introduction to medical microbiology basics

Introduction to Medical Microbiology

basicsDr.T.V.Rao MD

What is Microbiology?Microbes, or microorganisms are minute living things that are usually unable to be

viewed with the naked eye.

What are some examples of microbes?

Bacteria, fungi, protozoa, algae, viruses are examples!

Some are pathogenic

“Germ” refers to a rapidly growing cell.Dr.T.V.Rao MD 2

The Early Years of Microbiology contributed by The Early Years of Microbiology contributed by discovery of Microscope discovery of Microscope

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History of Microbiology1673-1723, Antoni van Leeuwenhoek (Dutch) described live microorganisms that he observed in teeth scrapings, rain water, and peppercorn infusions. Dr.T.V.Rao MD 4

Chapter 1 The Microbial World and You

History of Microbiology

The Golden Age of Microbiology 1857-1914

Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity, and antimicrobial drugs

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The Golden Age of Microbiology 1857-1914

Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity, and antimicrobial drugs

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MicrobiologyMicrobiology• The study of organisms too small to be seen

without magnification– bacteria– viruses– fungi– protozoa – Helminths (Parasites) – algae

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Branches of study within Microbiology

• Immunology

• Public health microbiology & epidemiology

• Food, dairy and aquatic microbiology

• Biotechnology

• Genetic engineering & recombinant DNA technology

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Microbes are involved in

• nutrient production & energy flow

• decomposition

• production of foods, drugs & vaccines

• bioremediation

• causing disease Dr.T.V.Rao MD

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Impact of pathogens

• Nearly 2,000 different microbes cause diseases

• 10 B infections/year worldwide

• 13 M deaths from infections/year worldwide

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Characteristics of microbes

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Antonie van Leeuwenhoek

• First to observe living microbes

• his single-lens magnified up to 300X

(1632-1723) Dr.T.V.Rao MD

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Scientific MethodScientific Method

• Form a hypothesis - a tentative explanation that can be supported or refuted by observation & experimentation

• A lengthy process of experimentation, analysis & testing either supports or refutes the hypothesis.

• Results must be published & repeated by other investigators.

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• If hypothesis is supported by a growing body of evidence & survives rigorous scrutiny, it moves to the next level of confidence - it becomes a theory

• Evidence of a theory is so compelling that the next level of confidence is reached - it becomes a Law or principle

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Spontaneous generation

Early belief that some forms of life could arise from vital forces present in

nonliving or decomposing matter.

(flies from manure, etc)

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Louis Pasteur

• Showed microbes caused fermentation & spoilage

• Disproved spontaneous generation of m.o.

• Developed aseptic techniques.

• Developed a rabies vaccine.

(1822-1895) Dr.T.V.Rao MD

Germ theory of disease

Many diseases are caused by the growth of microbes in the body and not by sins,

bad character, or poverty, etc.

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Robert KochRobert Koch

• Established a sequence of experimental steps to show that a specific m.o. causes a particular disease.

• Developed pure culture methods.

• Identified cause of anthrax, TB, & cholera.

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Taxonomy - Taxonomy - system for organizing, system for organizing, classifying & naming living thingsclassifying & naming living things

• Domain - Archaea, Bacteria & Eukarya• Kingdom - 5• Phylum or Division• Class • Order• Family• Genus• species

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Domains

• Eubacteria -true bacteria, peptidoglycan

• Archaea –odd bacteria that live in extreme environments, high salt, heat, etc

• Eukarya- have a nucleus, & organelles

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Naming Microorganisms

• Binomial (scientific) nomenclature • Gives each microbe 2 names

– Genus - noun, always capitalized– species - adjective, lowercase

• Both italicized or underlined– Staphylococcus aureus (S. aureus)– Bacillus subtilis (B. subtilis)– Escherichia coli (E. coli)

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Evolution- living things change gradually over millions of years

• Changes favoring survival are retained & less beneficial changes are lost.

• All new species originate from preexisting species.• Closely related organism have similar features

because they evolved from common ancestral forms.

• Evolution usually progresses toward greater complexity.

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• Program Created by Dr.T.V.Rao MD for Medical and Premedical students in the Emerging World

• Email

doctortvrao@gmail.com

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