This ppt is about introduction to microbiology.

1. Introduction to Microbiology
Prasil Pradhan

2. What do you mean by Microbiology?
Study of living organisms that
are not directly visible to naked
eye but only under the
microscope.

3. What is Medical Microbiology ?
Study that deals with causative agents of
infectious diseases, their pathogenesis,
diagnosis and treatment.
– Bacteriology
– Virology
– Parasitology
– Mycology
– Immunology

4. Bacteria
• Prokaryotes
• Single celled organism
• Ubiquitous in every habitat
• 10 times more bacteria in human
body than human cells.
• Few species are pathogenic and
cause infectious diseases.

5. Virus
• Obligate intracellular
parasite
• Infects all cells including
microbial cells
• Contains nucleic acid
enclosed in a protein
coat-Capsid

7. Fungi
• Eukaryote
• Non-photosynthetic
• Exists in two
morphological forms:
– Yeast
– Mold

8. Yeasts
• Unicellular
• Shape - round to oval
• Size – 3-4 um
• Reproduce asexually
by mitosis (Budding)
– Saccharomyces cerevisiae
– Candida albicans

9. Molds
• Fungi that grows in the form
of multicellular filaments
called hyphae
• Forms a mass of branching
intercalating hyphae known
as a mycelium.
– Penicillium notatum
– Rhizopus sps
– Mucor sps
– Aspergillus fumigatus

10. Protozoa
• Unicellular
nonphotosynthetic
– Flagellelates
– Amoeboid
– Sporozoans
– Ciliates
• Causes-Giardiasis,
Amoebiasis, Malaria,
Leishmaniasis,
Toxoplasmosis, etc.

11. Helminthes
• Eukaryotes
• Worm-like organisms living
in and feeding on
living host
– Round worm
– Whipworm
– Hookworms

12. Prions
• An infectious agent composed
of protein in a misfolded form.
• Proteinaceous infectious
particles.
• PrPc  PrPsc
• Affects the structure of
the brain and neural tissues
that are currently untreatable
and universally fatal
Diseases:
• Kuru
• Creuzfeldt-Jacob disease

13. Historical perspective
• Antony Van Leeuwenhoek
• Ducth merchant (1683)
• First to observe and
describe bacteria.
• “Animalcules”

14. Louis Pasteur (1822-1895)
• French chemist
• Father of modern microbiology
• Disproved theory of spontaneous generation
• Developed methods and techniques of
cultivation of microorganisms.
• Studies on pebrine (silkmworm disease),
anthrax, chicken cholera and hydrophobia.
• Attenuated Live vaccines.

15. Joseph Lister (1867)
• Professor of surgery
• Introduced antiseptic technique in
surgery
• Used Carbolic acid to kill bacteria
in wounds
• Father of antiseptic surgery

16. Robert Koch (1843-1910)
• German General practitioner
• Introduced methods for isolation of
pure strains of bacteria.
• Used agar as a setting agent in
culture media.
• Isolated anthrax bacilli in pure
culture.
• “Father of Medical microbiology”
• Koch’s postulates

17. Koch’s Postulates
• The organism must be regularly associated
with the disease and its characteristic lesions.
• The organism must be isolated from the
diseased host and grown in pure culture.
• The disease must be reproduced when a pure
culture of the organism is introduced into a
healthy, susceptible host.
• The same organism must be reisolated from
the experimentally infected host.

19. THANK YOU!!