Introduction to Microbiology and Disease Understanding

What is microbiology?

The study of microbes.

What are some expected learning outcomes for this microbiology course?

Describe and/or recognize early contributions to our understanding of disease and the contributions of key individuals in microbiology.

Name three individuals whose contributions to microbiology are recognized in the course.

Ferdinand Cohn, Louis Pasteur, Robert Koch.

What practices did ancient civilizations use to contain the spread of disease?

Isolation, quarantining, and hygiene/sanitation practices.

What does isolation refer to in the context of disease prevention?

Separation and confinement of individuals already known to be infected with a contagious disease.

What is the difference between isolation and quarantining?

Isolation refers to those already infected, while quarantining refers to those potentially exposed.

What disease is associated with the practice of isolation in the Bible?

Leprosy.

What is the causative agent of leprosy?

Mycobacterium leprae and Mycobacterium lepromatosis.

Is leprosy highly contagious?

No, it is not highly contagious and progresses slowly.

When was the modern concept of quarantining first implemented?

As early as the late 1300s.

What was required of ships coming from areas suspected of plague infection during the plague era?

Ships were required to remain docked for 30 days before allowing passengers to leave.

What is the purpose of quarantining in the context of infectious diseases?

Quarantining is used to help prevent the transmission and spread of infectious diseases.

Name three infectious diseases that have historically been prevented through quarantining practices.

Plague, cholera, Spanish influenza.

What theory suggested that diseases were caused by unhealthy vapors from the ground?

Miasma Theory.

How did the Ancient Romans contribute to sanitation and hygiene practices?

They built sewer systems to remove contaminated water and aqueducts to supply fresh water.

What is the Cloaca Maxima?

A sewer system built by the Romans that carried waste away from the city into the river Tiber.

What significant observation did Thucydides make regarding the Athenian Plague?

He observed that survivors did not get re-infected with the disease.

What concept did Thucydides' observation hint at?

An early understanding of immunity.

Who proposed the idea that unseen things can cause disease, and when was it published?

Marcus Terentius Varro proposed this idea in 36 BCE.

What did Robert Hooke develop that contributed to microbiology?

The first compound microscope.

What term did Robert Hooke coin from his observations of cork?

Cell.

What did Robert Hooke observe with his microscope besides cork?

Mold, insects, sponges, and bryozoans.

What was the impact of the Athenian Plague on the population of Athens between 430 and 410 BCE?

Nearly one-third of the population was killed.

What hygiene practices did the Ancient Greeks develop based on the Miasma Theory?

Frequent bathing, burning incense, and cleaning public spaces to ward off "bad air" believed to cause disease.

What does the term 'microorganisms' refer to in the context of disease causation?

Unseen entities that can cause disease.

What was the significance of the observation made by Thucydides during the Athenian Plague?

It indicated an early understanding of immunity.

What did the Romans build to improve public health and sanitation?

Sewer systems and aqueducts.

What was the main idea behind the Miasma Theory?

Diseases were produced by unhealthy or polluted vapors.

How did sanitation practices evolve in ancient civilizations?

They developed systems to remove waste and provide clean water.

What role did quarantine play in historical responses to infectious diseases?

It served as a preventive measure to control the spread of diseases.

What was a common practice for people traveling to infected areas during outbreaks?

They were often restricted from traveling to those areas.

Who is credited with the invention of the microscope that observed bacteria and protozoa?

Antonie van Leeuwenhoek

What term did Antonie van Leeuwenhoek use to describe the microbes he observed?

Animalcules

What was the magnification capability of Antonie van Leeuwenhoek's microscope?

Greater than 200x

What is the Petri dish used for?

Growing bacterial cultures

Who invented the Petri dish?

Julius Richard Petri

What significant contribution did Angelina Fanny Hesse make to microbiology?

Suggested the addition of agar to gelatin to solidify media at higher temperatures.

What techniques did Walther Hesse develop in the late 1800s?

New techniques for counting bacteria in air and water samples.

What process is John Tyndall known for developing?

Fractional sterilization (Tyndallization)

What did John Tyndall demonstrate about microbes?

Microbes are present in dust.

What contributions did Ferdinand Julius Cohn make to microbiology?

Classified bacteria based on morphology and distinguished between pathogenic and putrefactive bacteria.

What is Louis Pasteur known for?

Pasteurization, fermentation, and developing vaccines for anthrax and rabies.

How did Louis Pasteur contribute to disproving spontaneous generation?

His work supported the germ theory of disease.

What are Koch's Postulates?

Conditions that must be met to establish a specific microbe as the cause of a specific disease.

Which diseases did Robert Koch study using his postulates?

Anthrax, tuberculosis, and cholera.

What are the four main principles of Pasteur's germ theory?

1. Air contains living microorganisms. 2. Microbes are not evenly distributed in the air. 3. Microbes cause decay. 4. Microbes can be killed by heating.

What was the theory of spontaneous generation?

The belief that living organisms could arise from non-living matter.

How was spontaneous generation supported for so long?

It was widely accepted before experimental evidence disproved it.

Who ultimately disproved spontaneous generation?

Louis Pasteur.

What is the significance of Koch's Postulates in microbiology?

They provide a framework for linking specific pathogens to specific diseases.

What are Falkow's Molecular Koch's Postulates?

They extend Koch's Postulates to include molecular techniques for identifying virulence factors.

What is the theory of spontaneous generation?

The incorrect theory that living organisms can originate from nonliving matter.

How long was the theory of spontaneous generation accepted?

It was accepted for thousands of years until the mid-1800s.

What did people believe allowed nonliving matter to give rise to living beings?

People believed in a 'vital force' present in the air.

What observations led people to believe in spontaneous generation?

Living organisms seemed to suddenly arise from nonliving matter.

