Microbiology
o Microbiology: the study of organisms ??o Bacteria of medical importance
- 0.2 - 1.5 um in diameter 
- 3 - 5 um in length
Shape of Bacteria
o Cocci - spherical/ oval shaped (major 
groups)
o Bacilli - rod shaped
o Vibrios - comma shaped
o Spirilla - rigid spiral forms
o Spirochetes - flexible spiral forms
o Actinomycetes - branching filamentous 
bacteria.Cytoplasm - gel-like substance enclosed within the
cell membrane contains cytoplasmic inclusions,
ribosomes, mesosomes and nucleoid
B. Additional structures - plasmid, slime layer,
capsule, flagella, fimbriae (pili) and spores.o Microorganisms include: 
o ?Bacteria 
o ?Viruses 
o ?Fungi 
o ?Parasites {protozoa &helminthes (worms) }
o ?Algae
Antoni van Leeuwenhoek 1674.(father of 
microbiology)
- 1st person to actually see living microorganisms
Cell Types
There are several classes of living organisms
 Based on the organization of their cellular 
structures,
all living cells can be divided into two categories: 
 1.Cells that do not have membrane-bound 
organelles 
- called prokaryotic cells
Eukaryotic cell types - Animals, plants, fungi, 
protozoa, and algae
Prokaryotic cell types -
 Unicellular organisms such as bacteria and 
blue -green alga
Similarities:
both cell types are living cells
o All cells are surrounded by a plasma membrane.o In an eukaryotic cell, chromosomes are contained
in a membrane-enclosed organelle, the nucleus.Microorganisms are ubiquitous.Rigid cell wall
2.?2.3.4.5.6.7.8.