Pathogenic Microorganisms - 222 PHARM

Pathogenic Microorganisms - 222 PHARM

• Topics covered include introduction to microorganisms, objectives, microbiology definition, scope of microbiology, classification of living organisms, prokaryotic and eukaryotic cells, prokaryote vs eukaryote, domains, kingdoms, binomial nomenclature system of classification, bacterial shapes, and bacterial arrangements.
• Microbiology is the study of very small living organisms (microorganisms, M.O.) that cannot be seen with the naked eye.

Introduction to Microbial World

• Microbiology is the study of living things too small to be seen without a microscope.
• Microorganisms can be beneficial or pathogenic.
• Microorganisms include bacteria, archaea, fungi, protozoa, algae, and viruses.

Objectives

• Define microorganisms and the scope of microbiology.
• Understand the microbial world and microbial classification.
• Differentiate prokaryotes and eukaryotes.
• Describe various types, shapes, and arrangements of microorganisms under a microscope.

What is Microbiology?

• Microorganisms (M.O) are too small to see.
• Microbiology studies M.O,
• Most microbes are beneficial,
• Medical microbiology studies disease-causing microbes.

Scope of Microbiology

• Infectious agents – includes bacteria, fungi, protozoa, helminths and viruses.
• Viruses are acellular, non-living agents.

Classification of Living Organisms

• Based on cell type (prokaryotic/eukaryotic)
• Based on domains (Woese et al. 1990) -> Bacteria, Archaea, Eukarya.
• Based on kingdoms (Cavalier-Smith 2000) -> example Archaebacteria,Eubacteria, Animalia, Plantae,Eumycota, Protista, Chromista.

Prokaryotic & Eukaryotic Cells

• Prokaryotic cells lack a nucleus and other membrane-bound organelles.
• Eukaryotic cells have a nucleus and membrane-bound organelles. (Visual aid included)

Prokaryote vs. Eukaryote

• Key differences in cell structures and organization. (Data Table included)

Domains

• Three domains exist: Bacteria, Archaea, Eukarya.

Kingdoms

• Six (or seven) kingdoms of living organisms are present. Examples include : Archaebacteria, Eubacteria, Animalia, plantae, fungi, protista, Chromista.

Binomial Nomenclature System

• Organisms are named using a two-part naming system: Genus species (e.g., Staphylococcus aureus).
• Genus is capitalized and species is lowercase.
• Both are italicized.
• Genus can be abbreviated (e.g., E. coli).

Bacterial Shapes

• Three basic shapes: Bacilli (rod-shaped), Cocci (spherical), Spiral (helical).
• Some bacteria are pleomorphic—meaning their shape varies.

Bacterial Arrangements

• Cocci can arrange in various patterns (e.g., diplococci, streptococci, tetrads)
• Bacilli can arrange in patterns (e.g., single, pairs). (Visual representation of arrangements included)