MCB4203 Exam 1 Latest Update
Know the three types of Yersinia pestis infections. - Answer Causes plagues
Bubonic (up to 80% death rate)
septicaemic (~100% death rate)
pneumonic (~95% death rate) plague
Know how the trade and changing environments brought Yersinia pestis into Europe. -
Answer Climate change in Asia -> rodents with infected fleas moved to populated areas
Aftermath:
• Malnutrition
• Poverty
• Wars
• Price control on grain and exported goods • Inflation
• Population reduction
• Deforestation leading to likely climate change
• Religious persecution
Know the difference between prokaryotes and eukaryotes - Answer Eukaryotes
(multicellular organisms): fungi, protozoa
Prokaryotes (single-celled): bacteria and archaea
Know who first coined the term cells - Answer Robert Hooke
has not seen single-celled organisms but used this term
First description of microorganisms
Know who made their own microscopes and examined single-celled organisms - Answer
Antonie van Leewenhoek
examined water and visualized fungi, algae, and single-celled protozoa "animalcules"
Know the four questions scientists sought to answer (slide 11) - Answer 1. Is
spontaneous generation of microbial life possible?
2. What causes fermentation?
3. What causes disease?
,4. How can we prevent infection and disease?
Know who setup the "meat-jar" experiment to disprove spontaneous generation -
Answer Francesco Redi designed experiment to test the spontaneous creation of
maggots by placing meat in sealed/unsealed jars
....maggots do not spontaneously arise from decaying meat -> animals can not arise
spontaneously
Know John Needham's and Lazzaro Spallanzani's experiments - Answer John Needham
experiments reinforced the idea of spontaneous regeneration (~1745)
Lazzaro Spallanzani (~1765) refuted this claim: - Needham failed to heat vials sufficiently
to kill all microbes or had not sealed vials tightly enough - Microorganisms exist in air
and can contaminate experiments - Spontaneous generation of microorganisms does
not occur
Critics: vials did not allow enough air for organisms to survive and that prolonged
heating destroyed "life force
Know the Three Founders of Bacteriology and their importance - Answer Ferdinand
Cohn (1828-1898): father of modern bacteriology
Robert Koch (1843-1910):
German physician
- studied causative agents of disease (anthrax, cholera, TB)
- Isolated and grown Anthrax bacillus can be transmitted to other cattle
- invented methods of selectively growing organisms in pure culture
- pick a colony
- Koch's postulates must be satisfied before we agree that specific bacteria cause
particular disease
- Nobel Prize - 1905
Louis Pasteur (1822-1895):
- Worked on issues faced by French wine makers (fermentation to acetic acid instead of
alcohol by bacteria-contaminated yeast cultures)
- His research challenged 'spontaneous generation' claims
- Germ theory, vaccination (chicken cholera)
Know Koch's Postulates and be able to describe/define them - Answer The Germ Theory
of disease:
,1876: Koch provided proof that a bacterium causes anthrax and provided the
experimental steps (Koch's postulates) used to prove that a specific microbe causes a
specific disease. Koch's Postulates are a sequence of experimental steps to relate a
specific microbe to a specific disease.
Know Carl Linnaeus and his work - Answer Carl Linnaeus (1707-1778) developed
taxonomic system for naming plants and animals and grouping similar organisms
together
• Leeuwenhoek's microorganisms were grouped into six categories:
• Fungi
• Protozoa
• Algae
• Bacteria
• Archaea
• Small animals
Bacteria! - Answer Bacteria are formidable opponents: first form of life on Earth 3.5-4
billions years ago
• Master recyclers: created first oxygen, making life on Earth possible
• Developed a whole spectrum of metabolic capabilities to survive in various conditions
(metabolize by oxidizing sulfides, reducing sulfate, oxidizing ammonia, reducing nitrate
etc.)