Who were two early supporters of the theory of spontaneous generation?

Aristotle and Jan Baptista van Helmont.

What evidence did Aristotle provide for spontaneous generation?

He suggested that life arose from non-living material using the sudden appearance of fish in puddles as evidence.

What was Jan Baptista van Helmont's claim regarding mice?

He claimed that mice could arise from rags and wheat kernels left in an open container.

What did Francesco Redi demonstrate regarding spontaneous generation?

He showed that worms on rotting meat came from eggs of flies, not spontaneous generation.

What experiment did Francesco Redi conduct?

He placed meat in two jars, covering one with gauze to prevent flies from depositing eggs.

What did Lazzaro Spallanzani do to contradict John Needham's results?

He boiled broths longer and sealed flasks by melting their necks, keeping them sterile.

What did Louis Pasteur demonstrate about air?

He demonstrated that air is filled with microorganisms.

What did Pasteur's swan-necked flask experiment show?

It showed that boiled infusions remained sterile despite being open to air.

What is biogenesis?

The production of living things from other living things.

What did John Tyndall contribute to the debate over spontaneous generation?

He explained conflicting data and showed that sterilizing broths required different times.

What was the significance of Pasteur's results?

They ended arguments that unheated air or broths contained a 'vital force' necessary for spontaneous generation.

What did some argue about the heating process in relation to spontaneous generation?

They argued that heating destroyed the 'vital force' necessary for spontaneous generation.

What did Pasteur observe when he filtered air through a cotton plug?

He observed trapped microorganisms that looked identical to those found in broths.

What did the controversy over spontaneous generation involve?

It involved multiple contributions and experiments that defined the question of whether life could arise from nonlife.

What was the outcome of the dispute over spontaneous generation?

It was resolved through experiments that demonstrated microorganisms do not arise spontaneously.

How did the understanding of spontaneous generation evolve over time?

It evolved from belief in a 'vital force' to the acceptance of biogenesis and germ theory.

What is a limitation of Koch's Postulates regarding microbial culture?

Not all microbes can be grown in culture, and it cannot explain viral diseases, prion diseases, and other infectious agents.

How do asymptomatic carriers affect Koch's Postulates?

Asymptomatic carriers, immunity, and genetic resistance can make the postulate that introduction of the pathogen always causes disease sometimes untrue.

List some ways in which microbes are essential to life on Earth.

1. Beneficial to health (normal microbiota). 2. Involved in food production. 3. Used in medicine creation. 4. Participate in ecological cycles.

What is the difference between taxonomy and phylogeny?

Taxonomy is the classification of living things, while phylogeny is the study of the evolutionary history and relationships among species.

What is the current system of classification of living things?

The current system classifies organisms into domains and kingdoms based on shared characteristics.

What are the parts of a scientific name of an organism?

A scientific name consists of two parts: the genus name (capitalized) and the species name (lowercase), both italicized.

What is the significance of normal microbiota?

Normal microbiota refers to the microbes that are normally found on/in our bodies and play a crucial role in health.

What percentage of known microbes are considered pathogenic?

Less than 1% of known microbes are pathogenic.

What are some examples of beneficial roles of microbes?

Microbes are involved in food production, medicine creation, and ecological cycles.

What is meant by 'normal flora'?

The microorganisms that are typically found in and on our bodies.

Why are some microbes considered pathogens?

Some microbes are classified as pathogens because they can cause disease in humans.

What is the role of microbes in ecological cycles?

Microbes play essential roles in nutrient cycling, such as decomposition and nitrogen fixation.

How can the presence of normal microbiota affect health?

Normal microbiota can prevent the colonization of harmful pathogens and contribute to immune system function.

What is an example of a microbe used in food production?

Yeast is commonly used in the production of bread and alcoholic beverages.

What is the impact of genetic resistance on disease causation?

Genetic resistance can prevent individuals from developing diseases even when exposed to pathogens.

What is a prion disease?

A prion disease is caused by misfolded proteins that can lead to neurodegenerative conditions.

What role do normal microbiota play in disease prevention?

They compete with pathogenic microbes for nutrients and prevent pathogens from adhering to our cells.

How do normal microbiota contribute to the immune system?

They are needed for the normal development of the immune system, helping the body distinguish between normal and pathogenic cells.

What substances do normal microbiota produce to combat pathogens?

They produce substances that are toxic to bacteria or other microorganisms.

How do microbes assist in food production?

Microbes help increase soil fertility and stability, and they increase crop yields.

What are some medicinal uses of fungi?

Fungi produce antibiotics like penicillin and cyclosporin, and they have functions in hemostasis, inflammation reduction, cholesterol reduction, and cancer treatments.

What is the significance of the genus Streptomyces in medicine?

Most antibiotics are made by soil-dwelling bacteria from the genus Streptomyces.

Name some common antibiotics derived from bacteria.

Chloramphenicol, Neomycin, Tetracycline, and Streptomycin.

What is recombinant DNA technology in the context of bacteria?

It is a technique where DNA from different species is combined and inserted into host DNA, allowing bacteria to produce large quantities of proteins.

What is one of the first examples of using bacteria for protein production?

The production of human insulin.

How are genetically-modified bacteria being researched for drug delivery?

They are being investigated to produce anti-tumor drugs inside the patient, as they can selectively grow in tumor cells.

What are vaccine vectors in microbiology?

Invasive bacteria like Salmonella and Shigella are used in attenuated form as vaccine vectors to elicit immune responses.

What are the classifications of vaccines mentioned?

Toxoids, subunit vaccines, killed whole cell vaccines, and live attenuated vaccines.

What ecological cycles do bacteria help maintain?

The Carbon Cycle, Nitrogen Cycle, Sulfur Cycle, and Phosphorus Cycle.