burton's microbiology ch1

PowerPoint® Lecture Slide Presentation prepared by Mignonette S. Hipolito, CAS-BIO

F O R T H E H E A L T H S C I E N C E SE I G H T H E D I T I O N

B U R T O N ’ S

CHAPTER 1 MICROBIOLOGY: THE SCIENCE

• Microorganisms • are organisms that are too small to be seen with the

unaided eye.

• some are friends others are foes

• affect our daily lives and our environment

• knowledge of them is important to healthcare professionals

INTRODUCTION

• Micro – very small + Biology – study of living organisms

• Microbiology – study of very small living organisms called microorganisms or microbes

• Microorganisms – are virtually everywhere; viewed under a microscope

What is Microbiology?

Categories of Microorganisms

• Viruses

• Bacteria

• Archaeans

• Algae

• Protozoa

• Fungi

• Prokaryotes

• Peptidoglycan cell walls

• Binary fission

• For energy, use organic chemicals, inorganic chemicals, or photosynthesis

Bacteria

Figure 1.1a

• Prokaryotic

• Lack peptidoglycan

• Live in extreme environments

• Include:

• Methanogens

• Extreme halophiles

• Extreme thermophiles

Archaea:

Figure 4.5b

• Eukaryotes

• Chitin cell walls

• Use organic chemicals for energy

• Molds and mushrooms are multicellular consisting of masses of mycelia, which are composed of filaments called hyphae

• Yeasts are unicellular

Figure 1.1b

• Eukaryotes

• Absorb or ingest organic chemicals

• May be motile via pseudopods, cilia, or flagella

Protozoa

Figure 1.1c

• Eukaryotes

• Cellulose cell walls

• Use photosynthesis for energy

• Produce molecular oxygen and organic compounds

Figure 1.1d

• Acellular

• Consist of DNA or RNA core

• Core is surrounded by a protein coat

• Coat may be enclosed in a lipid envelope

• Viruses are replicated only when they are in a living host cell

Viruses

Figure 1.1e

• Eukaryote

• Multicellular animals

• Parasitic flatworms and round worms are called helminths.

• Microscopic stages in life cycles.

Multicellular Animal Parasites

Figure 12.28

Germs. Although not a scientific term, “germs” are the microorganisms that cause disease

Pathogens – disease-causing microorganism

Nonpathogens – do not cause disease

Why Study Microbiology?

• Indigenous microflora or microbiota – are beneficial; inhibit growth of pathogens by occupying space• 10X the total # of our cells

• 500 -1,000 diff spp.

• Opportunistic pathogens (opportunists) – do not usually cause problems, but have potential to cause infection (e.g. Escherichia coli)

Areas of the body where most of the indigenous microbiota reside

• Normal microbiota prevent growth of pathogens.• Normal microbiota produce growth factors such

as folic acid and vitamin K.

Did you know? (Tortora, 8th ed.)

• Bacteria were once classified as plants which gave rise to use of the term flora for microbes.

• This term has been replaced by microbiota.

• Microbes normally present in and on the human body are called normal microbiota.

Why Study Microbiology? (cont.)

• Decomposers or saprophytes• Decompose organic waste

• Saprophytes –live on dead or decaying matter

• Aid in fertilization, returns inorganic nutrients to the soil

Nitrogen Fixation. N-fixing bacteria (on or near roots of legumes) convert free N from the air to NH4 in the soil. Nitrifying bacteria then convert the ammonia into nitrites and nitrates, which are nutrients used by plants

• Microbial Ecology – study of relationships bet microbes and the environment

• Bacteria recycle carbon, nutrients, sulfur, and phosphorus that can be used by plants and animals.

• Food chain. Tiny living organisms such as bacteria, algae, microscopic aquatic plants (e.g. phytoplankton), and microscopic aquatic animals (e.g. zooplankton) are eaten by larger animals, which in turn are eaten by still larger animals, etc., until an

animal in the chain is consumed by a human.

• Humans are at the top of the food chain.

Why Study Microbiology? (cont.)• Some microorganisms live in intestinal tracts of animals

• E. coli bacteria produce Vit.K and B1

• Termites have cellulose-eating protozoa

• Produce products used in manufacturing (e.g., cellulase) and treatment (e.g., insulin, antibiotics)

antibiotics- substance produced by a microorganism, effective in killing or inhibiting growth of other microorganisms

• Produce industrial chemicals such as ethyl alcohol and acetone

• Produce fermented foods such as vinegar, cheesecheese, and bread

Biotechnology – use of microorganisms in industry

• Bioremediation

• Bacteria degrade organic matter in sewage.

