2. objectives
• Define and Classify Bacteria.
• State the different ways of bacterial infections spread.
• Mention the risk factors for bacterial infections.
3. Definition of Bacteria
• Bacteria are relatively simple in structure. They are
prokaryotic organisms-simple unicellular organisms with
no nuclear membrane, mitochondria, Golgi bodies, or
endoplasmic reticulum-that reproduce by asexual division.
4. Bacterial Classification
• Bacteria can be classified by their macroscopic and
microscopic appearance, by characteristic growth and
metabolic properties, by their antigenicity, and finally by
their genotype.
5. Bacterial Classification
• Growth characteristics; resist certain
antibiotics, ferment specific sugars, to
Macroscopic lyse erythrocytes, or to hydrolyze lipids.
• Colony characteristics;
color, size, shape, and smell
• Size
• Shape
Microscopic • Configuration of the organism
(cocci, rods, curved, or spiral)
• Retain the Gram stain
6. Gram Stain
Is the primary mean to distinguish
bacteria.
Allows clinicians to distinguish between
the two major classes of bacteria.
Is a rapid, powerful, easy test.
9. How does bacteria spread ?
Sneezing Interaction Physical Exchange Interaction
and with contact. of bodily with
Coughing tainted fluids. contamina
(air). food, surfa ted living
ces, and being.
water.
10. Infections Risk Factors
• medical risks
• past medical history
• family history
• current treatment
• social risks
• lifestyle
• travel history
• occupation
