Microbiology Fundamentals

Microbiology

• Microbiology is the study of microscopic organisms, including bacteria, viruses, fungi, protozoa, and algae.
• In medicine, microbiology is used for disease prevention, treatment, and diagnostics.

History of Microbiology

• Antonie van Leeuwenhoek was the first to observe microorganisms using a microscope.
• Louis Pasteur developed pasteurization and vaccines, and disproved spontaneous generation.
• Robert Koch established Koch's postulates, linking specific microbes to diseases.

Types of Microorganisms

• Bacteria: Prokaryotic cells with diverse metabolic capabilities, typically having a cell wall, plasma membrane, cytoplasm, nucleoid, and ribosomes.
• Viruses: Non-cellular entities requiring a host for replication, composed of a capsid, genetic material (DNA or RNA), and sometimes an envelope.
• Fungi: Eukaryotic organisms, including yeasts and molds.
• Protozoa: Single-celled eukaryotes, often motile.
• Algae: Photosynthetic eukaryotes found in aquatic environments.
• Parasites: Single-celled organisms (e.g., Plasmodium, Giardia, Entamoeba histolytica) or worm-like parasites (helminths).

Classification of Bacteria

• Bacteria are classified based on shape, cell wall structure, metabolism, and genetic makeup.
• Classification by shape:
  • Cocci: Spherical bacteria (e.g., Streptococcus, Staphylococcus).
  • Bacilli: Rod-shaped bacteria (e.g., Escherichia coli, Bacillus).
  • Spirilla: Spiral or corkscrew-shaped bacteria (e.g., Spirillum).
  • Vibrios: Comma-shaped bacteria (e.g., Vibrio cholerae).
  • Spirochetes: Flexible, spiral-shaped bacteria (e.g., Treponema pallidum).