• Bacteria degrade or detoxify pollutants such as oil and mercury

• Genetic engineering is a new techniquee for biotechnology.

• Missing or defective genes in human cells can be replaced in gene therapy.

• Genetically modified bacteria are used to protect crops from insects and freezing.

• Microorganisms cause 2 categories of diseases:

• Infectious disease – pathogen colonizes body and subsequently causes disease

• Microbial intoxication – when a person ingests toxin (poisonous substance) produced by a microorganism

Two categories of diseases caused by pathogens.

• Allows humans to

• Prevent food spoilage

• Prevent disease occurrence

Thus, knowledge of microorganisms:

• Led to aseptic techniques to prevent contamination in medicine and in microbiology laboratories.

First Microorganisms on Earth

• Fossils of primitive microorganisms 3.5B yrs ago (as many as 11 diff types) found in ancient rock formations in NW Australia

• Archaeans and Cyanobacteria – candidates for the first microorganisms on earth

Earliest Known Infectious Diseases• 3180 BC – Egypt, the terms “pestilence” and

“plague”

• 1900 BC – near the end of Trojan War, Greek army decimated by supposed bubonic plague

• 1500 BC - Ebers papyrus :epidemic fevers in a tomb in Thebes Egypt

• 1122 BC – China, “smallpox”

• 790, 710, 640 BC – Epidemics of plague in Rome

• 430 BC – Epidemics of plague in Greece

Pioneers in the Science of Microbiology

Anton van Leeuwenhoek (1632 – 1723)

• First person to see live bacteria and protozoa• Described live microorganisms that he observed in teeth scrapings, rain water, and peppercorn infusions.

Louis Pasteur (1822 – 1895)

• French chemist

• Made many significant contributions

• Fermentation process

• Disproved Theory of Spontaneous Generation

• “Aerobes” and “Anaerobes”

• Pasteurization

• Silkworm disease

• Germ Theory of disease

• Changes in hospital practices

• Vaccines

• Pasteur’s S-shaped flask kept microbes out but let air in.

The Theory of Biogenesis

Figure 1.3

Robert Koch (1843 – 1910)

• German physician

• Germ theory of disease

• Koch’s Postulates

• Methods of fixing, staining and photographing bacteria

• Methods of bacterial culture (with J.R. Petri and Frau Hess)

• Mycobacterium tuberculosis and Vibrio cholerae

• Tuberculin protein- used in TB skin test

Koch’s Postulates

• Exceptions:• Obligate intracellular

pathogens (viruses, rickettsias and chlamydias)

• Fastidious microorganisms

• Species-specific pathogens

• Synergistic infection (ex. ANUG and bacterial vaginosis)

• Effects of in vitro culture

• Not all diseases are caused by microorganisms

Careers in Microbiology

• Bacteriology

• Phycology

• Protozoology

• Mycology

• Virology

Naming and Classifying Microorganisms

• Linnaeus established the system of scientific nomenclature.

• Each organism has two names: the genus and specific epithet.

• Are italicized or underlined. The genus is capitalized and the specific epithet is lower case.

• Are “Latinized” and used worldwide.

• May be descriptive or honor a scientist.

Scientific names

• Staphylococcus aureus

• Describes the clustered arrangement of the cells (staphylo-) and the golden color of the colonies.

Scientific names

• Escherichia coli

• Honors the discoverer, Theodor Eshcerich, and describes the bacterium’s habitat, the large intestine or colon.

Scientific names

• After the first use, scientific names may be abbreviated with the first letter of the genus and the specific epithet:

• Staphylococcus aureus and Esherichia coli are found in the human body. S. aureus is on skin and E. coli, in the large intestine.

Scientific names

Finish….. Quiz Next Meeting!!

burton's microbiology ch1

Documents

microbiology poster presentation

ghesini silvia microbiology

microbiology lecture 2

colomer ch1

microbiology lab 2

ch1 introduction

introductory microbiology mcb2000

lecture-2 principles of...

ch1 page 2 - anurita dhiman's lec website...ch1 page 2 . ch1...

microbiology products us catalog · 2016 - 2017...

microbiology lab 1

42474899 microbiology

microbiologia / microbiology

environmental microbiology

jig's microbiology

oral microbiology seminar1

microbiology microbial metabolism i -...

standard klinic microbiology

microbiology & immunology department specification...

microbiology chapter 16