• As with anything you choose to do well, success in this class will require a significant input of time and thought on your part – 4 to 8 hours a week plus class and lab time. Please do not assume listening to me during lecture and cramming for the tests will be sufficient.

 

• Read the chapter before each lecture (do not read in depth, note the headings and the words written in bold. Attendance is mandatory for success. Listen, ask questions, and take notes. Go over your notes and re-read portions of the chapter as quickly after class as possible. Focus only on the areas covered by the notes (slides). Go over the figures in the book (slides). Memorize any terms and words you were not familiar with. Make an outline, answer questions in the book (both in chapters and at the end of each chapter), and explain each concept or term to a friend/enemy. Then read the section we will be covering for the next lecture. If you do not understand something, come to my office and ask for help immediately, not the day before the test!! If you can not come during my office hours please make an appointment to see me. For each test review the slides, terms, and your outline. Tutor a friend, explain concepts and test each other.

• Grading policies:

• Tests can include fill in the blanks, true and false, short answers, essay, multiple choice… and vary widely from test to test.

• Questions often require that you use your knowledge to answer questions on subjects we did not specifically cover in class. This requires that you understand the material.

• If you miss a test, you must make arrangements to take that test within a week. If you miss two, 5 % will be subtracted from your test score. If you miss three tests, 10% will be subtracted. Attendance is mandatory for success

• Grading is not curved.

• 90-100% = A

• 80-89% = B

• 70-79% = C

• 60-69% = D

• 50-59% = F

• Lab is 25% of your grade.

• Each day before or after lecture, a quiz may be given covering the lectures before. These quizzes will be as much as 20% of your grade. Therefore, go over your notes and re-read portions of the chapter as quickly after class as possible. Focus only on the areas covered by the notes (slides). Go over the figures in the book (slides). Memorize any terms and words you were not familiar with. Make an outline, answer questions in the book (both in chapters and at the end of each chapter), and explain each concept or term to a friend/enemy.

• Use the web site for useful chapter outlines, quizzes, etc: www.wiley.com/college/black/.

• Do the questions at the end of the chapter. The deadline will always be one class period after we finish the chapter.

• Importance of Microbiology– Microorganisms are almost everywhere, they are part

of the human environment and are important to human health

• are essential to the web of life– capture energy from sunlight

– decompose dead organisms

– make nitrogen available to plants

– essential links in food chains

» digestive tracts of grazing animals - aid in digestive processes

– essential in food industry

» pickles, yogurt, etc.

– synthesize antibiotics

– tools for genetic engineering - produce insulin etc.

– degrade oil spills, etc.

• Importance of Microbiology– are essential to the web of life– provide insight into life processes in all life forms

• useful in research– because they are relatively simple– reproduce rapidly– large numbers can be used to obtain statistically reliable results

• useful in research– how matter is decomposed– metabolic pathways– how hereditary information is transferred

– some cause disease in humans, animals, and plants• learn how diseases are transmitted, diagnosed, and prevented• vaccines have nearly eradicated several dreded childhood

diseases - measles, polio, etc.

Microbiologists study 5 major groups of organisms:bacteria (prokaryotes), (eukaryotes) algae, fungi, protozoa, and viruses (acellular*).Most microbes studied are unicellular*. They range from viruses at 20nm to large protozoans at 5mm or more in diameter (250,000 Xs as large).

*Cells are the basic units of structure and function of all living things.

Bacteria are prokaryotes. They have no membrane bound organelles - no nucleus. Bacteria come in all shapes, mainly rods, spheres, and spiral shapes. These are rod shaped bacterium that can cause pneumonia in humans. Pg7.

Algae, fungi, and protozoa are eukaryotes. They are larger and more complex than bacteria. They contain membrane bound organelles, including a nucleus.

Algae can be single-celled or relatively large and complex multicellular organisms. All algae photosynthesize their own food, as plants do. Only one species causes disease in humans

Fungi such as yeasts and some molds are single-celled. However, others such as mushrooms are multicellular macroscopic organisms. Fungi are eukaryotic, with membrane-bound organelles. All fungi absorb ready-made nutrients from their environment. They decompose dead organisms. Some cause disease or are sources of antibiotics.

These are fruiting bodies of a fungus with black spore packets on top that will be shot into the air to colonize new areas.

Viruses are acellular, made up of a nucleic acid and a few proteins. They replicate in cells and can cause disease. These are bacteriophage, viruses that invade bacteria.

Protozoa are single-celled, microscopic eukaryotic organisms. Most ingest smaller microorganisms and most can move. Some protozoa cause human disease - malaria

Also covered are helminths (worms) and arthropods (insects) since helminths have microscopic states in their life cycles which can cause disease and insects transmit these stages as well as other microbes.

This is an amoeba.

• Naming bacteria– two names: their genus and species names

• Escherichia coli (E. coli)- lives in your gut

• Giardia intestinalis - causes severe diarrhea

• Naming viruses– named for the group - herpesviruses

– named for the disease they cause - polioviruses

• Table 1.1– know 5 bacterial diseases and five viral diseases.

• CDC = Centers for Disease Control and Prevention, a federal agency that collects data about diseases and ways to control them.

• Fields of Microbiology

– organisms studies• bacteriology bacteria protozoology protozoa

• phycology algae parasitology parasites

• mycology fungi virology viruses

– processes or functions studied• microbial metabolism-chemical reactions occuring in microbes

• microbial genetics-transmission of genetic information

• microbial ecology-relationships with each other & the environment

– health-related fields• immunology-how host organisms defend against infection

• epidemiology-frequency and distribution of diseases

• etiology-causes of disease

• infection control

• chemotherapy

– applications• food and beverage protection, environmental-safe drinking water, etc.

