Introduction to microbiology

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Introduction to microbiology

• Biology II
• Mrs. Hieneman

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Definition of Microbiology

• the study of those organisms best observed with
  the aid of a microscope.
• employs techniques and procedures required to
  study microorganisms.

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Fields of microbiology

• Bacteriology prokaryotic cells
• Virology viruses
• Mycology fungi
• Protozoology protozoans (single celled
  prokaryotes)
• Parasitology parasites
• Immunology
• Medical Microbiology
• Microbial Genetics
• Microbial Ecology
• Biotechnology

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Anthon van Leeuwenhoek

• (1632 1723)
• Dry goods merchant
• Lens grinder
• Produced simple (single lens) microscopes
• In report dated Oct 9 1676 is the first
  description of bacteria.

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Louis pasteur

• (1822 1895)
• Frenchman trained as a chemist.
• Discovered isomers of tartaric acid.
• Discovered the process of fermentation and
  developed a method of pasteurization to reduce
  microbial contamination of wine and beer.
• Developed anthrax and rabies vaccines.

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What CAUSED DISEASE?

• Humoral theory an imbalance of the four body
  humors (black bile, yellow bile, phlegm, blood)
  resulted in disease. Treatments bloodletting,
  expectorants, purgatives.
• Demonic theory cast out the demons exorcists
  conducted this practice.
• Miasmatic theory something in the air (miasma
  poisonous vapor) malaria bad air influenza
  influence of the stars.
• Germ theory particulate matter transmissible
  from one person to another initiated disease.

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Germ Theory of Disease

• Agostino Bassi
• Silkworm disease caused by a fungus (1835)
• Ignaz Semmelweis
• Invisible agent caused sepsis (1841)
• M.J. Berkeley
• Potato blight of Ireland caused by a fungus
  (1857)
• Joseph Lister
• Introduced concept of sterile surgical field
• Use of antiseptics followed
• Developed limiting dilution technique

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Robert Koch (1843 1910)

• German physician (and Pasteurs rival)
• Studied the disease anthrax
• Developed a method to identify the etiologic
  agent.
• First utilized to identify Bacillus anthracis as
  etiologic agent of anthrax (1877)
• Developed a set of postulates

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Kochs postulates

• The microorganism must be present in the diseased
  host, and absent for the healthy.
• Microbe must be isolated and grown in a pure
  culture.
• Isolated microbe must cause disease when
  inoculated into healthy laboratory host.
• Must re-isolate the microbe from the diseased
  laboratory host.

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Bacillus anthracis

• Large, aerobic, non-motile, gram positive,
  spore-forming rod.
• Easily cultured on ordinary medium.
• Spores can be found in soil world wide.
• Affects humans and livestock
• Can be transferred from animals to humans.

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anthrax
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Anthrax

• Iran 1945 outbreak killed 1 million sheep.
• Russia 1979 accidental release of spores
  infected 79, killed 68 (inhalational anthrax)
• Easily weaponized to produce a biological warfare
  agent.
• Bioterror attack through U.S. Postal Service on
  East Coast Oct. 2001 23 cases.
• 17 nations believed to have biological warfare
  programs

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anthrax

• Incubation Period (Time from initial infection
  to appearance of symptoms) 1-7 days to a few
  weeks.
• Symptoms onset of abrupt fever and chest pain,
  lethargy, progressing rapidly to a hemorrhagic
  pathology.
• NOT contagious from person to person
• THREE forms
• Inhalational, cutaneous, gastrointestinal

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Cutaneous

• Cutaneous anthrax usually occurs when spores from
  the bacteria enter a cut or scrape on the skin.
  Cutaneous anthrax infection has the following
  characteristics
• Skin infection begins as a small, raised bump
  that might itch-similar to an insect or spider
  bite.
• Within 1 to 2 days, the bump develops into a
  fluid-filled blister about 1cm to 3cm in
  diameter. Within 7 to 10 days, the blister
  usually has a black center of dying tissue
  (eschar) surrounded by redness and swelling. The
  blister is usually painless.
• Additional blisters may develop.
• Other symptoms may include
• Swollen lymph nodes close to the area of the
  blister.
• Fever.
• Headache.
• A general feeling of discomfort.

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Inhalational

• The most lethal form of exposure occurs from
  inhalational anthrax . The incubation period for
  this form of anthrax may be 60 days or more,
  although it is usually 2 to 3 days. Initial
  symptoms can include
• Sore throat.
• Mild fever.
• Muscle aches.
• Symptoms can progress rapidly after just a few
  days to include
• Severe difficulty with breathing.
• Shock, which can develop rapidly.
• Meningitis, which develops frequently.
• Death can occur within 24 to 36 hours after such
  complications occur. Respiratory symptoms may be
  similar to those of pneumonia.

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Gastrointestinal

• No confirmed cases of gastrointestinal anthrax
  have been reported in the United States.2 This
  form of anthrax occurs after eating meat
  contaminated with the bacteria that cause
  anthrax. Gastrointestinal anthrax can be more
  serious than cutaneous anthrax but can be treated
  effectively with prompt use of antibiotics. But
  if untreated, gastrointestinal anthrax causes
• Ulcers at the base of the tongue or tonsils.
• Sore throat.
• Loss of appetite.
• Vomiting.
• Fever.
• These symptoms are followed by
• Abdominal pain.
• Vomiting of blood.
• Bloody diarrhea.
• Within 2 to 4 days after these symptoms develop,
  fluid (ascites) fills the abdomen shock and
  death usually follow within 2 to 5 days.