(1.) Intro to Microbiology: Microbes, Microbiome, Infection, and Basic Concepts

QA flashcards covering key concepts from the microbiology lecture notes.

What microscope is required to visualize viruses?

Electron microscope.

What does microbes being ubiquitous mean?

touching a doorknob can transfer microbes from your skin to the surface and vice versa,

What is the purpose of plating environmental swabs on agar plates?

To culture environmental microbes and observe colonies after incubation.

What is a colony on an agar plate?

A visible cluster of bacteria or fungi growing on the plate.

Which colony appearance suggests bacteria on an agar plate?

Smooth and shiny.

Which colony appearance suggests fungi on an agar plate?

Fuzzy, cotton-like.

How long does growth typically take on plates in this course?

About 24 to 48 hours.

Can you see intracellular structures of bacteria with a standard classroom light microscope?

No; you can only see shape and size, not internal structures.

Why are electron microscopes needed to view viruses?

Because viruses are nanoscale and too small for light microscopes.

What is a microbiome?

A group of microbes that help maintain good health and prevent pathogenic microbes from growing.

What is another term for microbiome?

Microbiota.

What does normal microbiota mean?

Microbes that are always present on or in the body.

What does 'parasitic' mean?

An organism that lives off its host and causes damage.

What does 'transient flora' refer to?

Microbes that are present temporarily and are not permanent residents.

What is a pathogen?

An organism that causes disease.

What is the difference between infection and disease?

Infection is invasion and multiplication of microorganisms; disease involves tissue destruction.

What is sepsis?

A systemic infection where microbes multiply in the blood and can cause shock, organ failure, or death.

What factors influence progression from infection to disease?

Host immune status (age, diabetes, cardiovascular issues) and the body's ability to control spread to tissues and organs.

What does endemic mean?

Always present in a population or region.

What does epidemic mean?

A large number of people in a given area become infected in a short period.

What does pandemic mean?

Worldwide spread of a disease.

Approximately how long ago did immunology, parasitology, and virology emerge as fields?

About 150 years ago.

How many millimeters are in a centimeter?

10 millimeters.

How many micrometers are in a millimeter?

1000 micrometers.

How many nanometers are in a micrometer?

1000 nanometers.

Approximately how many bacterial cells are in the human body compared to human cells?

About 40 trillion bacterial cells vs 30 trillion human cells; roughly 10 trillion more bacteria.

What do algal pigments do?

They enable photosynthesis by capturing light energy.

What is the role of hyaluronic acid in tissue invasion by bacteria?

Bacteria like Staphylococcus can degrade hyaluronic acid to facilitate tissue invasion and destruction.

What is one way the microbiome helps the immune system?

It helps discriminate threats and trains the immune system to distinguish self from non-self.

What is an astonishing fact about the abundance of microorganisms in soil?

There are more microorganisms in one teaspoon of soil than there are people on Earth.

What is a phage?

A virus that infects bacteria.

What are prions?

Infectious agents composed of misfolded proteins with no DNA/RNA inside.

What are protozoa?

Single-celled eukaryotic organisms.

What are Eukaryotes?

Organisms with complex cells containing a nucleus, including animals, plants, fungi, and protozoa.

What is the general proportion of harmful versus beneficial bacteria?

The vast majority of bacteria are harmless or beneficial; only a small percentage (less than 1\%) are pathogenic.

What conditions are necessary for microbial colonization?

Colonization can only occur at body sites that provide nutrients and the right environment for the microbes to flourish.

What was the Human Microbiome Project?

A 2007-2016 project to map the body's typical microbiota and its link to human diseases.

What is the National Microbiome Initiative?

Explores the role microbes play in different ecosystems and began in 2016.

Why was the field of microbiology developed?

To save the human population from infectious diseases.

What is infection?

A pathogen that enters the host and may or may not cause tissue destruction (e.g., common cold).

What is disease?

A pathogen enters the host and does cause tissue destruction (e.g., AIDS).