• Plasticity of genomes
• Found anywhere on earth
Bacteria's lives are intertwined with their hosts - Answer Bacterial endosymbionts
formed mitochondria and chloroplasts: function in respiration and regulation of
metabolism (mitochondria) as well as acquiring photosynthesis by plants (chloroplasts)
• Human and animals serve as rich niches for bacteria i.e. bacterial heaven
(temperature is stably maintained, lifestyle is to collect food and water). Human/animal
as a HOST
• Microbiome (microbial community) as our organ: microbes colonized intestinal tracts,
skin, mouth , vagina, and other parts of our body
• Helicobacter pylori: example of how sharing ancestral relationship with pathogen can
prevent ulcers and cancer. The longer human co-evolved with pathogen, the less likely
that bacterium caused diseases
, Know the difference between Gram-negative, Gram-positive, Mycobacteria, and
Mycoplasma. - Answer Gram-negative bacteria have plasma membrane and outer
membrane (separated by periplasm). These bacteria contain LPS (lipopolysaccharides).
Gram-positive bacteria have only plasma membrane, contain lipoteichoic acid (LTA)
Mycobacteria (acid-fast bacteria) resemble Gram-positive bacteria but contain also
glycolipids, such as mycolic acids
Mycoplasma has no cell wall
Know the basic structure of LPS - Answer LPS (lipopolysaccharides): "endotoxin"
present on Gramnegative bacteria:
Lipid A secures LPS in the OM responsible for the toxicity of Gram-negative bacteria ->
Septic shock
Parts:
1. Lipid A (endotoxin)
2. Core polysaccharide 3. O-antigen
Know why AMR is such a threat to the world and be able to describe it - Answer ~1970s:
danger of antibiotic resistance:
• Anti Microbial Resistance (AMR): ability of bacteria to resist the effects of antibiotics
• infections with such resistant bacteria are difficult to treat
• simply using antibiotics creates resistance
use of antibiotics in people and in food animals as a contributing factor to resistance
• Inappropriate and unnecessary use of antibiotics is a large contributing factor and it
should be limited
Know how "old" bacterial infections can reoccur. Be able to describe mutations and
their importance. - Answer "Apparently new diseases" emerge or "old disease"s can
reemerge:
• bacteria can acquire new traits via mutations and HGT
• our own activities create new opportunities for pathogens: a) Antibiotic use in
hospitals: AMR Clostridium difficile, Klebsiella pneumoniae, MRSA, Streptococcus
pneumoniae
b) Tuberculosis came back in 1990s (dismantled infrastructure to contain the spread,
presence of susceptible individual groups in prisons, emergence of AIDS)
Know the three types of Yersinia pestis infections. - Answer Causes plagues
Bubonic (up to 80% death rate)
septicaemic (~100% death rate)
pneumonic (~95% death rate) plague
Know how the trade and changing environments brought Yersinia pestis into Europe. -
Answer Climate change in Asia -> rodents with infected fleas moved to populated areas
Aftermath:
• Malnutrition
• Poverty
• Wars
• Price control on grain and exported goods • Inflation
• Population reduction
• Deforestation leading to likely climate change
• Religious persecution
Know the difference between prokaryotes and eukaryotes - Answer Eukaryotes
(multicellular organisms): fungi, protozoa
Prokaryotes (single-celled): bacteria and archaea
Know who first coined the term cells - Answer Robert Hooke
has not seen single-celled organisms but used this term
First description of microorganisms
Know who made their own microscopes and examined single-celled organisms - Answer
Antonie van Leewenhoek
examined water and visualized fungi, algae, and single-celled protozoa "animalcules"
Know the four questions scientists sought to answer (slide 11) - Answer 1. Is
spontaneous generation of microbial life possible?
2. What causes fermentation?
3. What causes disease?
,4. How can we prevent infection and disease?
