmful role of microbes on the soil, plants, crops and foods. • SANITARY MICROBIOLOGY—purification and processing of water supplies and processing and disposal of garbage and sewage wastes.

• INDUSTRIAL MICROBIOLOGY– growth and maintenance, research of microorganisms to produce commercial and pharmaceutical products. 1. Industrial microbiologists---produce commercial products. 2. Applied Microbiologists--- produce commercial products. • ENVIRONMENTAL MICROBIOLOGY (MICROBIAL ECOLOGY)– cycling of elements by microbial, environmental and geochemical processes. • MICROBIAL PHYSIOLOGY AND GENETICS– function of MO, structure and physiology.