Chapter 1

What is microbiology?

The study of living things too small to be seen without magnification.

Why is using the term "germs" technically inappropriate we discussing MOST microbes

Most microbes are harmless. About 5% could be considered harmful.

Fields within microbiology

Medical Microbiology- infection and disease
Public Health and Epidemiology- spread of disease, the trends, and patterns
Immunology- how immune system reacts to microbes
Industrial Microbiology- how microbes operate in environment
Agriculture Microbiology-


Found everywhere

Why is the ubiquity of microbes significant?

Microbes are everywhere we go. They are in the air, soil , every surface, skin, etc

7 types of microorganisms


What is the primary differences between prokaryotes and eukaryotes?

Prokaryotes are always single-celled and have a simple internal structure (DNA not enclosed in membrane and no cellular organelles)
Eukaryotes are single and multicellular organisms and have a complex internal structure (DNA enclosed in membrane and conta

What are the two primary types of prokaryotic organisms?

Bactria and Archaea

Is bacteria or archaea far more common and found virtually all locations of the earth?


Is bacteria or archaea considered extremophiles? Why are they called that?

They are called that because they tend to live in extreme/high conditions where most life forms cannot survive.

What are the four types of eukaryotes?

Protists (algae and Protozoa)

Which of the four eukaryotes classified as single-celled?

Protists (algae and Protozoa)

Why are algae important microscopic organisms?

They are important because they make up the base of the food chain in an aquatic ecosystem. They also produce about half the earths oxygen.

How are algae and Protozoa similar but different?

They are both members of the protisa kingdom. Algae are photosynthetic and produce their own food from the sun, while Protozoa are non-photosynthetic and must acquire food from the environment.

What are helminths?

parasitic worms

Why are helminths (worms) considered in the study of microbiology?

Because they begin life as infectious microscopic eggs and larvae


Microbes that cause disease

What are the six categories of body locations infected by pathogens?

Skin and Eyes
Nervous System
Cardiovascular and Lymphatic System
Respiratory system
Gastrointestinal Tract
Genitourinary System

What does MRSA stand for?

methicillin-resistant staphylococcus aureus

Where are most MRSA infections?


What is the name of the "brain-eating amoeba"?

Naegleria fowleri

How is brain-eating amoeba most commonly acquired?

Forced into the nasal passage (swimming, skiing, diving)

What disease does Borrelia burgdorgeri cause? How is this pathogen transmitted? What common sign (i.e. indication of infection) occurs in about 70-80% of those infected?

Borrelia burgdorgeri causes Lyme disease. It is transmitted through the bite of black-legged dear ticks. 70-80% of patients experience erythema migrans (bulls eye rash)

Symbiotic relationship

Relationship associated between two species

Three types of symbiotic relationships

Mutual- benefit both organisms
Commensalism- beneficial to only on of the two members involved, the other is unaffected
Parasitic- benefit one of the organisms but do so at the expense of the other (pathogens/parasites)

Are symbiotic relationships permanent?

No, they are subject to change. What might be mutual relationship at one point may gradually or dramatically shift into a parasitic one over time

Two groups of pathogens? What's the difference?

Opportunistic pathogens- adapt to avoid host of the immune system. Has the ability to infect individuals
Primary (true) pathogens- lack adaptions to avoid host of immune system. Tend to only infect individuals with weakened immune system (elderly, young c

Why is that a single pathogen can affect two separate host differently?

Different hosts have different levels of susceptibility to infection. Pathogens can be harmless to one host but pathogenic to another.

What is the new research indicating about the presence of pathogenic microbes in healthy people and animals?

Heathy people consistently harbor known pathogens. They appear to influence behavior, appetite, mood, and even weight gain/loss

What disease is H. pylori know to cause? What percent of the worlds population in thought to harbor H pylori

H. Pylori can cause stomach ulcers. About 50% of the worlds population is harboring H. Pylori

Scientist are making new links to old microbes. What does this mean?

New research helps to understand the role microbes play in our bodies. Gut bacteria can become dysfunctional or imbalanced, potentially leading to a disease. Gut bacteria differs in all individuals

If a scientist were to transfer the gut bacteria from an anxious mouse to calm a mouse and vice Vera, what might be excepted outcome, based on the new research?

Mice have shown that traits can be transferred along with a change in gut bacteria. After gut bacteria were wrapped the mice began to exhibit opposite behavior, calm mice being anxious and anxious mice being calm

What is an emerging disease?

an unknown disease that appears in a population for the first time or that may have existed previously but is rapidly increasing in incidence or geographic range.

Have long have scientists know about antibiotic resistance in bacteria?

Since the discovery of antibiotics

What activities increase rates of antibiotic resistance in bacteria?

Overuse and misuse

Why aren't drug companies developing more new antibiotics?

Cost of development and long term profit

Some scientist are comparing human gut bacteria to a(n) _____________ in the human body

Separate organ