Table 1-2

See checklist page 10

The first person to observe and describe microorganisms accurately was Antony van Leeuwenhoek.

Eventually led to the cell theory which states that cells are the fundamental units of life and carry out all the basic functions of living things.

Spontaneous generation

• Believed from earliest times, that living organisms could develop from nonliving matter.

• As long as scientists believed microorganisms could arise from nonliving substances, they did not consider how diseases were transmitted or how they could be controlled.

• Disproving this belief was necessary and as with all long held beliefs, it took a long time.

Fig. 1-6

Disproved for macro-organisms by Redi

He placed meat in three containers, one uncovered, one covered with paper, and one covered with a fine gauze (allowing air in but not flies). Maggots developed on the meat only in the uncovered container. They developed on the gauze, but not on the meat. Showing that the eggs came from flies, and maggots do not spontaneously appear.

Pastuer placed nutrient solutions in flasks, heated and bent their necks into curves while keeping the ends open to the atmosphere. (Some thought “air” or the “life force” in air was needed for spontaneous generation.) No bacterial growth

Disproved by Pasteur for microorganisms

Other experiments had been done to disprove spontaneous generation of microbes, but many still argued that altering the air prevented of

microorganisms

Air and microbes entered the curved tubes, but microbes were trapped in the curves of the neck and never reached the broth.

• Germ theory of disease states that microorganisms can invade other organisms and cause disease.

• Pasteur’s work in the wine and silk industry demonstrated that certain microorganisms caused disease. Pasteur also developed a rabies vaccine.

• Lister develops antiseptic surgery which prevents infection– heat sterilized instruments and phenol on surgical dressings

• Koch proposes criteria to establish relationship between microbe and disease - Koch’s postulates– 1. The microorganism must be present in every case of disease (and

absent from healthy organisms)

– 2. The suspected microorganisms must be isolated and grown in pure culture (see next slide)

– 3. The same disease must result when it is inoculated into a healthy host.

– 4. The same microorganism must be isolated again from the diseased host.

• Early techniques for studying microbial pathogens introduced by Koch include– agar as a solidifying agent on which to grow the microbes– Media suitable for growing bacteria, meat extracts and protein

digests lead to nutrient broth and nutrient agar used today• Solid media allows for isolation of pure colonies, important in the

study of microbes and the determination of pathogenicity. See box on page 16 “last drop”.

See checklist page 17

• Special Fields of Microbiology Table 1.2– Immunology is the study of the host’s responses to

protect against microbial invasion.• Vaccination was the first step in recognizing that the host

immune system “did something” to protect from and remember a pathogen.

– Chinese knew that a person who survived smallpox was protected. They ground up dried scabs and inhaled the weakened organisms to protect themselves from smallpox.

– Jenner realized that milkmaids got cowpox (milder than small pox) but they did not get smallpox, they were protected. He inoculated an 8 year old with cowpox, then later with small pox (!!!). The boy did not get sick (lucky for Jenner)

– Pasteur also worked on vaccines, especially known for rabies. He reasoned that the microbes had lost their ability to induce disease, but retained their ability to induce immunity.

• Phagocytes = cells that “eat” other cells or parts of cells. Metchnikoff discovered that phagocytes are important in protection against infection. See box on page 18.

Fig. 1-13

•Special Fields of Microbiology Table 1.2•Virology

•Once a porcelain filter was developed to remove bacteria from water etc, it was found that some infectious agents could get through the filter. These were found to be viruses.•Viruses consist of protein and nucleic acid (RNA or DNA) and can replicate and “live” only in host cells, using the cells chemical machinary.

Development of techniques for isolating, growing, and analyzing viruses has led to the isolation and characterizationof many viruses. Some have been crystallized. Viruses can be seen using an electron microscope.

See Box on page 18 - mosquitoes

Tobacco mosaic virus

• Special Field of Microbiology– Chemotherapy

• Substances derived from plants - digitalis, ephedrine, morphine - have been used by cultures like Native Americans

• Ehrlich recognized that certain dyes stained microbes and not animal cells, suggesting that dyes or other chemicals might selectively kill microbes. Began systematic search

• Other substances made by the body itself, lysozyme in tears, were discovered

– Antibiotics = substances that kill bacteria and are made by bacteria or mold (Penicillium) - Fleming

• Difficult to purify in sufficient quantities until WWII

• Searched soil samples for growth-inhibiting microorganisms or their products. Still today.

• Special Field of Microbiology– Genetics and Molecular Biology

• Most of the key discoveries that led to our present understanding of genetics emerged from research with microbes

• genetic engineering converts bacteria into factories that produce drugs, hormones, vaccines, etc.

• Microbes, viruses in particular, are often used to insert new genes into other organisms, even into human cells

– ex. Immune deficiency corrected in a 4 yr old girl. Normal copy of the mutated gene was inserted into some of here white blood cells in the laboratory and then the treated cells were injected back into her body. These cells then restored her immune system.

• Microbial genetic techniques have made possible the Human Genome Project, finished ahead of schedule, May 2000.

The scientific method

Box on page 21

How Microbiologists Investigate Problems

observations

Do the questions in the back of the chapter. Deadline for handing them in will always be one class period after we are finished with the chapter. Correct them yourself first.