Pathogenic Microbiology

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Pathogenic Microbiology

• Please copy the following basic definitions that
  will be used to describe the germs that make us
  sick
• Infection The colonization of a host organism
  by a harmful species.
• Pathogen An organism responsible for causing a
  disease
• Infectious Disease a branch of medicine dealing
  with pathogens and their diseases

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The Germ Theory of Disease

• This old, dead, white dude named Robert Koch
  developed scientific proof that specific
  microorganisms cause specific diseases in 1890

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Kochs Postulates

• This is how a specific organism can be proven to
  be the causative agent of a specific disease.
• Isolate and identify organism from sick host
• The isolated organism causes the same illness if
  given to a new host, and can be isolated from the
  second host once again.

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Types of Pathogens

• Infectious diseases may be caused by bacteria,
  viruses, eukaryotes, and other agents.
• There are an amazing number of different
  pathogenic species, and they can make you sick in
  a variety of ways.

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Top 10 Infectious Diseases 2002
1 Lower respiratory infections12 3.9 million 6.9 (pnemonia, influenza, etc.)
2 HIV/AIDS 2.8 million 4.9
3 Diarrheal diseases13 1.8 million 3.2
4 Tuberculosis (TB) 1.6 million 2.7
5 Malaria 1.3 million 2.2
6 Measles 0.6 million 1.1
7 Pertussis 0.29 million 0.5
8 Tetanus 0.21 million 0.4
9 Meningitis 0.17 million 0.3
10 Syphilis 0.16 million 0.3
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Viruses

• A virus is a tiny (10-300 nm) infectious agent.
  Viruses are not cells.
• Most viruses have only a few genes (flu has 10.
  you have gt30,000)
• Viruses cause disease by entering host cells,
  reproducing, and then causing the cell to burst.

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The size of things Eukaryote v. prokaryote
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The Size of Things Prokaryote v. Virus
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Viral Replication Ribosome Hijacking

• All viruses are pathogens they cannot reproduce
  by themselves

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Common Viral Diseases

• Common Cold
• Influenza
• Chickenpox
• Herpes
• Hepatitis
• HIV
• Many, many others

Chickenpox
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Do Now

• Make a list of the specific information you
  should include in the abstract section of the
  upcoming Winogradsky column lab report.
• I. Abstract. The abstract of your report should
  quickly describe your experiment, its
  significance, and its results. It will include 3
  parts
• A. Background information about the topic,
  including basic information about processes,
  organisms, or other principles underlying the
  experiment.
• B. A description of your experiment, including
  the hypothesis and predictions underlying your
  experiment. To put it shortly, explain what you
  expected to find, how you expected to find it,
  and why you expected what you did.
• C. A summary of your results. What did you
  find out?

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M M

• This section should be a detailed account of what
  it is you did, the equipment you used, and all of
  the procedures you followed. Someone following
  your materials methods should b able to
  perfectly repeat your experiment and produce the
  same results. Be detailed!

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Data Results

• This section will include all of your
  observations, measurements, data, graphs, charts,
  calculations, and any other data or analysis you
  perform.

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Conclusion

• What did you discover, prove, or see an example
  of? How do you know? Did anything go wrong?
  How could the experiment be improved? Why are
  your findings important? What biological concept
  has your experiment demonstrated?

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Bacteria

• Most bacteria are noninfectious
• Some are opportunistic pathogens cause illness
  in weak and sick individuals.
• Others are obligate pathogens always cause
  disease to survive

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How Bacteria Cause Illness

• Most bacterial diseases are caused by toxic
  chemicals called exotoxins or endotoxins that the
  bacteria produce. These toxins can disrupt or
  destroy nearby cells

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Bacterial Diseases

• Leprosy
• Tetanus
• Whooping Cough
• Typhoid Fever
• Cholera
• Plague
• Tuberculosis
• Meningitis
• Bacterial Pneumonia
• Anthrax
• Botulism
• Bacterial Dysentry
• Diarrhoea
• Food Poisoning
• Gas Gangrene
• Syphilis
• Diphtheria
• Gonorrhoea
• Typhus Fever

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Protists Fungi

• Eukaryotes can be pathogenic too!
• Unicellular parasites can live within cells and
  tissues, causing diseases such as
• Toxoplasmosis
• amoebic meningitis
• Malaria
• Trypanosmiasis
• Leishmaniasis
• amoebic dysentery
• diarrhoea caused by Cryptosporidium spp. or
  Giardia intestinalis (lamblia)

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Worms

• Roundworms and flatworms are two major classes of
  multicellular human pathogens but well learn
  more about them in the future.

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Other Stuff

• Still other diseases like Mad Cow Disease are
  caused by prions.
• A prion is an infectious agent that is a single
  protein molecule