Know who setup the "meat-jar" experiment to disprove spontaneous generation -
Answer Francesco Redi designed experiment to test the spontaneous creation of
maggots by placing meat in sealed/unsealed jars
....maggots do not spontaneously arise from decaying meat -> animals can not arise
spontaneously
Know John Needham's and Lazzaro Spallanzani's experiments - Answer John Needham
experiments reinforced the idea of spontaneous regeneration (~1745)
Lazzaro Spallanzani (~1765) refuted this claim: - Needham failed to heat vials sufficiently
to kill all microbes or had not sealed vials tightly enough - Microorganisms exist in air
and can contaminate experiments - Spontaneous generation of microorganisms does
not occur
Critics: vials did not allow enough air for organisms to survive and that prolonged
heating destroyed "life force
Know the Three Founders of Bacteriology and their importance - Answer Ferdinand
Cohn (1828-1898): father of modern bacteriology
Robert Koch (1843-1910):
German physician
- studied causative agents of disease (anthrax, cholera, TB)
- Isolated and grown Anthrax bacillus can be transmitted to other cattle
- invented methods of selectively growing organisms in pure culture
- pick a colony
- Koch's postulates must be satisfied before we agree that specific bacteria cause
particular disease
- Nobel Prize - 1905
Louis Pasteur (1822-1895):
- Worked on issues faced by French wine makers (fermentation to acetic acid instead of
alcohol by bacteria-contaminated yeast cultures)
- His research challenged 'spontaneous generation' claims
- Germ theory, vaccination (chicken cholera)
Know Koch's Postulates and be able to describe/define them - Answer The Germ Theory
of disease:
,1876: Koch provided proof that a bacterium causes anthrax and provided the
experimental steps (Koch's postulates) used to prove that a specific microbe causes a
specific disease. Koch's Postulates are a sequence of experimental steps to relate a
specific microbe to a specific disease.
Know Carl Linnaeus and his work - Answer Carl Linnaeus (1707-1778) developed
taxonomic system for naming plants and animals and grouping similar organisms
together
• Leeuwenhoek's microorganisms were grouped into six categories:
• Fungi
• Protozoa
• Algae
• Bacteria
• Archaea
• Small animals
Bacteria! - Answer Bacteria are formidable opponents: first form of life on Earth 3.5-4
billions years ago
• Master recyclers: created first oxygen, making life on Earth possible
• Developed a whole spectrum of metabolic capabilities to survive in various conditions
(metabolize by oxidizing sulfides, reducing sulfate, oxidizing ammonia, reducing nitrate
etc.)
• Plasticity of genomes
• Found anywhere on earth
Bacteria's lives are intertwined with their hosts - Answer Bacterial endosymbionts
formed mitochondria and chloroplasts: function in respiration and regulation of
metabolism (mitochondria) as well as acquiring photosynthesis by plants (chloroplasts)
• Human and animals serve as rich niches for bacteria i.e. bacterial heaven
(temperature is stably maintained, lifestyle is to collect food and water). Human/animal
as a HOST
• Microbiome (microbial community) as our organ: microbes colonized intestinal tracts,
skin, mouth , vagina, and other parts of our body
• Helicobacter pylori: example of how sharing ancestral relationship with pathogen can
prevent ulcers and cancer. The longer human co-evolved with pathogen, the less likely
that bacterium caused diseases
, Know the difference between Gram-negative, Gram-positive, Mycobacteria, and
Mycoplasma. - Answer Gram-negative bacteria have plasma membrane and outer
membrane (separated by periplasm). These bacteria contain LPS (lipopolysaccharides).
Gram-positive bacteria have only plasma membrane, contain lipoteichoic acid (LTA)
Mycobacteria (acid-fast bacteria) resemble Gram-positive bacteria but contain also
glycolipids, such as mycolic acids
Mycoplasma has no cell wall
Know the basic structure of LPS - Answer LPS (lipopolysaccharides): "endotoxin"
present on Gramnegative bacteria:
Lipid A secures LPS in the OM responsible for the toxicity of Gram-negative bacteria ->
Septic shock
Parts:
1. Lipid A (endotoxin)
2. Core polysaccharide 3. O-antigen
Know why AMR is such a threat to the world and be able to describe it - Answer ~1970s:
danger of antibiotic resistance:
• Anti Microbial Resistance (AMR): ability of bacteria to resist the effects of antibiotics
• infections with such resistant bacteria are difficult to treat
• simply using antibiotics creates resistance
use of antibiotics in people and in food animals as a contributing factor to resistance
• Inappropriate and unnecessary use of antibiotics is a large contributing factor and it
should be limited
Know how "old" bacterial infections can reoccur. Be able to describe mutations and
their importance. - Answer "Apparently new diseases" emerge or "old disease"s can
reemerge:
• bacteria can acquire new traits via mutations and HGT
• our own activities create new opportunities for pathogens: a) Antibiotic use in
hospitals: AMR Clostridium difficile, Klebsiella pneumoniae, MRSA, Streptococcus
pneumoniae
b) Tuberculosis came back in 1990s (dismantled infrastructure to contain the spread,
presence of susceptible individual groups in prisons, emergence of AIDS)
