Microbiology

+ The study of microscopic organisms' -> very small living things that can only be seen with magnifications (e.g., microbes, germs, bugs...)

+ It also involves the study of the specific interaction between microorganisms and humans, and between microbes and their environment.

-> Study of the defense system against infections

-> monitoring & controlling the speed of disease

-> the study of bacteria

-> the study of protozoa & parasitic worms

-> the study of fungi

the study of viruses

• -> altering the genetic makeup of organisms,
• to produce substances such as drugs and hormones,
• or to develop new organisms

-> the study of classification of organisms based on similarities. It includes:

1. Classification - arrangement into groups

2. Nomenclature - naming the organisms

3. Identification - description & characterizations

• 1. Kingdom
• 2. Phylum (division)
• 3. Classes
• 4. Order
• 5. Family
• 6. Genus
• 7. Species

(Least common <-> Most common)

Humans belong to:

• 1. Kingdom -> Animalia
• 2. Phylum -> Chordata
• 3. Class -> Mammalia
• 4. Order -> Primates
• 5. Family -> Hominoidea
• 6. Genus -> Homo
• 7. Species -> Sapiens

• -> a system of naming the organisms using a 2-part latin combination.
• It consists of the genus name and a specific name for the species; both are italicized.
• + Genus name is capitalized.
• + Species name is in lower-case.
• Ex: Homo sapiens.

1) Two - kingdom concept by Linnaeus

2) Proposal of a third kingdom

3) The 5 - kingdom concept by Whittake

• + Animal -> protozoa
• + Plant -> other microorganisms
• + This was impractical since some microorganisms were animal-like, some were plant-like, and some were both.

+ Protista -> had the features of both animals and plants.(Ex: bacteria, algae, photozoa,...)

• It included:
• + Prokaryotes (Monera) -> Bacteria
• + Protista -> eukaryotic, unicellular, such as algae & protozoa
• + Myceteae (fungi) -> eukaryotic; such as molds & yeasts
• + Plantae -> eukaryotic; such as plants
• + Animalia -> eukaryotic; such as animals

• + Prokaryotes:
• - smaller cells
• - lack nucleus
• - lack organelles
• - all microorganisms'
• - simple structure
• - Subdivided into: Eubacteria (typical) & Archaebacteria (atypical)

• + Eukaryotes:
• - larger cells
• - contain nucleus
• - contain membrane bound organelles
• - only some are microorganisms
• -complex structures

-> the development of the Microscope.

+ Antony Van Leeuwenhoek is considered the father of microscopy (simple: microscope), bacteriology, and protozoology.

+ Microscope developed provided up to 300 times magnification, to observe microbes (or animalcules) in rainwater, in liquid in which peppercorns had soaked, and in material scraped from his teeth.

+ Antony Van Leeuwenhoek is considered the father of microscopy (simple: microscope), bacteriology, and protozoology.

+ Microscope developed provided up to 300 times magnification

+ to observe microbes (or animalcules) in rainwater, in liquid in which peppercorns had soaked, and in material scraped from his teeth.

• The school of thought on the origin of microorganisms:
• 1. Abiogenesis (spontaneous generation) -> believe that some forms of life could arise spontaneously from nonliving matter. (believed until mid-19th century)

2. Biogenesis -> belief that living cells arise only from preexisting living cells.

-> believe that some forms of life could arise spontaneously from nonliving matter. (believed until mid-19th century)

-> belief that living cells arise only from preexisting living cells.

1) The discovery of spores & sterilization.

2) The development of aseptic techniques.

3) The discovery of pathogens and the Germ theory of disease.

Endospores -> heat resistant; not completely destroyed by heat

Sterilization -> the process of destroying all forms of life including spores from the objects and materials.

-> Used to reduce the disease-causing microorganisms.

• Pathogens:
• -> disease-causing microorganisms.
• The germ theory of disease:
• -> Microbes are the causative agents of some diseases
• -> Koch developed lab techniques to isolate and study individual types of microbes.
• -> Koch's postulates were set to prove that a specific microbe causes a specific disease.

• fermentation (used to make wine) 
• -> Pasteur found out that microorganisms called yeasts convert the sugars to alcohol in the absence of air.

-> He also found out that spoilage and souring (of wine, milk,..) are caused by bacteria; which can change the alcohol in these beverage into vinegar in the absence of air.

-> Pasteur's solution to the problem of spoilage and souring of wine, milk,.. caused by bacteria -> heat the wine and milk,.. just enough to kill most of the bacteria.

• -> treament of disease by using chemical substances.
• 1) Antibiotics -> chemicals produced naturally by bacteria and fungi to act against other microorganisms.

2) Synthetic drugs -> agents prepared from chemicals in the laboratory.

+ Paul Ehrlich (German physician) searched for an agent that could destroy a pathogen without harming the infected host.

+ Salvarsan (the first synthetic drug)-> an arsenic derivative effective against syphilis.

+ Sulfa drugs -> destroyed microorganisms; derivatives of dyes.