Introduction to microbiology

1
Introduction to microbiology

• Dr. Rambhala Nagamani regional lab.
  blood bank Dammam.

2
Microorganisms - heterogenous group of several
distinct classes of living beings.

• Bacteria, viruses, fungi, parasites.
• Different in size, cell constituents, growth
  characters, pathogenicity.
• Size
• bacteria- microns (1micron 1/1000 m.m)
• viruses- nanometer(1/1000micron)
• some fungi parasites are microscopic and
  some aremacrscopic.

3
Microscopy

• Bacteria visualised by stained preparation
• GRAM STAIN- essential procedure only method to
  study the morphology.
• Depending on grams reaction,
• gram positive- cocci, bacilli.
• Gram negative- cocci, bacilli.
• Other shapes- spiral,comma shaped etc.

4
Significance - differ in their staining
character, growth requirements, susciptibility
to anti biotics, pathogenicity.

• Other types of bacteria-
• acid fast bacilli- mycobacteria
• mycoplasma - cell wall lacking
• chlamydia- intracellular pathogens that lack
  definite bacterial characters.
• Rickettsia- a group of bacteria same as above.