Microbiology: Overview, Microbiome, Taxonomy, History, and Staphylococcus aureus (Chapter 1)

Flashcards covering microbiology basics, microbiome concepts, taxonomy history, key figures, disease, and Staphylococcus aureus.

What are microorganisms?

Organisms too small to see with the naked eye; ubiquitous in nature; most are beneficial; only a few are pathogenic.

What is a pathogen?

An organism that causes disease.

List some roles of microorganisms in industry and the environment.

Production of cellulose and medications, use in the food industry, insect pest control, bioremediation, and research.

Why is microbiology important in healthcare?

Helps understand causes and transmission of disease to prevent epidemics, disease, and complications, including food poisoning.

What is the microbiome?

The community of microorganisms that live in and on the human body, helping maintain homeostasis, digest food, regulate immunity, protect against pathogens, and produce vitamins.

What are probiotics?

Beneficial microorganisms that are part of the microbiota.

What is the Human Microbiome Project?

A research initiative studying the microbiome in humans.

What is dysbiosis?

Imbalance in the microbiome that may contribute to disease.

How are microbiota and microbiome different?

Microbiota is the collection of microbial communities in a habitat; microbiome is the collective genome of all microbial cells in the body.

Where are gut microbiota most abundant?

In the colon (large intestine).

When does the development of gut microbiota begin?

During pregnancy, but it is primarily established after birth.

What fraction of your gut microbiota is common vs. unique?

About one-third common to others; two-thirds are specific to each person.

What are the three domains of life?

Bacteria, Archaea, and Eukarya.

What are the five kingdoms described by Whittaker?

Monera, Protists, Fungi, Plants, and Animals.

Which scientist proposed the cell theory that all living things are composed of cells?

Hooke.

Who identified various shapes of microorganisms microscopically?

Antonie van Leeuwenhoek.

What is biogenesis?

Living cells arise only from other living cells.

What is spontaneous generation?

The theory that life could arise spontaneously from nonliving matter.

What did Pasteur demonstrate about spontaneous generation?

That microbes are present in nonliving matter; fermentation and pasteurization disproved spontaneous generation.

What are Koch's four postulates?

The same pathogen must be present in every case; it must be isolated and grown in pure culture; it must cause disease when inoculated into a healthy host; it must be re-isolated from the inoculated host and shown to be the original organism.

Who developed vaccination against smallpox?

Edward Jenner.

Who discovered penicillin?

Alexander Fleming.

What are the two main types of immunity?

Innate and adaptive immunity.

Name some antibiotic-resistant infections mentioned.

MRSA, VRSA, and MDR-TB.

Name some emerging infectious diseases listed.

Zika virus; influenza subtypes H1N1 and H5N1; Ebola; SARS-CoV-2 (coronavirus).

What is Staphylococcus aureus?

Gram-positive cocci; commonly found in nasal passages; can produce toxins causing various illnesses.

What toxins can S. aureus produce?

Exfoliative toxin, heat-stable toxin, and toxic shock syndrome toxin.

What does MRSA stand for?

Methicillin-resistant Staphylococcus aureus; a common cause of hospital-acquired infections.

What types of infections can S. aureus cause on the skin?

Folliculitis, sty, impetigo, cellulitis; can lead to scalded skin syndrome, toxic shock syndrome, and necrotizing fasciitis.

What respiratory complication can S. aureus cause after influenza?

Pneumonia.

What bone infection is commonly caused by S. aureus?

Septic osteomyelitis.

What heart condition can S. aureus cause?

Acute endocarditis with destruction of heart valves.

What environments are Archaea commonly found in and do they typically cause human disease?

Often found in extreme environments; not known to cause disease in humans.

What characterizes bacteria?

Prokaryotes with peptidoglycan-containing cell walls; diverse shapes; can be seen with a light microscope.

What characterizes archaea?

Prokaryotes lacking peptidoglycan; often in extreme environments; not known to cause human disease.

What is a hallmark of fungal cell walls?

Chitin.

What are algae?

Photosynthetic eukaryotes; may be uni- or multicellular; cellulose in cell walls; produce oxygen and carbohydrates.

What are protozoa and their basic characteristics?

Unicellular eukaryotes; no cell wall; various shapes; free-loving or parasitic.

What defines viruses?

Acellular with a nucleic acid core and a protein coat; may have a lipid envelope; parasitic and seen only by electron microscope.

What are helminths?

Multicellular eukaryotic parasites (roundworms and flatworms).